| 1 | """
|
|---|
| 2 | This module provides the functionality to create the temporal
|
|---|
| 3 | SQL database and to establish a connection to the database.
|
|---|
| 4 |
|
|---|
| 5 | Usage:
|
|---|
| 6 |
|
|---|
| 7 | .. code-block:: python
|
|---|
| 8 |
|
|---|
| 9 | >>> import grass.temporal as tgis
|
|---|
| 10 | >>> # Create the temporal database
|
|---|
| 11 | >>> tgis.init()
|
|---|
| 12 | >>> # Establish a database connection
|
|---|
| 13 | >>> dbif, connected = tgis.init_dbif(None)
|
|---|
| 14 | >>> dbif.connect()
|
|---|
| 15 | >>> # Execute a SQL statement
|
|---|
| 16 | >>> dbif.execute_transaction("SELECT datetime(0, 'unixepoch', 'localtime');")
|
|---|
| 17 | >>> # Mogrify an SQL statement
|
|---|
| 18 | >>> dbif.mogrify_sql_statement(["SELECT name from raster_base where name = ?",
|
|---|
| 19 | ... ("precipitation",)])
|
|---|
| 20 | "SELECT name from raster_base where name = 'precipitation'"
|
|---|
| 21 | >>> dbif.close()
|
|---|
| 22 |
|
|---|
| 23 |
|
|---|
| 24 | (C) 2011-2014 by the GRASS Development Team
|
|---|
| 25 | This program is free software under the GNU General Public
|
|---|
| 26 | License (>=v2). Read the file COPYING that comes with GRASS
|
|---|
| 27 | for details.
|
|---|
| 28 |
|
|---|
| 29 | :author: Soeren Gebbert
|
|---|
| 30 | """
|
|---|
| 31 | #import traceback
|
|---|
| 32 | import os
|
|---|
| 33 | # i18N
|
|---|
| 34 | import gettext
|
|---|
| 35 | gettext.install('grasslibs', os.path.join(os.getenv("GISBASE"), 'locale'))
|
|---|
| 36 |
|
|---|
| 37 | try:
|
|---|
| 38 | from builtins import long
|
|---|
| 39 | except ImportError:
|
|---|
| 40 | # python3
|
|---|
| 41 | long = int
|
|---|
| 42 |
|
|---|
| 43 | import grass.script as gscript
|
|---|
| 44 | from datetime import datetime
|
|---|
| 45 | from .c_libraries_interface import *
|
|---|
| 46 | from grass.pygrass import messages
|
|---|
| 47 | # Import all supported database backends
|
|---|
| 48 | # Ignore import errors since they are checked later
|
|---|
| 49 | try:
|
|---|
| 50 | import sqlite3
|
|---|
| 51 | except ImportError:
|
|---|
| 52 | pass
|
|---|
| 53 | # Postgresql is optional, existence is checked when needed
|
|---|
| 54 | try:
|
|---|
| 55 | import psycopg2
|
|---|
| 56 | import psycopg2.extras
|
|---|
| 57 | except:
|
|---|
| 58 | pass
|
|---|
| 59 |
|
|---|
| 60 | import atexit
|
|---|
| 61 |
|
|---|
| 62 | ###############################################################################
|
|---|
| 63 |
|
|---|
| 64 |
|
|---|
| 65 | def profile_function(func):
|
|---|
| 66 | """Profiling function provided by the temporal framework"""
|
|---|
| 67 | do_profiling = os.getenv("GRASS_TGIS_PROFILE")
|
|---|
| 68 |
|
|---|
| 69 | if do_profiling is "True" or do_profiling is "1":
|
|---|
| 70 | import cProfile, pstats
|
|---|
| 71 | try:
|
|---|
| 72 | import StringIO as io
|
|---|
| 73 | except ImportError:
|
|---|
| 74 | import io
|
|---|
| 75 | pr = cProfile.Profile()
|
|---|
| 76 | pr.enable()
|
|---|
| 77 | func()
|
|---|
| 78 | pr.disable()
|
|---|
| 79 | s = io.StringIO()
|
|---|
| 80 | sortby = 'cumulative'
|
|---|
| 81 | ps = pstats.Stats(pr, stream=s).sort_stats(sortby)
|
|---|
| 82 | ps.print_stats()
|
|---|
| 83 | print(s.getvalue())
|
|---|
| 84 | else:
|
|---|
| 85 | func()
|
|---|
| 86 |
|
|---|
| 87 | # Global variable that defines the backend
|
|---|
| 88 | # of the temporal GIS
|
|---|
| 89 | # It can either be "sqlite" or "pg"
|
|---|
| 90 | tgis_backend = None
|
|---|
| 91 |
|
|---|
| 92 |
|
|---|
| 93 | def get_tgis_backend():
|
|---|
| 94 | """Return the temporal GIS backend as string
|
|---|
| 95 |
|
|---|
| 96 | :returns: either "sqlite" or "pg"
|
|---|
| 97 | """
|
|---|
| 98 | global tgis_backend
|
|---|
| 99 | return tgis_backend
|
|---|
| 100 |
|
|---|
| 101 | # Global variable that defines the database string
|
|---|
| 102 | # of the temporal GIS
|
|---|
| 103 | tgis_database = None
|
|---|
| 104 |
|
|---|
| 105 |
|
|---|
| 106 | def get_tgis_database():
|
|---|
| 107 | """Return the temporal database string specified with t.connect
|
|---|
| 108 | """
|
|---|
| 109 | global tgis_database
|
|---|
| 110 | return tgis_database
|
|---|
| 111 |
|
|---|
| 112 | # The version of the temporal framework
|
|---|
| 113 | # this value must be an integer larger than 0
|
|---|
| 114 | # Increase this value in case of backward incompatible changes in the TGIS API
|
|---|
| 115 | tgis_version = 2
|
|---|
| 116 | # The version of the temporal database since framework and database version
|
|---|
| 117 | # can differ this value must be an integer larger than 0
|
|---|
| 118 | # Increase this value in case of backward incompatible changes
|
|---|
| 119 | # temporal database SQL layout
|
|---|
| 120 | tgis_db_version = 2
|
|---|
| 121 |
|
|---|
| 122 | # We need to know the parameter style of the database backend
|
|---|
| 123 | tgis_dbmi_paramstyle = None
|
|---|
| 124 |
|
|---|
| 125 |
|
|---|
| 126 | def get_tgis_dbmi_paramstyle():
|
|---|
| 127 | """Return the temporal database backend parameter style
|
|---|
| 128 |
|
|---|
| 129 | :returns: "qmark" or ""
|
|---|
| 130 | """
|
|---|
| 131 | global tgis_dbmi_paramstyle
|
|---|
| 132 | return tgis_dbmi_paramstyle
|
|---|
| 133 |
|
|---|
| 134 | # We need to access the current mapset quite often in the framework, so we make
|
|---|
| 135 | # a global variable that will be initiated when init() is called
|
|---|
| 136 | current_mapset = None
|
|---|
| 137 | current_location = None
|
|---|
| 138 | current_gisdbase = None
|
|---|
| 139 |
|
|---|
| 140 | ###############################################################################
|
|---|
| 141 |
|
|---|
| 142 |
|
|---|
| 143 | def get_current_mapset():
|
|---|
| 144 | """Return the current mapset
|
|---|
| 145 |
|
|---|
| 146 | This is the fastest way to receive the current mapset.
|
|---|
| 147 | The current mapset is set by init() and stored in a global variable.
|
|---|
| 148 | This function provides access to this global variable.
|
|---|
| 149 | """
|
|---|
| 150 | global current_mapset
|
|---|
| 151 | return current_mapset
|
|---|
| 152 |
|
|---|
| 153 | ###############################################################################
|
|---|
| 154 |
|
|---|
| 155 |
|
|---|
| 156 | def get_current_location():
|
|---|
| 157 | """Return the current location
|
|---|
| 158 |
|
|---|
| 159 | This is the fastest way to receive the current location.
|
|---|
| 160 | The current location is set by init() and stored in a global variable.
|
|---|
| 161 | This function provides access to this global variable.
|
|---|
| 162 | """
|
|---|
| 163 | global current_location
|
|---|
| 164 | return current_location
|
|---|
| 165 |
|
|---|
| 166 | ###############################################################################
|
|---|
| 167 |
|
|---|
| 168 |
|
|---|
| 169 | def get_current_gisdbase():
|
|---|
| 170 | """Return the current gis database (gisdbase)
|
|---|
| 171 |
|
|---|
| 172 | This is the fastest way to receive the current gisdbase.
|
|---|
| 173 | The current gisdbase is set by init() and stored in a global variable.
|
|---|
| 174 | This function provides access to this global variable.
|
|---|
| 175 | """
|
|---|
| 176 | global current_gisdbase
|
|---|
| 177 | return current_gisdbase
|
|---|
| 178 |
|
|---|
| 179 | ###############################################################################
|
|---|
| 180 |
|
|---|
| 181 | # If this global variable is set True, then maps can only be registered in
|
|---|
| 182 | # space time datasets with the same mapset. In addition, only maps in the
|
|---|
| 183 | # current mapset can be inserted, updated or deleted from the temporal database.
|
|---|
| 184 | # Overwrite this global variable by: g.gisenv set="TGIS_DISABLE_MAPSET_CHECK=True"
|
|---|
| 185 | # ATTENTION: Be aware to face corrupted temporal database in case this global
|
|---|
| 186 | # variable is set to False. This feature is highly
|
|---|
| 187 | # experimental and violates the grass permission guidance.
