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GeezerVison is showing github.com — sqlobject/sqlobject/joins.py at master · sqlobject/sqlobject Expand file tree/ Copy pathjoins.pyMore file actions 656 lines (531 loc) · 20.4 KB / Copy pathjoins.pyFile metadata and controls656 lines (531 loc) · 20.4 KB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 from itertools import count from . import boundattributes from . import classregistry from . import events from . import sresults from . import styles from . import sqlbuilder from .styles import capword __all__ = ['MultipleJoin', 'SQLMultipleJoin', 'RelatedJoin', 'SQLRelatedJoin', 'SingleJoin', 'ManyToMany', 'OneToMany'] creationOrder = count() NoDefault = sqlbuilder.NoDefault def getID(obj): try: return obj.id except AttributeError: return int(obj) class Join(object): def __init__(self, otherClass=None, **kw): kw['otherClass'] = otherClass self.kw = kw self._joinMethodName = self.kw.pop('joinMethodName', None) self.creationOrder = next(creationOrder) def _set_joinMethodName(self, value): assert self._joinMethodName == value or self._joinMethodName is None, \ "You have already given an explicit joinMethodName (%s), " \ "and you are now setting it to %s" % (self._joinMethodName, value) self._joinMethodName = value def _get_joinMethodName(self): return self._joinMethodName joinMethodName = property(_get_joinMethodName, _set_joinMethodName) name = joinMethodName def withClass(self, soClass): if 'joinMethodName' in self.kw: self._joinMethodName = self.kw['joinMethodName'] del self.kw['joinMethodName'] return self.baseClass(creationOrder=self.creationOrder, soClass=soClass, joinDef=self, joinMethodName=self._joinMethodName, **self.kw) # A join is separate from a foreign key, i.e., it is # many-to-many, or one-to-many where the *other* class # has the foreign key. class SOJoin(object): def __init__(self, creationOrder, soClass=None, otherClass=None, joinColumn=None, joinMethodName=None, orderBy=NoDefault, joinDef=None): self.creationOrder = creationOrder self.soClass = soClass self.joinDef = joinDef self.otherClassName = otherClass classregistry.registry(soClass.sqlmeta.registry).addClassCallback( otherClass, self._setOtherClass) self.joinColumn = joinColumn self.joinMethodName = joinMethodName self._orderBy = orderBy if not self.joinColumn: # Here we set up the basic join, which is # one-to-many, where the other class points to # us. self.joinColumn = styles.getStyle( self.soClass).tableReference(self.soClass.sqlmeta.table) def orderBy(self): if self._orderBy is NoDefault: self._orderBy = self.otherClass.sqlmeta.defaultOrder return self._orderBy orderBy = property(orderBy) def _setOtherClass(self, cls): self.otherClass = cls def hasIntermediateTable(self): return False def _applyOrderBy(self, results, defaultSortClass): if self.orderBy is not None: doSort(results, self.orderBy) return results class MinType(object): """Sort less than everything, for handling None's in the results""" # functools.total_ordering would simplify this def __lt__(self, other): if self is other: return False return True def __eq__(self, other): return self is other def __gt__(self, other): return False def __le__(self, other): return True def __ge__(self, other): if self is other: return True return False Min = MinType() def doSort(results, orderBy): if isinstance(orderBy, (tuple, list)): if len(orderBy) == 1: orderBy = orderBy[0] else: # Rely on stable sort results, since this is simpler # than trying to munge everything into a single sort key doSort(results, orderBy[0]) doSort(results, orderBy[1:]) return if isinstance(orderBy, sqlbuilder.DESC) \ and