|
|---|
| 188 | enable_mapset_check = True
|
|---|
| 189 | # If this global variable is set True, the timestamps of maps will be written
|
|---|
| 190 | # as textfiles for each map that will be inserted or updated in the temporal
|
|---|
| 191 | # database using the C-library timestamp interface.
|
|---|
| 192 | # Overwrite this global variable by: g.gisenv set="TGIS_DISABLE_TIMESTAMP_WRITE=True"
|
|---|
| 193 | # ATTENTION: Be aware to face corrupted temporal database in case this global
|
|---|
| 194 | # variable is set to False. This feature is highly
|
|---|
| 195 | # experimental and violates the grass permission guidance.
|
|---|
| 196 | enable_timestamp_write = True
|
|---|
| 197 |
|
|---|
| 198 |
|
|---|
| 199 | def get_enable_mapset_check():
|
|---|
| 200 | """Return True if the mapsets should be checked while insert, update,
|
|---|
| 201 | delete requests and space time dataset registration.
|
|---|
| 202 |
|
|---|
| 203 | If this global variable is set True, then maps can only be registered
|
|---|
| 204 | in space time datasets with the same mapset. In addition, only maps in
|
|---|
| 205 | the current mapset can be inserted, updated or deleted from the temporal
|
|---|
| 206 | database.
|
|---|
| 207 | Overwrite this global variable by: g.gisenv set="TGIS_DISABLE_MAPSET_CHECK=True"
|
|---|
| 208 |
|
|---|
| 209 | ..warning::
|
|---|
| 210 |
|
|---|
| 211 | Be aware to face corrupted temporal database in case this
|
|---|
| 212 | global variable is set to False. This feature is highly
|
|---|
| 213 | experimental and violates the grass permission guidance.
|
|---|
| 214 |
|
|---|
| 215 | """
|
|---|
| 216 | global enable_mapset_check
|
|---|
| 217 | return enable_mapset_check
|
|---|
| 218 |
|
|---|
| 219 |
|
|---|
| 220 | def get_enable_timestamp_write():
|
|---|
| 221 | """Return True if the map timestamps should be written to the spatial
|
|---|
| 222 | database metadata as well.
|
|---|
| 223 |
|
|---|
| 224 | If this global variable is set True, the timestamps of maps will be
|
|---|
| 225 | written as textfiles for each map that will be inserted or updated in
|
|---|
| 226 | the temporal database using the C-library timestamp interface.
|
|---|
| 227 | Overwrite this global variable by: g.gisenv set="TGIS_DISABLE_TIMESTAMP_WRITE=True"
|
|---|
| 228 |
|
|---|
| 229 | ..warning::
|
|---|
| 230 |
|
|---|
| 231 | Be aware that C-libraries can not access timestamp information if
|
|---|
| 232 | they are not written as spatial database metadata, hence modules
|
|---|
| 233 | that make use of timestamps using the C-library interface will not
|
|---|
| 234 | work with maps that were created without writing the timestamps.
|
|---|
| 235 | """
|
|---|
| 236 | global enable_timestamp_write
|
|---|
| 237 | return enable_timestamp_write
|
|---|
| 238 |
|
|---|
| 239 | ###############################################################################
|
|---|
| 240 |
|
|---|
| 241 | # The global variable that stores the PyGRASS Messenger object that
|
|---|
| 242 | # provides a fast and exit safe interface to the C-library message functions
|
|---|
| 243 | message_interface = None
|
|---|
| 244 |
|
|---|
| 245 |
|
|---|
| 246 | def _init_tgis_message_interface(raise_on_error=False):
|
|---|
| 247 | """Initiate the global message interface
|
|---|
| 248 |
|
|---|
| 249 | :param raise_on_error: If True raise a FatalError exception in case of
|
|---|
| 250 | a fatal error, call sys.exit(1) otherwise
|
|---|
| 251 | """
|
|---|
| 252 | global message_interface
|
|---|
| 253 | if message_interface is None:
|
|---|
| 254 | message_interface = messages.get_msgr(raise_on_error=raise_on_error)
|
|---|
| 255 |
|
|---|
| 256 |
|
|---|
| 257 | def get_tgis_message_interface():
|
|---|
| 258 | """Return the temporal GIS message interface which is of type
|
|---|
| 259 | grass.pygrass.message.Messenger()
|
|---|
| 260 |
|
|---|
| 261 | Use this message interface to print messages to stdout using the
|
|---|
| 262 | GRASS C-library messaging system.
|
|---|
| 263 | """
|
|---|
| 264 | global message_interface
|
|---|
| 265 | return message_interface
|
|---|
| 266 |
|
|---|
| 267 | ###############################################################################
|
|---|
| 268 |
|
|---|
| 269 | # The global variable that stores the C-library interface object that
|
|---|
| 270 | # provides a fast and exit safe interface to the C-library libgis,
|
|---|
| 271 | # libraster, libraster3d and libvector functions
|
|---|
| 272 | c_library_interface = None
|
|---|
| 273 |
|
|---|
| 274 |
|
|---|
| 275 | def _init_tgis_c_library_interface():
|
|---|
| 276 | """Set the global C-library interface variable that
|
|---|
| 277 | provides a fast and exit safe interface to the C-library libgis,
|
|---|
| 278 | libraster, libraster3d and libvector functions
|
|---|
| 279 | """
|
|---|
| 280 | global c_library_interface
|
|---|
| 281 | if c_library_interface is None:
|
|---|
| 282 | c_library_interface = CLibrariesInterface()
|
|---|
| 283 |
|
|---|
| 284 |
|
|---|
| 285 | def get_tgis_c_library_interface():
|
|---|
| 286 | """Return the C-library interface that
|
|---|
| 287 | provides a fast and exit safe interface to the C-library libgis,
|
|---|
| 288 | libraster, libraster3d and libvector functions
|
|---|
| 289 | """
|
|---|
| 290 | global c_library_interface
|
|---|
| 291 | return c_library_interface
|
|---|
| 292 |
|
|---|
| 293 | ###############################################################################
|
|---|
| 294 |
|
|---|
| 295 | # Set this variable True to raise a FatalError exception
|
|---|
| 296 | # in case a fatal error occurs using the messenger interface
|
|---|
| 297 | raise_on_error = False
|
|---|
| 298 |
|
|---|
| 299 |
|
|---|
| 300 | def set_raise_on_error(raise_exp=True):
|
|---|
| 301 | """Define behavior on fatal error, invoked using the tgis messenger
|
|---|
| 302 | interface (msgr.fatal())
|
|---|
| 303 |
|
|---|
| 304 | The messenger interface will be restarted using the new error policy
|
|---|
| 305 |
|
|---|
| 306 | :param raise_exp: True to raise a FatalError exception instead of calling
|
|---|
| 307 | sys.exit(1) when using the tgis messenger interface
|
|---|
| 308 |
|
|---|
| 309 | .. code-block:: python
|
|---|
| 310 |
|
|---|
| 311 | >>> import grass.temporal as tgis
|
|---|
| 312 | >>> tgis.init()
|
|---|
| 313 | >>> ignore = tgis.set_raise_on_error(False)
|
|---|
| 314 | >>> msgr = tgis.get_tgis_message_interface()
|
|---|
| 315 | >>> tgis.get_raise_on_error()
|
|---|
| 316 | False
|
|---|
| 317 | >>> msgr.fatal("Ohh no no no!")
|
|---|
| 318 | Traceback (most recent call last):
|
|---|
| 319 | File "__init__.py", line 239, in fatal
|
|---|
| 320 | sys.exit(1)
|
|---|
| 321 | SystemExit: 1
|
|---|
| 322 |
|
|---|
| 323 | >>> tgis.set_raise_on_error(True)
|
|---|
| 324 | False
|
|---|
| 325 | >>> msgr.fatal("Ohh no no no!")
|
|---|
| 326 | Traceback (most recent call last):
|
|---|
| 327 | File "__init__.py", line 241, in fatal
|
|---|
| 328 | raise FatalError(message)
|
|---|
| 329 | FatalError: Ohh no no no!
|
|---|
| 330 |
|
|---|
| 331 | :returns: current status
|
|---|
| 332 | """
|
|---|
| 333 | global raise_on_error
|
|---|
| 334 | tmp_raise = raise_on_error
|
|---|
| 335 | raise_on_error = raise_exp
|
|---|
| 336 |
|
|---|
| 337 | global message_interface
|
|---|
| 338 | if message_interface:
|
|---|
| 339 | message_interface.set_raise_on_error(raise_on_error)
|
|---|
| 340 | else:
|
|---|
| 341 | _init_tgis_message_interface(raise_on_error)
|
|---|
| 342 |
|
|---|
| 343 | return tmp_raise
|
|---|
| 344 |
|
|---|
| 345 |
|
|---|
| 346 | def get_raise_on_error():
|
|---|
| 347 | """Return True if a FatalError exception is raised instead of calling
|
|---|
| 348 | sys.exit(1) in case a fatal error was invoked with msgr.fatal()
|
|---|
| 349 | """
|
|---|
| 350 | global raise_on_error
|
|---|
| 351 | return raise_on_error
|
|---|
| 352 |
|
|---|
| 353 |
|
|---|
| 354 | ###############################################################################
|
|---|
| 355 |
|
|---|
| 356 |
|
|---|
| 357 | def get_tgis_version():
|
|---|
| 358 | """Get the version number of the temporal framework
|
|---|
| 359 | :returns: The version number of the temporal framework as string
|
|---|
| 360 | """
|
|---|
| 361 | global tgis_version
|
|---|
| 362 | return tgis_version
|
|---|
| 363 |
|
|---|
| 364 | ###############################################################################
|
|---|
| 365 |
|
|---|
| 366 |
|
|---|
| 367 | def get_tgis_db_version():
|
|---|
| 368 | """Get the version number of the temporal framework
|
|---|
| 369 | :returns: The version number of the temporal framework as string
|
|---|
| 370 | """
|
|---|
| 371 | global tgis_db_version
|
|---|
| 372 | return tgis_db_version
|
|---|
| 373 |
|
|---|
| 374 | ###############################################################################
|
|---|
| 375 |
|
|---|
| 376 |
|
|---|
| 377 | def get_tgis_metadata(dbif=None):
|
|---|
| 378 | """Return the tgis metadata table as a list of rows (dicts) or None if not
|
|---|
| 379 | present
|
|---|
| 380 |
|
|---|
| 381 | :param dbif: The database interface to be used
|
|---|
| 382 | :returns: The selected rows with key/value columns or None
|
|---|
| 383 | """
|
|---|
| 384 |
|
|---|
| 385 | dbif, connected = init_dbif(dbif)
|
|---|
| 386 |
|
|---|
| 387 | # Select metadata if the table is present
|
|---|
| 388 | try:
|
|---|
| 389 | statement = "SELECT * FROM tgis_metadata;\n"
|
|---|
| 390 | dbif.execute(statement)
|
|---|
| 391 | rows = dbif.fetchall()
|
|---|
| 392 | except:
|
|---|
| 393 | rows = None
|
|---|
| 394 |
|
|---|
| 395 | if connected:
|
|---|
| 396 | dbif.close()
|
|---|
| 397 |
|
|---|
| 398 | return rows
|
|---|
| 399 |
|
|---|
| 400 | ###############################################################################
|
|---|
| 401 |
|
|---|
| 402 | # The temporal database string set with t.connect
|
|---|
| 403 | # with substituted GRASS variables gisdbase, location and mapset
|
|---|
| 404 | tgis_database_string = None
|
|---|
| 405 |
|
|---|
| 406 |
|
|---|
| 407 | def get_tgis_database_string():
|
|---|
| 408 | """Return the preprocessed temporal database string
|
|---|
| 409 |
|
|---|
| 410 | This string is the temporal database string set with t.connect
|
|---|
| 411 | that was processed to substitue location, gisdbase and mapset
|
|---|
| 412 | variables.
|
|---|
| 413 | """
|
|---|
| 414 | global tgis_database_string
|
|---|
| 415 | return tgis_database_string
|
|---|
| 416 |
|
|---|
| 417 | ###############################################################################
|
|---|
| 418 |
|
|---|
| 419 |
|
|---|
| 420 | def get_sql_template_path():
|
|---|
| 421 | base = os.getenv("GISBASE")
|
|---|
| 422 | base_etc = os.path.join(base, "etc")
|
|---|
| 423 | return os.path.join(base_etc, "sql")
|
|---|
| 424 |
|
|---|
| 425 | ###############################################################################
|
|---|
| 426 |
|
|---|
| 427 |
|
|---|
| 428 | def stop_subprocesses():
|
|---|
| 429 | """Stop the messenger and C-interface subprocesses
|
|---|
| 430 | that are started by tgis.init()
|
|---|
| 431 | """
|
|---|
| 432 | global message_interface
|
|---|
| 433 | global c_library_interface
|
|---|
| 434 | if message_interface:
|
|---|
| 435 | message_interface.stop()
|
|---|
| 436 | if c_library_interface:
|
|---|
| 437 | c_library_interface.stop()
|
|---|
| 438 |
|
|---|
| 439 | # We register this function to be called at exit
|
|---|
| 440 | atexit.register(stop_subprocesses)
|
|---|
| 441 |
|
|---|
| 442 |
|
|---|
| 443 | def get_available_temporal_mapsets():
|
|---|
| 444 | """Return a list of of mapset names with temporal database driver and names
|
|---|
| 445 | that are accessible from the current mapset.
|
|---|
| 446 |
|
|---|
| 447 | :returns: A dictionary, mapset names are keys, the tuple (driver,
|
|---|
| 448 | database) are the values
|
|---|
| 449 | """
|
|---|
| 450 | global c_library_interface
|
|---|
| 451 | global message_interface
|
|---|
| 452 |
|
|---|
| 453 | mapsets = c_library_interface.available_mapsets()
|
|---|
| 454 |
|
|---|
| 455 | tgis_mapsets = {}
|
|---|
| 456 |
|
|---|
| 457 | for mapset in mapsets:
|
|---|
| 458 | driver = c_library_interface.get_driver_name(mapset)
|
|---|
| 459 | database = c_library_interface.get_database_name(mapset)
|
|---|
| 460 |
|
|---|
| 461 | message_interface.debug(1, "get_available_temporal_mapsets: "\
|
|---|
| 462 | "\n mapset %s\n driver %s\n database %s"%(mapset,
|
|---|
| 463 | driver, database))
|
|---|
| 464 |
|
|---|
| 465 | if driver and database:
|
|---|
| 466 | # Check if the temporal sqlite database exists
|
|---|
| 467 | # We need to set non-existing databases in case the mapset is the current mapset
|
|---|
| 468 | # to create it
|
|---|
| 469 | if (driver == "sqlite" and os.path.exists(database)) or mapset == get_current_mapset() :
|
|---|
| 470 | tgis_mapsets[mapset] = (driver, database)
|
|---|
| 471 |
|
|---|
| 472 | # We need to warn if the connection is defined but the database does not
|
|---|
| 473 | # exists
|
|---|
| 474 | if driver == "sqlite" and not os.path.exists(database):
|
|---|
| 475 | message_interface.warning("Temporal database connection defined as:\n" + \
|
|---|
| 476 | database + "\nBut database file does not exist.")
|
|---|
| 477 |
|
|---|
| 478 | return tgis_mapsets
|
|---|
| 479 |
|
|---|
| 480 | ###############################################################################
|
|---|
| 481 |
|
|---|
| 482 |
|
|---|
| 483 | def init(raise_fatal_error=False):
|
|---|
| 484 | """This function set the correct database backend from GRASS environmental
|
|---|
| 485 | variables and creates the grass temporal database structure for raster,
|
|---|
| 486 | vector and raster3d maps as well as for the space-time datasets strds,
|
|---|
| 487 | str3ds and stvds in case it does not exist.
|
|---|
| 488 |
|
|---|
| 489 | Several global variables are initiated and the messenger and C-library
|
|---|
| 490 | interface subprocesses are spawned.
|
|---|
| 491 |
|
|---|
| 492 | Re-run this function in case the following GRASS variables change while
|
|---|
| 493 | the process runs:
|
|---|
| 494 |
|
|---|
| 495 | - MAPSET
|
|---|
| 496 | - LOCATION_NAME
|
|---|
| 497 | - GISDBASE
|
|---|
| 498 | - TGIS_DISABLE_MAPSET_CHECK
|
|---|
| 499 | - TGIS_DISABLE_TIMESTAMP_WRITE
|
|---|
| 500 |
|
|---|
| 501 | Re-run this function if the following t.connect variables change while
|
|---|
| 502 | the process runs:
|
|---|
| 503 |
|
|---|
| 504 | - temporal GIS driver (set by t.connect driver=)
|
|---|
| 505 | - temporal GIS database (set by t.connect database=)
|
|---|
| 506 |
|
|---|
| 507 | The following environmental variables are checked:
|
|---|
| 508 |
|
|---|
| 509 | - GRASS_TGIS_PROFILE (True, False, 1, 0)
|
|---|
| 510 | - GRASS_TGIS_RAISE_ON_ERROR (True, False, 1, 0)
|
|---|
| 511 |
|
|---|
| 512 | ..warning::
|
|---|
| 513 |
|
|---|
| 514 | This functions must be called before any spatio-temporal processing
|
|---|
| 515 | can be started
|
|---|
| 516 |
|
|---|
| 517 | :param raise_fatal_error: Set this True to assure that the init()
|
|---|
| 518 | function does not kill a persistent process
|
|---|
| 519 | like the GUI. If set True a
|
|---|
| 520 | grass.pygrass.messages.FatalError
|
|---|
| 521 | exception will be raised in case a fatal
|
|---|
| 522 | error occurs in the init process, otherwise
|
|---|
| 523 | sys.exit(1) will be called.