isinstance(orderBy.expr, sqlbuilder.SQLObjectField): orderBy = '-' + orderBy.expr.original elif isinstance(orderBy, sqlbuilder.SQLObjectField): orderBy = orderBy.original # @@: but we don't handle more complex expressions for orderings if orderBy.startswith('-'): orderBy = orderBy[1:] reverse = True else: reverse = False def sortkey(x, attr=orderBy): a = getattr(x, attr) if a is None: return Min return a results.sort(key=sortkey, reverse=reverse) # This is a one-to-many class SOMultipleJoin(SOJoin): def __init__(self, addRemoveName=None, **kw): # addRemovePrefix is something like @@ SOJoin.__init__(self, **kw) # Here we generate the method names if not self.joinMethodName: name = self.otherClassName[0].lower() + self.otherClassName[1:] if name.endswith('s'): name += "es" else: name += "s" self.joinMethodName = name if addRemoveName: self.addRemoveName = addRemoveName else: self.addRemoveName = capword(self.otherClassName) def performJoin(self, inst): ids = inst._connection._SO_selectJoin( self.otherClass, self.joinColumn, inst.id) if inst.sqlmeta._perConnection: conn = inst._connection else: conn = None return self._applyOrderBy( [self.otherClass.get(id, conn) for (id,) in ids if id is not None], self.otherClass) def _dbNameToPythonName(self): for column in self.otherClass.sqlmeta.columns.values(): if column.dbName == self.joinColumn: return column.name return self.soClass.sqlmeta.style.dbColumnToPythonAttr(self.joinColumn) class MultipleJoin(Join): baseClass = SOMultipleJoin class SOSQLMultipleJoin(SOMultipleJoin): def performJoin(self, inst): if inst.sqlmeta._perConnection: conn = inst._connection else: conn = None pythonColumn = self._dbNameToPythonName() results = self.otherClass.select( getattr(self.otherClass.q, pythonColumn) == inst.id, connection=conn) return results.orderBy(self.orderBy) class SQLMultipleJoin(Join): baseClass = SOSQLMultipleJoin # This is a many-to-many join, with an intermediary table class SORelatedJoin(SOMultipleJoin): def __init__(self, otherColumn=None, intermediateTable=None, createRelatedTable=True, **kw): self.intermediateTable = intermediateTable self.otherColumn = otherColumn self.createRelatedTable = createRelatedTable SOMultipleJoin.__init__(self, **kw) classregistry.registry( self.soClass.sqlmeta.registry).addClassCallback( self.otherClassName, self._setOtherRelatedClass) def _setOtherRelatedClass(self, otherClass): if not self.intermediateTable: names = [self.soClass.sqlmeta.table, otherClass.sqlmeta.table] names.sort() self.intermediateTable = '%s_%s' % (names[0], names[1]) if not self.otherColumn: self.otherColumn = self.soClass.sqlmeta.style.tableReference( otherClass.sqlmeta.table) def hasIntermediateTable(self): return True def performJoin(self, inst): ids = inst._connection._SO_intermediateJoin( self.intermediateTable, self.otherColumn, self.joinColumn, inst.id) if inst.sqlmeta._perConnection: conn = inst._connection else: conn = None return self._applyOrderBy( [self.otherClass.get(id, conn) for (id,) in ids if id is not None], self.otherClass) def remove(self, inst, other): inst._connection._SO_intermediateDelete( self.intermediateTable, self.joinColumn, getID(inst), self.otherColumn, getID(other)) def add(self, inst, other): inst._connection._SO_intermediateInsert( self.intermediateTable, self.joinColumn, getID(inst), self.otherColumn, getID(other)) class RelatedJoin(MultipleJoin): baseClass = SORelatedJoin # helper classes to SQLRelatedJoin class OtherTableToJoin(sqlbuilder.SQLExpression): def __init__(self, otherTable, otherIdName, interTable, joinColumn, alias): self.otherTable = otherTable self.otherIdName = otherIdName self.interTable = interTable self.joinColumn = joinColumn self.alias = alias def tablesUsedImmediate(self): return [ '%s %s' % (self.otherTable, self.alias) if self.alias else self.otherTable, self.interTable, ] def __sqlrepr__(self, db): return '%s.