|
|---|
| 524 | """
|
|---|
| 525 | # We need to set the correct database backend and several global variables
|
|---|
| 526 | # from the GRASS mapset specific environment variables of g.gisenv and t.connect
|
|---|
| 527 | global tgis_backend
|
|---|
| 528 | global tgis_database
|
|---|
| 529 | global tgis_database_string
|
|---|
| 530 | global tgis_dbmi_paramstyle
|
|---|
| 531 | global raise_on_error
|
|---|
| 532 | global enable_mapset_check
|
|---|
| 533 | global enable_timestamp_write
|
|---|
| 534 | global current_mapset
|
|---|
| 535 | global current_location
|
|---|
| 536 | global current_gisdbase
|
|---|
| 537 |
|
|---|
| 538 | raise_on_error = raise_fatal_error
|
|---|
| 539 |
|
|---|
| 540 | # We must run t.connect at first to create the temporal database and to
|
|---|
| 541 | # get the environmental variables
|
|---|
| 542 | gscript.run_command("t.connect", flags="c")
|
|---|
| 543 | grassenv = gscript.gisenv()
|
|---|
| 544 |
|
|---|
| 545 | # Set the global variable for faster access
|
|---|
| 546 | current_mapset = grassenv["MAPSET"]
|
|---|
| 547 | current_location = grassenv["LOCATION_NAME"]
|
|---|
| 548 | current_gisdbase = grassenv["GISDBASE"]
|
|---|
| 549 |
|
|---|
| 550 | # Check environment variable GRASS_TGIS_RAISE_ON_ERROR
|
|---|
| 551 | if os.getenv("GRASS_TGIS_RAISE_ON_ERROR") == "True" or \
|
|---|
| 552 | os.getenv("GRASS_TGIS_RAISE_ON_ERROR") == "1":
|
|---|
| 553 | raise_on_error = True
|
|---|
| 554 |
|
|---|
| 555 | # Check if the script library raises on error,
|
|---|
| 556 | # if so we do the same
|
|---|
| 557 | if gscript.get_raise_on_error() is True:
|
|---|
| 558 | raise_on_error = True
|
|---|
| 559 |
|
|---|
| 560 | # Start the GRASS message interface server
|
|---|
| 561 | _init_tgis_message_interface(raise_on_error)
|
|---|
| 562 | # Start the C-library interface server
|
|---|
| 563 | _init_tgis_c_library_interface()
|
|---|
| 564 | msgr = get_tgis_message_interface()
|
|---|
| 565 | msgr.debug(1, "Initiate the temporal database")
|
|---|
| 566 | #"\n traceback:%s"%(str(" \n".join(traceback.format_stack()))))
|
|---|
| 567 |
|
|---|
| 568 | ciface = get_tgis_c_library_interface()
|
|---|
| 569 | driver_string = ciface.get_driver_name()
|
|---|
| 570 | database_string = ciface.get_database_name()
|
|---|
| 571 |
|
|---|
| 572 | # Set the mapset check and the timestamp write
|
|---|
| 573 | if "TGIS_DISABLE_MAPSET_CHECK" in grassenv:
|
|---|
| 574 | if grassenv["TGIS_DISABLE_MAPSET_CHECK"] == "True" or \
|
|---|
| 575 | grassenv["TGIS_DISABLE_MAPSET_CHECK"] == "1":
|
|---|
| 576 | enable_mapset_check = False
|
|---|
| 577 | msgr.warning("TGIS_DISABLE_MAPSET_CHECK is True")
|
|---|
| 578 |
|
|---|
| 579 | if "TGIS_DISABLE_TIMESTAMP_WRITE" in grassenv:
|
|---|
| 580 | if grassenv["TGIS_DISABLE_TIMESTAMP_WRITE"] == "True" or \
|
|---|
| 581 | grassenv["TGIS_DISABLE_TIMESTAMP_WRITE"] == "1":
|
|---|
| 582 | enable_timestamp_write = False
|
|---|
| 583 | msgr.warning("TGIS_DISABLE_TIMESTAMP_WRITE is True")
|
|---|
| 584 |
|
|---|
| 585 | if driver_string is not None and driver_string is not "":
|
|---|
| 586 | if driver_string == "sqlite":
|
|---|
| 587 | tgis_backend = driver_string
|
|---|
| 588 | try:
|
|---|
| 589 | import sqlite3
|
|---|
| 590 | except ImportError:
|
|---|
| 591 | msgr.error("Unable to locate the sqlite SQL Python interface"
|
|---|
| 592 | " module sqlite3.")
|
|---|
| 593 | raise
|
|---|
| 594 | dbmi = sqlite3
|
|---|
| 595 | elif driver_string == "pg":
|
|---|
| 596 | tgis_backend = driver_string
|
|---|
| 597 | try:
|
|---|
| 598 | import psycopg2
|
|---|
| 599 | except ImportError:
|
|---|
| 600 | msgr.error("Unable to locate the Postgresql SQL Python "
|
|---|
| 601 | "interface module psycopg2.")
|
|---|
| 602 | raise
|
|---|
| 603 | dbmi = psycopg2
|
|---|
| 604 | else:
|
|---|
| 605 | msgr.fatal(_("Unable to initialize the temporal DBMI interface. "
|
|---|
| 606 | "Please use t.connect to specify the driver and the"
|
|---|
| 607 | " database string"))
|
|---|
| 608 | else:
|
|---|
| 609 | # Set the default sqlite3 connection in case nothing was defined
|
|---|
| 610 | gscript.run_command("t.connect", flags="d")
|
|---|
| 611 | driver_string = ciface.get_driver_name()
|
|---|
| 612 | database_string = ciface.get_database_name()
|
|---|
| 613 | tgis_backend = driver_string
|
|---|
| 614 | dbmi = sqlite3
|
|---|
| 615 |
|
|---|
| 616 | tgis_database_string = database_string
|
|---|
| 617 | # Set the parameter style
|
|---|
| 618 | tgis_dbmi_paramstyle = dbmi.paramstyle
|
|---|
| 619 |
|
|---|
| 620 | # We do not know if the database already exists
|
|---|
| 621 | db_exists = False
|
|---|
| 622 | dbif = SQLDatabaseInterfaceConnection()
|
|---|
| 623 |
|
|---|
| 624 | # Check if the database already exists
|
|---|
| 625 | if tgis_backend == "sqlite":
|
|---|
| 626 | # Check path of the sqlite database
|
|---|
| 627 | if os.path.exists(tgis_database_string):
|
|---|
| 628 | dbif.connect()
|
|---|
| 629 | # Check for raster_base table
|
|---|
| 630 | dbif.execute("SELECT name FROM sqlite_master WHERE type='table' "
|
|---|
| 631 | "AND name='raster_base';")
|
|---|
| 632 | name = dbif.fetchone()
|
|---|
| 633 | if name and name[0] == "raster_base":
|
|---|
| 634 | db_exists = True
|
|---|
| 635 | dbif.close()
|
|---|
| 636 | elif tgis_backend == "pg":
|
|---|
| 637 | # Connect to database
|
|---|
| 638 | dbif.connect()
|
|---|
| 639 | # Check for raster_base table
|
|---|
| 640 | dbif.execute("SELECT EXISTS(SELECT * FROM information_schema.tables "
|
|---|
| 641 | "WHERE table_name=%s)", ('raster_base',))
|
|---|
| 642 | if dbif.fetchone()[0]:
|
|---|
| 643 | db_exists = True
|
|---|
| 644 |
|
|---|
| 645 | backup_howto = "The format of your actual temporal database is not " \
|
|---|
| 646 | "supported any more.\nSolution: You need to export it by " \
|
|---|
| 647 | "restoring the GRASS GIS version used for creating this DB"\
|
|---|
| 648 | ". From there, create a backup of your temporal database "\
|
|---|
| 649 | "to avoid the loss of your temporal data.\nNotes: Use " \
|
|---|
| 650 | "t.rast.export and t.vect.export to make a backup of your" \
|
|---|
| 651 | " existing space time datasets.To safe the timestamps of" \
|
|---|
| 652 | " your existing maps and space time datasets, use " \
|
|---|
| 653 | "t.rast.list, t.vect.list and t.rast3d.list. "\
|
|---|
| 654 | "You can register the existing time stamped maps easily if"\
|
|---|
| 655 | " you export columns=id,start_time,end_time into text "\
|
|---|
| 656 | "files and use t.register to register them again in new" \
|
|---|
| 657 | " created space time datasets (t.create). After the backup"\
|
|---|
| 658 | " remove the existing temporal database, a new one will be"\
|
|---|
| 659 | " created automatically.\n"
|
|---|
| 660 |
|
|---|
| 661 | if db_exists is True:
|
|---|
| 662 | # Check the version of the temporal database
|
|---|
| 663 | dbif.close()
|
|---|
| 664 | dbif.connect()
|
|---|
| 665 | metadata = get_tgis_metadata(dbif)
|
|---|
| 666 | dbif.close()
|
|---|
| 667 | if metadata is None:
|
|---|
| 668 | msgr.fatal(_("Unable to receive temporal database metadata.\n"
|
|---|
| 669 | "Current temporal database info:%(info)s") % (
|
|---|
| 670 | {"info": get_database_info_string()}))
|
|---|
| 671 | for entry in metadata:
|
|---|
| 672 | if "tgis_version" in entry and entry[1] != str(get_tgis_version()):
|
|---|
| 673 | msgr.fatal(_("Unsupported temporal database: version mismatch."
|
|---|
| 674 | "\n %(backup)s Supported temporal API version is:"
|
|---|
| 675 | " %(api)i.\nPlease update your GRASS GIS "
|
|---|
| 676 | "installation.\nCurrent temporal database info:"
|
|---|
| 677 | "%(info)s") % ({"backup": backup_howto,
|
|---|
| 678 | "api": get_tgis_version(),
|
|---|
| 679 | "info": get_database_info_string()}))
|
|---|
| 680 | if "tgis_db_version" in entry and entry[1] != str(get_tgis_db_version()):
|
|---|
| 681 | msgr.fatal(_("Unsupported temporal database: version mismatch."
|
|---|
| 682 | "\n %(backup)sSupported temporal database version"
|
|---|
| 683 | " is: %(tdb)i\nCurrent temporal database info:"
|
|---|
| 684 | "%(info)s") % ({"backup": backup_howto,
|
|---|
| 685 | "tdb": get_tgis_version(),
|
|---|
| 686 | "info": get_database_info_string()}))
|
|---|
| 687 | return
|
|---|
| 688 |
|
|---|
| 689 | create_temporal_database(dbif)
|
|---|
| 690 |
|
|---|
| 691 | ###############################################################################
|
|---|
| 692 |
|
|---|
| 693 |
|
|---|
| 694 | def get_database_info_string():
|
|---|
| 695 | dbif = SQLDatabaseInterfaceConnection()
|
|---|
| 696 |
|
|---|
| 697 | info = "\nDBMI interface:..... " + str(dbif.get_dbmi().__name__)
|
|---|
| 698 | info += "\nTemporal database:.. " + str(get_tgis_database_string())
|
|---|
| 699 | return info
|
|---|
| 700 |
|
|---|
| 701 | ###############################################################################
|
|---|
| 702 |
|
|---|
| 703 |
|
|---|
| 704 | def create_temporal_database(dbif):
|
|---|
| 705 | """This function will create the temporal database
|
|---|
| 706 |
|
|---|
| 707 | It will create all tables and triggers that are needed to run
|
|---|
| 708 | the temporal GIS
|
|---|
| 709 |
|
|---|
| 710 | :param dbif: The database interface to be used
|
|---|
| 711 | """
|
|---|
| 712 | global tgis_backend
|
|---|
| 713 | global tgis_version
|
|---|
| 714 | global tgis_db_version
|
|---|
| 715 | global tgis_database_string
|
|---|
| 716 |
|
|---|
| 717 | template_path = get_sql_template_path()
|
|---|
| 718 | msgr = get_tgis_message_interface()
|
|---|
| 719 |
|
|---|
| 720 | # Read all SQL scripts and templates
|
|---|
| 721 | map_tables_template_sql = open(os.path.join(
|
|---|
| 722 | template_path, "map_tables_template.sql"), 'r').read()
|
|---|
| 723 | raster_metadata_sql = open(os.path.join(
|
|---|
| 724 | get_sql_template_path(), "raster_metadata_table.sql"), 'r').read()
|
|---|
| 725 | raster3d_metadata_sql = open(os.path.join(template_path,
|
|---|
| 726 | "raster3d_metadata_table.sql"),
|
|---|
| 727 | 'r').read()
|
|---|
| 728 | vector_metadata_sql = open(os.path.join(template_path,
|
|---|
| 729 | "vector_metadata_table.sql"),
|
|---|
| 730 | 'r').read()
|
|---|
| 731 | raster_views_sql = open(os.path.join(template_path, "raster_views.sql"),
|
|---|
| 732 | 'r').read()
|
|---|
| 733 | raster3d_views_sql = open(os.path.join(template_path,
|
|---|
| 734 | "raster3d_views.sql"), 'r').read()
|
|---|
| 735 | vector_views_sql = open(os.path.join(template_path, "vector_views.sql"),
|
|---|
| 736 | 'r').read()
|
|---|
| 737 |
|
|---|
| 738 | stds_tables_template_sql = open(os.path.join(template_path,
|
|---|
| 739 | "stds_tables_template.sql"),
|
|---|
| 740 | 'r').read()
|
|---|
| 741 | strds_metadata_sql = open(os.path.join(template_path,
|
|---|
| 742 | "strds_metadata_table.sql"),
|
|---|
| 743 | 'r').read()
|
|---|
| 744 | str3ds_metadata_sql = open(os.path.join(template_path,
|
|---|
| 745 | "str3ds_metadata_table.sql"),
|
|---|
| 746 | 'r').read()
|
|---|
| 747 | stvds_metadata_sql = open(os.path.join(template_path,
|
|---|
| 748 | "stvds_metadata_table.sql"),
|
|---|
| 749 | 'r').read()
|
|---|
| 750 | strds_views_sql = open(os.path.join(template_path, "strds_views.sql"),
|
|---|
| 751 | 'r').read()
|
|---|
| 752 | str3ds_views_sql = open(os.path.join(template_path, "str3ds_views.sql"),
|
|---|
| 753 | 'r').read()
|
|---|
| 754 | stvds_views_sql = open(os.path.join(template_path, "stvds_views.sql"),
|
|---|
| 755 | 'r').read()
|
|---|
| 756 |
|
|---|
| 757 | # Create the raster, raster3d and vector tables SQL statements
|
|---|
| 758 | raster_tables_sql = map_tables_template_sql.replace("GRASS_MAP", "raster")
|
|---|
| 759 | vector_tables_sql = map_tables_template_sql.replace("GRASS_MAP", "vector")
|
|---|
| 760 | raster3d_tables_sql = map_tables_template_sql.replace(
|
|---|
| 761 | "GRASS_MAP", "raster3d")
|
|---|
| 762 |
|
|---|
| 763 | # Create the space-time raster, raster3d and vector dataset tables
|
|---|
| 764 | # SQL statements
|
|---|
| 765 | strds_tables_sql = stds_tables_template_sql.replace("STDS", "strds")
|
|---|
| 766 | stvds_tables_sql = stds_tables_template_sql.replace("STDS", "stvds")
|
|---|
| 767 | str3ds_tables_sql = stds_tables_template_sql.replace("STDS", "str3ds")
|
|---|
| 768 |
|
|---|
| 769 | msgr.message(_("Creating temporal database: %s" % (str(tgis_database_string))))
|
|---|
| 770 |
|
|---|
| 771 | if tgis_backend == "sqlite":
|
|---|
| 772 | # We need to create the sqlite3 database path if it does not exist
|
|---|
| 773 | tgis_dir = os.path.dirname(tgis_database_string)
|
|---|
| 774 | if not os.path.exists(tgis_dir):
|
|---|
| 775 | try:
|
|---|
| 776 | os.makedirs(tgis_dir)
|
|---|
| 777 | except Exception as e:
|
|---|
| 778 | msgr.fatal(_("Unable to create SQLite temporal database\n"
|
|---|
| 779 | "Exception: %s\nPlease use t.connect to set a "
|
|---|
| 780 | "read- and writable temporal database path" % (e)))
|
|---|
| 781 |
|
|---|
| 782 | # Set up the trigger that takes care of
|
|---|
| 783 | # the correct deletion of entries across the different tables
|
|---|
| 784 | delete_trigger_sql = open(os.path.join(template_path,
|
|---|
| 785 | "sqlite3_delete_trigger.sql"),
|
|---|
| 786 | 'r').read()
|
|---|
| 787 | indexes_sql = open(os.path.join(template_path, "sqlite3_indexes.sql"),
|
|---|
| 788 | 'r').read()
|
|---|
| 789 | else:
|
|---|
| 790 | # Set up the trigger that takes care of
|
|---|
| 791 | # the correct deletion of entries across the different tables
|
|---|
| 792 | delete_trigger_sql = open(os.path.join(template_path,
|
|---|
| 793 | "postgresql_delete_trigger.sql"),
|
|---|
| 794 | 'r').read()
|
|---|
| 795 | indexes_sql = open(os.path.join(template_path,
|
|---|
| 796 | "postgresql_indexes.sql"), 'r').read()
|
|---|
| 797 |
|
|---|
| 798 | # Connect now to the database
|
|---|
| 799 | if dbif.connected is not True:
|
|---|
| 800 | dbif.connect()
|
|---|
| 801 |
|
|---|
| 802 | # Execute the SQL statements for sqlite
|
|---|
| 803 | # Create the global tables for the native grass datatypes
|
|---|
| 804 | dbif.execute_transaction(raster_tables_sql)
|
|---|
| 805 | dbif.execute_transaction(raster_metadata_sql)
|
|---|
| 806 | dbif.execute_transaction(raster_views_sql)
|
|---|
| 807 | dbif.execute_transaction(vector_tables_sql)
|
|---|
| 808 | dbif.execute_transaction(vector_metadata_sql)
|
|---|
| 809 | dbif.execute_transaction(vector_views_sql)
|
|---|
| 810 | dbif.execute_transaction(raster3d_tables_sql)
|
|---|
| 811 | dbif.execute_transaction(raster3d_metadata_sql)
|
|---|
| 812 | dbif.execute_transaction(raster3d_views_sql)
|
|---|
| 813 | # Create the tables for the new space-time datatypes
|
|---|
| 814 | dbif.execute_transaction(strds_tables_sql)
|
|---|
| 815 | dbif.execute_transaction(strds_metadata_sql)
|
|---|
| 816 | dbif.execute_transaction(strds_views_sql)
|
|---|
| 817 | dbif.execute_transaction(stvds_tables_sql)
|
|---|
| 818 | dbif.execute_transaction(stvds_metadata_sql)
|
|---|
| 819 | dbif.execute_transaction(stvds_views_sql)
|
|---|
| 820 | dbif.execute_transaction(str3ds_tables_sql)
|
|---|
| 821 | dbif.execute_transaction(str3ds_metadata_sql)
|
|---|
| 822 | dbif.execute_transaction(str3ds_views_sql)
|
|---|
| 823 |
|
|---|
| 824 | # The delete trigger
|
|---|
| 825 | dbif.execute_transaction(delete_trigger_sql)
|
|---|
| 826 | # The indexes
|
|---|
| 827 | dbif.execute_transaction(indexes_sql)
|
|---|
| 828 |
|
|---|
| 829 | # Create the tgis metadata table to store the database
|
|---|
| 830 | # initial configuration
|
|---|
| 831 | # The metadata table content
|
|---|
| 832 | metadata = {}
|
|---|
| 833 | metadata["tgis_version"] = tgis_version
|
|---|
| 834 | metadata["tgis_db_version"] = tgis_db_version
|
|---|
| 835 | metadata["creation_time"] = datetime.today()
|
|---|
| 836 | _create_tgis_metadata_table(metadata, dbif)
|
|---|
| 837 |
|
|---|
| 838 | dbif.close()
|
|---|
| 839 |
|
|---|
| 840 | ###############################################################################
|
|---|
| 841 |
|
|---|
| 842 |
|
|---|
| 843 | def _create_tgis_metadata_table(content, dbif=None):
|
|---|
| 844 | """!Create the temporal gis metadata table which stores all metadata
|
|---|
| 845 | information about the temporal database.
|
|---|
| 846 |
|
|---|
| 847 | :param content: The dictionary that stores the key:value metadata
|
|---|
| 848 | that should be stored in the metadata table
|
|---|
| 849 | :param dbif: The database interface to be used
|
|---|
| 850 | """
|
|---|
| 851 | dbif, connected = init_dbif(dbif)
|
|---|
| 852 | statement = "CREATE TABLE tgis_metadata (key VARCHAR NOT NULL, value VARCHAR);\n";
|
|---|
| 853 | dbif.execute_transaction(statement)
|
|---|
| 854 |
|
|---|
| 855 | for key in content.keys():
|
|---|
| 856 | statement = "INSERT INTO tgis_metadata (key, value) VALUES " + \
|
|---|
| 857 | "(\'%s\' , \'%s\');\n" % (str(key), str(content[key]))
|
|---|
| 858 | dbif.execute_transaction(statement)
|
|---|
| 859 |
|
|---|
| 860 | if connected:
|
|---|
| 861 | dbif.close()
|
|---|
| 862 |
|
|---|
| 863 | ###############################################################################
|
|---|
| 864 |
|
|---|
| 865 |
|
|---|
| 866 | class SQLDatabaseInterfaceConnection(object):
|
|---|
| 867 | def __init__(self):
|
|---|
| 868 | self.tgis_mapsets = get_available_temporal_mapsets()
|
|---|
| 869 | self.current_mapset = get_current_mapset()
|
|---|
| 870 | self.connections = {}
|
|---|
| 871 | self.connected = False
|
|---|
| 872 |
|
|---|
| 873 | self.unique_connections = {}
|
|---|
| 874 |
|
|---|
| 875 | for mapset in self.tgis_mapsets.keys():
|
|---|
| 876 | driver, dbstring = self.tgis_mapsets[mapset]
|
|---|
| 877 |
|
|---|
| 878 | if dbstring not in self.unique_connections.keys():
|
|---|
| 879 | self.unique_connections[dbstring] = DBConnection(backend=driver,
|
|---|
| 880 | dbstring=dbstring)
|
|---|
| 881 |
|
|---|
| 882 | self.connections[mapset] = self.unique_connections[dbstring]
|
|---|
| 883 |
|
|---|
| 884 | self.msgr = get_tgis_message_interface()
|
|---|
| 885 |
|
|---|
| 886 | def get_dbmi(self, mapset=None):
|
|---|
| 887 | if mapset is None:
|
|---|
| 888 | mapset = self.current_mapset
|
|---|
| 889 | return self.connections[mapset].dbmi
|
|---|
| 890 |
|
|---|
| 891 | def rollback(self, mapset=None):
|
|---|
| 892 | """
|
|---|
| 893 | Roll back the last transaction. This must be called
|
|---|
| 894 | in case a new query should be performed after a db error.
|
|---|
| 895 |
|
|---|
| 896 | This is only relevant for postgresql database.
|
|---|
| 897 | """
|
|---|
| 898 | if mapset is None:
|
|---|
| 899 | mapset = self.current_mapset
|
|---|
| 900 |
|
|---|
| 901 | def connect(self):
|
|---|
| 902 | """Connect to the DBMI to execute SQL statements
|
|---|
| 903 |
|
|---|
| 904 | Supported backends are sqlite3 and postgresql
|
|---|
| 905 | """
|
|---|
| 906 | for mapset in self.tgis_mapsets.keys():
|
|---|
| 907 | driver, dbstring = self.tgis_mapsets[mapset]
|
|---|
| 908 | conn = self.connections[mapset]
|
|---|
| 909 | if conn.is_connected() is False:
|
|---|
| 910 | conn.connect(dbstring)
|
|---|
| 911 |
|
|---|
| 912 | self.connected = True
|
|---|
| 913 |
|
|---|
| 914 | def is_connected(self):
|
|---|
| 915 | return self.connected
|
|---|
| 916 |
|
|---|
| 917 | def close(self):
|
|---|
| 918 | """Close the DBMI connection
|
|---|
| 919 |
|
|---|
| 920 | There may be several temporal databases in a location, hence
|
|---|
| 921 | close all temporal databases that have been opened.
|
|---|
| 922 | """
|
|---|
| 923 | for key in self.unique_connections.keys():
|
|---|
| 924 | self.unique_connections[key].close()
|
|---|
| 925 |
|
|---|
| 926 | self.connected = False
|
|---|
| 927 |
|
|---|
| 928 | def mogrify_sql_statement(self, content, mapset=None):
|
|---|
| 929 | """Return the SQL statement and arguments as executable SQL string
|
|---|
| 930 |
|
|---|
| 931 | :param content: The content as tuple with two entries, the first
|
|---|
| 932 | entry is the SQL statement with DBMI specific
|
|---|
| 933 | place holder (?), the second entry is the argument
|
|---|
| 934 | list that should substitute the place holder.
|
|---|
| 935 | :param mapset: The mapset of the abstract dataset or temporal
|
|---|
| 936 | database location, if None the current mapset
|
|---|
| 937 | will be used
|
|---|
| 938 | """
|
|---|
| 939 | if mapset is None:
|
|---|
| 940 | mapset = self.current_mapset
|
|---|
| 941 |
|
|---|
| 942 | if mapset not in self.tgis_mapsets.keys():
|
|---|
| 943 | self.msgr.fatal(_("Unable to mogrify sql statement. " +
|
|---|
| 944 | self._create_mapset_error_message(mapset)))
|
|---|
| 945 |
|
|---|
| 946 | return self.connections[mapset].mogrify_sql_statement(content)
|
|---|
| 947 |
|
|---|
| 948 | def check_table(self, table_name, mapset=None):
|
|---|
| 949 | """Check if a table exists in the temporal database
|
|---|
| 950 |
|
|---|
| 951 | :param table_name: The name of the table to be checked for existence
|
|---|
| 952 | :param mapset: The mapset of the abstract dataset or temporal
|
|---|
| 953 | database location, if None the current mapset
|
|---|
| 954 | will be used
|
|---|
| 955 | :returns: True if the table exists, False otherwise
|
|---|
| 956 |
|
|---|
| 957 | TODO:
|
|---|
| 958 | There may be several temporal databases in a location, hence
|
|---|
| 959 | the mapset is used to query the correct temporal database.
|
|---|
| 960 | """
|
|---|
| 961 | if mapset is None:
|
|---|
| 962 | mapset = self.current_mapset
|
|---|
| 963 |
|
|---|
| 964 | if mapset not in self.tgis_mapsets.keys():
|
|---|
| 965 | self.msgr.fatal(_("Unable to check table. " +
|
|---|
| 966 | self._create_mapset_error_message(mapset)))
|
|---|
| 967 |
|
|---|
| 968 | return self.connections[mapset].check_table(table_name)
|
|---|
| 969 |
|
|---|
| 970 | def execute(self, statement, args=None, mapset=None):
|
|---|
| 971 | """
|
|---|
| 972 |
|
|---|
| 973 | :param mapset: The mapset of the abstract dataset or temporal
|
|---|
| 974 | database location, if None the current mapset
|
|---|
| 975 | will be used
|
|---|
| 976 | """
|
|---|
| 977 | if mapset is None:
|
|---|
| 978 | mapset = self.current_mapset
|
|---|
| 979 |
|
|---|
| 980 | if mapset not in self.tgis_mapsets.keys():
|
|---|
| 981 | self.msgr.fatal(_("Unable to execute sql statement. " +
|
|---|
| 982 | self._create_mapset_error_message(mapset)))
|
|---|
| 983 |
|
|---|
| 984 | return self.connections[mapset].execute(statement, args)
|
|---|
| 985 |
|
|---|
| 986 | def fetchone(self, mapset=None):
|
|---|
| 987 | if mapset is None:
|
|---|
| 988 | mapset = self.current_mapset
|
|---|
| 989 |
|
|---|
| 990 | if mapset not in self.tgis_mapsets.keys():
|
|---|
| 991 | self.msgr.fatal(_("Unable to fetch one. " +
|
|---|
| 992 | self._create_mapset_error_message(mapset)))
|
|---|
| 993 |
|
|---|
| 994 | return self.connections[mapset].fetchone()
|
|---|
| 995 |
|
|---|
| 996 | def fetchall(self, mapset=None):
|
|---|
| 997 | if mapset is None:
|
|---|
| 998 | mapset = self.current_mapset
|
|---|
| 999 |
|
|---|
| 1000 | if mapset not in self.tgis_mapsets.keys():
|
|---|
| 1001 | self.msgr.fatal(_("Unable to fetch all. " +
|
|---|
| 1002 | self._create_mapset_error_message(mapset)))
|
|---|
| 1003 |
|
|---|
| 1004 | return self.connections[mapset].fetchall()
|
|---|
| 1005 |
|
|---|
| 1006 | def execute_transaction(self, statement, mapset=None):
|
|---|
| 1007 | """Execute a transactional SQL statement
|
|---|
| 1008 |
|
|---|
| 1009 | The BEGIN and END TRANSACTION statements will be added automatically
|
|---|
| 1010 | to the sql statement
|
|---|
| 1011 |
|
|---|
| 1012 | :param statement: The executable SQL statement or SQL script
|
|---|
| 1013 | """
|
|---|
| 1014 | if mapset is None:
|
|---|
| 1015 | mapset = self.current_mapset
|
|---|
| 1016 |
|
|---|
| 1017 | if mapset not in self.tgis_mapsets.keys():
|
|---|
| 1018 | self.msgr.fatal(_("Unable to execute transaction. " +
|
|---|
| 1019 | self._create_mapset_error_message(mapset)))
|
|---|
| 1020 |
|
|---|
| 1021 | return self.connections[mapset].execute_transaction(statement)
|
|---|
| 1022 |
|
|---|
| 1023 | def _create_mapset_error_message(self, mapset):
|
|---|
| 1024 |
|
|---|
| 1025 | return("You have no permission to "
|
|---|
| 1026 | "access mapset <%(mapset)s>, or "
|
|---|
| 1027 | "mapset <%(mapset)s> has no temporal database. "
|
|---|
| 1028 | "Accessible mapsets are: <%(mapsets)s>" % \
|
|---|
| 1029 | {"mapset": mapset,
|
|---|
| 1030 | "mapsets":','.join(self.tgis_mapsets.keys())})
|
|---|
| 1031 |
|
|---|
| 1032 | ###############################################################################
|
|---|
| 1033 |
|
|---|
| 1034 |
|
|---|
| 1035 | class DBConnection(object):
|
|---|
| 1036 | """This class represents the database interface connection
|
|---|
| 1037 | and provides access to the chosen backend modules.
|
|---|
| 1038 |
|
|---|
| 1039 | The following DBMS are supported:
|
|---|
| 1040 |
|
|---|
| 1041 | - sqlite via the sqlite3 standard library
|
|---|
| 1042 | - postgresql via psycopg2
|
|---|
| 1043 | """
|
|---|
| 1044 |
|
|---|
| 1045 | def __init__(self, backend=None, dbstring=None):
|
|---|
| 1046 | """ Constructor of a database connection
|
|---|
| 1047 |
|
|---|
| 1048 | param backend:The database backend sqlite or pg
|
|---|
| 1049 | param dbstring: The database connection string
|
|---|
| 1050 | """
|
|---|
| 1051 | self.connected = False
|
|---|
| 1052 | if backend is None:
|
|---|
| 1053 | global tgis_backend
|
|---|
| 1054 | if tgis_backend == "sqlite":
|
|---|
| 1055 | self.dbmi = sqlite3
|
|---|
| 1056 | else:
|
|---|
| 1057 | self.dbmi = psycopg2
|
|---|
| 1058 | else:
|
|---|
| 1059 | if backend == "sqlite":
|
|---|
| 1060 | self.dbmi = sqlite3
|
|---|
| 1061 | else:
|
|---|
| 1062 | self.dbmi = psycopg2
|
|---|
| 1063 |
|
|---|
| 1064 | if dbstring is None:
|
|---|
| 1065 | global tgis_database_string
|
|---|
| 1066 | self.dbstring = tgis_database_string
|
|---|
| 1067 |
|
|---|
| 1068 | self.dbstring = dbstring
|
|---|
| 1069 |
|
|---|
| 1070 | self.msgr = get_tgis_message_interface()
|
|---|
| 1071 | self.msgr.debug(1, "DBConnection constructor:"\
|
|---|
| 1072 | "\n backend: %s"\
|
|---|
| 1073 | "\n dbstring: %s"%(backend, self.dbstring))
|
|---|
| 1074 | #"\n traceback:%s"%(backend, self.dbstring,
|
|---|
| 1075 | #str(" \n".join(traceback.format_stack()))))
|
|---|
| 1076 |
|
|---|
| 1077 | def __del__(self):
|
|---|
| 1078 | if self.connected is True:
|
|---|
| 1079 | self.close()
|
|---|
| 1080 |
|
|---|
| 1081 | def is_connected(self):
|
|---|
| 1082 | return self.connected
|
|---|
| 1083 |
|
|---|
| 1084 | def rollback(self):
|
|---|
| 1085 | """
|
|---|
| 1086 | Roll back the last transaction. This must be called
|
|---|
| 1087 | in case a new query should be performed after a db error.
|
|---|
| 1088 |
|
|---|
| 1089 | This is only relevant for postgresql database.
|
|---|
| 1090 | """
|
|---|
| 1091 | if self.dbmi.__name__ == "psycopg2":
|
|---|
| 1092 | if self.connected:
|
|---|
| 1093 | self.connection.rollback()
|
|---|
| 1094 |
|
|---|
| 1095 | def connect(self, dbstring=None):
|
|---|
| 1096 | """Connect to the DBMI to execute SQL statements
|
|---|
| 1097 |
|
|---|
| 1098 | Supported backends are sqlite3 and postgresql
|
|---|
| 1099 |
|
|---|
| 1100 | param dbstring: The database connection string
|
|---|
| 1101 | """
|
|---|
| 1102 | # Connection in the current mapset
|
|---|
| 1103 | if dbstring is None:
|
|---|
| 1104 | dbstring = self.dbstring
|
|---|
| 1105 | try:
|
|---|
| 1106 | if self.dbmi.__name__ == "sqlite3":
|
|---|
| 1107 | self.connection = self.dbmi.connect(dbstring,
|
|---|
| 1108 | detect_types=self.dbmi.PARSE_DECLTYPES | self.dbmi.PARSE_COLNAMES)
|
|---|
| 1109 | self.connection.row_factory = self.dbmi.Row
|
|---|
| 1110 | self.connection.isolation_level = None
|
|---|
| 1111 | self.cursor = self.connection.cursor()
|
|---|
| 1112 | self.cursor.execute("PRAGMA synchronous = OFF")
|
|---|
| 1113 | self.cursor.execute("PRAGMA journal_mode = MEMORY")
|
|---|
| 1114 | elif self.dbmi.__name__ == "psycopg2":
|
|---|
| 1115 | self.connection = self.dbmi.connect(dbstring)
|
|---|
| 1116 | #self.connection.set_isolation_level(dbmi.extensions.ISOLATION_LEVEL_AUTOCOMMIT)
|
|---|
| 1117 | self.cursor = self.connection.cursor(
|
|---|
| 1118 | cursor_factory=self.dbmi.extras.DictCursor)
|
|---|
| 1119 | self.connected = True
|
|---|
| 1120 | except Exception as e:
|
|---|
| 1121 | self.msgr.fatal(_("Unable to connect to %(db)s database: "
|
|---|
| 1122 | "%(string)s\nException: \"%(ex)s\"\nPlease use"
|
|---|
| 1123 | " t.connect to set a read- and writable "
|
|---|
| 1124 | "temporal database backend") % (
|
|---|
| 1125 | {"db": self.dbmi.__name__,
|
|---|
| 1126 | "string": tgis_database_string, "ex": e, }))
|
|---|
| 1127 |
|
|---|
| 1128 | def close(self):
|
|---|
| 1129 | """Close the DBMI connection
|
|---|
| 1130 | TODO:
|
|---|
| 1131 | There may be several temporal databases in a location, hence
|
|---|
| 1132 | close all temporal databases that have been opened. Use a dictionary
|
|---|
| 1133 | to manage different connections.
|
|---|
| 1134 | """
|
|---|
| 1135 | self.connection.commit()
|
|---|
| 1136 | self.cursor.close()
|
|---|
| 1137 | self.connected = False
|
|---|
| 1138 |
|
|---|
| 1139 | def mogrify_sql_statement(self, content):
|
|---|
| 1140 | """Return the SQL statement and arguments as executable SQL string
|
|---|
| 1141 |
|
|---|
| 1142 | TODO:
|
|---|
| 1143 | Use the mapset argument to identify the correct database driver
|
|---|
| 1144 |
|
|---|
| 1145 | :param content: The content as tuple with two entries, the first
|
|---|
| 1146 | entry is the SQL statement with DBMI specific
|
|---|
| 1147 | place holder (?), the second entry is the argument
|
|---|
| 1148 | list that should substitute the place holder.
|
|---|
| 1149 | :param mapset: The mapset of the abstract dataset or temporal
|
|---|
| 1150 | database location, if None the current mapset
|
|---|
| 1151 | will be used
|
|---|
| 1152 |
|
|---|
| 1153 | Usage:
|
|---|
| 1154 |
|
|---|
| 1155 | .. code-block:: python
|
|---|
| 1156 |
|
|---|
| 1157 | >>> init()
|
|---|
| 1158 | >>> dbif = SQLDatabaseInterfaceConnection()
|
|---|
| 1159 | >>> dbif.mogrify_sql_statement(["SELECT ctime FROM raster_base WHERE id = ?",
|
|---|
| 1160 | ... ["soil@PERMANENT",]])
|
|---|
| 1161 | "SELECT ctime FROM raster_base WHERE id = 'soil@PERMANENT'"
|
|---|
| 1162 |
|
|---|
| 1163 | """
|
|---|
| 1164 | sql = content[0]
|
|---|
| 1165 | args = content[1]
|
|---|
| 1166 |
|
|---|
| 1167 | if self.dbmi.__name__ == "psycopg2":
|
|---|
| 1168 | if len(args) == 0:
|
|---|
| 1169 | return sql
|
|---|
| 1170 | else:
|
|---|
| 1171 | if self.connected:
|
|---|
| 1172 | try:
|
|---|
| 1173 | return self.cursor.mogrify(sql, args)
|
|---|
| 1174 | except Exception as exc:
|
|---|
| 1175 | print(sql, args)
|
|---|
| 1176 | raise exc
|
|---|
| 1177 | else:
|
|---|
| 1178 | self.connect()
|
|---|
| 1179 | statement = self.cursor.mogrify(sql, args)
|
|---|
| 1180 | self.close()
|
|---|
| 1181 | return statement
|
|---|
| 1182 |
|
|---|
| 1183 | elif self.dbmi.__name__ == "sqlite3":
|
|---|
| 1184 | if len(args) == 0:
|
|---|
| 1185 | return sql
|
|---|
| 1186 | else:
|
|---|
| 1187 | # Unfortunately as sqlite does not support
|
|---|
| 1188 | # the transformation of sql strings and qmarked or
|
|---|
| 1189 | # named arguments we must make our hands dirty
|
|---|
| 1190 | # and do it by ourself. :(
|
|---|
| 1191 | # Doors are open for SQL injection because of the
|
|---|
| 1192 | # limited python sqlite3 implementation!!!
|
|---|
| 1193 | pos = 0
|
|---|
| 1194 | count = 0
|
|---|
| 1195 | maxcount = 100
|
|---|
| 1196 | statement = sql
|
|---|
| 1197 |
|
|---|
| 1198 | while count < maxcount:
|
|---|
| 1199 | pos = statement.find("?", pos + 1)
|
|---|
| 1200 | if pos == -1:
|
|---|
| 1201 | break
|
|---|
| 1202 |
|
|---|
| 1203 | if args[count] is None:
|
|---|
| 1204 | statement = "%sNULL%s" % (statement[0:pos],
|
|---|
| 1205 | statement[pos + 1:])
|
|---|
| 1206 | elif isinstance(args[count], (int, long)):
|
|---|
| 1207 | statement = "%s%d%s" % (statement[0:pos], args[count],
|
|---|
| 1208 | statement[pos + 1:])
|
|---|
| 1209 | elif isinstance(args[count], float):
|
|---|
| 1210 | statement = "%s%f%s" % (statement[0:pos], args[count],
|
|---|
| 1211 | statement[pos + 1:])
|
|---|
| 1212 | else:
|
|---|
| 1213 | # Default is a string, this works for datetime
|
|---|
| 1214 | # objects too
|
|---|
| 1215 | statement = "%s\'%s\'%s" % (statement[0:pos],
|
|---|
| 1216 | str(args[count]),
|
|---|
| 1217 | statement[pos + 1:])
|
|---|
| 1218 | count += 1
|
|---|
| 1219 |
|
|---|
| 1220 | return statement
|
|---|
| 1221 |
|
|---|
| 1222 | def check_table(self, table_name):
|
|---|
| 1223 | """Check if a table exists in the temporal database
|
|---|
| 1224 |
|
|---|
| 1225 | :param table_name: The name of the table to be checked for existence
|
|---|
| 1226 | :param mapset: The mapset of the abstract dataset or temporal
|
|---|
| 1227 | database location, if None the current mapset
|
|---|
| 1228 | will be used
|
|---|
| 1229 | :returns: True if the table exists, False otherwise
|
|---|
| 1230 |
|
|---|
| 1231 | TODO:
|
|---|
| 1232 | There may be several temporal databases in a location, hence
|
|---|
| 1233 | the mapset is used to query the correct temporal database.
|
|---|
| 1234 | """
|
|---|
| 1235 | table_exists = False
|
|---|
| 1236 | connected = False
|
|---|
| 1237 | if not self.connected:
|
|---|
| 1238 | self.connect()
|
|---|
| 1239 | connected = True
|
|---|
| 1240 |
|
|---|
| 1241 | # Check if the database already exists
|
|---|
| 1242 | if self.dbmi.__name__ == "sqlite3":
|
|---|
| 1243 |
|
|---|
| 1244 | self.cursor.execute("SELECT name FROM sqlite_master WHERE "
|
|---|
| 1245 | "type='table' AND name='%s';" % table_name)
|
|---|
| 1246 | name = self.cursor.fetchone()
|
|---|
| 1247 | if name and name[0] == table_name:
|
|---|
| 1248 | table_exists = True
|
|---|
| 1249 | else:
|
|---|
| 1250 | # Check for raster_base table
|
|---|
| 1251 | self.cursor.execute("SELECT EXISTS(SELECT * FROM information_schema.tables "
|
|---|
| 1252 | "WHERE table_name=%s)", ('%s' % table_name,))
|
|---|
| 1253 | if self.cursor.fetchone()[0]:
|
|---|
| 1254 | table_exists = True
|
|---|
| 1255 |
|
|---|
| 1256 | if connected:
|
|---|
| 1257 | self.close()
|
|---|
| 1258 |
|
|---|
| 1259 | return table_exists
|
|---|
| 1260 |
|
|---|
| 1261 | def execute(self, statement, args=None):
|
|---|
| 1262 | """Execute a SQL statement
|
|---|
| 1263 |
|
|---|
| 1264 | :param statement: The executable SQL statement or SQL script
|
|---|
| 1265 | """
|
|---|
| 1266 | connected = False
|
|---|
| 1267 | if not self.connected:
|
|---|
| 1268 | self.connect()
|
|---|
| 1269 | connected = True
|
|---|
| 1270 | try:
|
|---|
| 1271 | if args:
|
|---|
| 1272 | self.cursor.execute(statement, args)
|
|---|
| 1273 | else:
|
|---|
| 1274 | self.cursor.execute(statement)
|
|---|
| 1275 | except:
|
|---|
| 1276 | if connected:
|
|---|
| 1277 | self.close()
|
|---|
| 1278 | self.msgr.error(_("Unable to execute :\n %(sql)s" %
|
|---|
| 1279 | {"sql": statement}))
|
|---|
| 1280 | raise
|
|---|
| 1281 |
|
|---|
| 1282 | if connected:
|
|---|
| 1283 | self.close()
|
|---|
| 1284 |
|
|---|
| 1285 | def fetchone(self):
|
|---|
| 1286 | if self.connected:
|
|---|
| 1287 | return self.cursor.fetchone()
|
|---|
| 1288 | return None
|
|---|
| 1289 |
|
|---|
| 1290 | def fetchall(self):
|
|---|
| 1291 | if self.connected:
|
|---|
| 1292 | return self.cursor.fetchall()
|
|---|
| 1293 | return None
|
|---|
| 1294 |
|
|---|
| 1295 | def execute_transaction(self, statement, mapset=None):
|
|---|
| 1296 | """Execute a transactional SQL statement
|
|---|
| 1297 |
|
|---|
| 1298 | The BEGIN and END TRANSACTION statements will be added automatically
|
|---|
| 1299 | to the sql statement
|
|---|
| 1300 |
|
|---|
| 1301 | :param statement: The executable SQL statement or SQL script
|
|---|
| 1302 | """
|
|---|
| 1303 | connected = False
|
|---|
| 1304 | if not self.connected:
|
|---|
| 1305 | self.connect()
|
|---|
| 1306 | connected = True
|
|---|
| 1307 |
|
|---|
| 1308 | sql_script = ""
|
|---|
| 1309 | sql_script += "BEGIN TRANSACTION;\n"
|
|---|
| 1310 | sql_script += statement
|
|---|
| 1311 | sql_script += "END TRANSACTION;"
|
|---|
| 1312 |
|
|---|
| 1313 | try:
|
|---|
| 1314 | if self.dbmi.__name__ == "sqlite3":
|
|---|
| 1315 | self.cursor.executescript(statement)
|
|---|
| 1316 | else:
|
|---|
| 1317 | self.cursor.execute(statement)
|
|---|
| 1318 | self.connection.commit()
|
|---|
| 1319 | except:
|
|---|
| 1320 | if connected:
|
|---|
| 1321 | self.close()
|
|---|
| 1322 | self.msgr.error(_("Unable to execute transaction:\n %(sql)s" %
|
|---|
| 1323 | {"sql": statement}))
|
|---|
| 1324 | raise
|
|---|
| 1325 |
|
|---|
| 1326 | if connected:
|
|---|
| 1327 | self.close()
|
|---|
| 1328 |
|
|---|
| 1329 | ###############################################################################
|
|---|
| 1330 |
|
|---|
| 1331 |
|
|---|
| 1332 | def init_dbif(dbif):
|
|---|
| 1333 | """This method checks if the database interface connection exists,
|
|---|
| 1334 | if not a new one will be created, connected and True will be returned.
|
|---|
| 1335 | If the database interface exists but is connected, the connection will
|
|---|
| 1336 | be established.
|
|---|
| 1337 |
|
|---|
| 1338 | :returns: the tuple (dbif, True|False)
|
|---|
| 1339 |
|
|---|
| 1340 | Usage code sample:
|
|---|
| 1341 |
|
|---|
| 1342 | .. code-block:: python
|
|---|
| 1343 |
|
|---|
| 1344 | dbif, connect = tgis.init_dbif(None)
|
|---|
| 1345 |
|
|---|
| 1346 | sql = dbif.mogrify_sql_statement(["SELECT * FROM raster_base WHERE ? = ?"],
|
|---|
| 1347 | ["id", "soil@PERMANENT"])
|
|---|
| 1348 | dbif.execute_transaction(sql)
|
|---|
| 1349 |
|
|---|
| 1350 | if connect:
|
|---|
| 1351 | dbif.close()
|
|---|
| 1352 |
|
|---|
| 1353 | """
|
|---|
| 1354 | if dbif is None:
|
|---|
| 1355 | dbif = SQLDatabaseInterfaceConnection()
|
|---|
| 1356 | dbif.connect()
|
|---|
| 1357 | return dbif, True
|
|---|
| 1358 | elif dbif.is_connected() is False:
|
|---|
| 1359 | dbif.connect()
|
|---|
| 1360 | return dbif, True
|
|---|
| 1361 |
|
|---|
| 1362 | return dbif, False
|
|---|
| 1363 |
|
|---|
| 1364 | ###############################################################################
|
|---|
| 1365 |
|
|---|
| 1366 | if __name__ == "__main__":
|
|---|
| 1367 | import doctest
|
|---|
| 1368 | doctest.testmod()
|
|---|