%s = %s.%s' % ( self.alias if self.alias else self.otherTable, self.otherIdName, self.interTable, self.joinColumn) class JoinToTable(sqlbuilder.SQLExpression): def __init__(self, table, idName, interTable, joinColumn, alias): self.table = table self.idName = idName self.interTable = interTable self.joinColumn = joinColumn self.alias = alias def tablesUsedImmediate(self): return [ '%s %s' % (self.table, self.alias) if self.alias else self.table, self.interTable, ] def __sqlrepr__(self, db): return '%s.%s = %s.%s' % ( self.interTable, self.joinColumn, self.alias if self.alias else self.table, self.idName) class TableToId(sqlbuilder.SQLExpression): def __init__(self, table, idName, idValue, alias): self.table = table self.idName = idName self.idValue = idValue self.alias = alias def tablesUsedImmediate(self): return [ '%s %s' % (self.table, self.alias) if self.alias else self.table, ] def __sqlrepr__(self, db): return '%s.%s = %s' % ( self.alias if self.alias else self.table, self.idName, self.idValue) class SQLJoinSelectResults(sresults.SelectResults): def filter(self, filter_clause): clause_tables = filter_clause.tablesUsed(None) if self._SOSQLRelatedJoin_realSourceClass.sqlmeta.table \ in clause_tables: tableClass = self._SOSQLRelatedJoin_realSourceClass.__name__ raise ValueError( "Using table '%s' in the filter expression without an alias " "could produce wrong SQL. Most probably you need " "Alias(%s, '_SO_SQLRelatedJoin_OtherTable') instead." % (tableClass, tableClass) ) return sresults.SelectResults.filter(self, filter_clause) class SOSQLRelatedJoin(SORelatedJoin): def performJoin(self, inst): if inst.sqlmeta._perConnection: conn = inst._connection else: conn = None needAlias = self.soClass is self.otherClass if needAlias: source = sqlbuilder.Alias( self.otherClass, '_SO_SQLRelatedJoin_OtherTable') sresultsClass = SQLJoinSelectResults else: source = self.otherClass sresultsClass = self.otherClass.SelectResultsClass results = sresultsClass( source, sqlbuilder.AND( OtherTableToJoin( self.otherClass.sqlmeta.table, self.otherClass.sqlmeta.idName, self.intermediateTable, self.otherColumn, '_SO_SQLRelatedJoin_OtherTable' if needAlias else '', ), JoinToTable( self.soClass.sqlmeta.table, self.soClass.sqlmeta.idName, self.intermediateTable, self.joinColumn, '_SO_SQLRelatedJoin_ThisTable' if needAlias else '', ), TableToId( self.soClass.sqlmeta.table, self.soClass.sqlmeta.idName, inst.id, '_SO_SQLRelatedJoin_ThisTable' if needAlias else '', ), ), clauseTables=( '%s _SO_SQLRelatedJoin_ThisTable' % self.soClass.sqlmeta.table if needAlias else self.soClass.sqlmeta.table, '%s _SO_SQLRelatedJoin_OtherTable' % self.otherClass.sqlmeta.table if needAlias else self.otherClass.sqlmeta.table, self.intermediateTable, ), connection=conn, orderBy=self.orderBy, ) results._SOSQLRelatedJoin_realSourceClass = self.otherClass return results class SQLRelatedJoin(RelatedJoin): baseClass = SOSQLRelatedJoin class SOSingleJoin(SOMultipleJoin): def __init__(self, **kw): self.makeDefault = kw.pop('makeDefault', False) SOMultipleJoin.__init__(self, **kw) def performJoin(self, inst): if inst.sqlmeta._perConnection: conn = inst._connection else: conn = None pythonColumn = self._dbNameToPythonName() results = self.otherClass.select( getattr(self.otherClass.q, pythonColumn) == inst.id, connection=conn ) if results.count() == 0: if not self.makeDefault: return None else: kw = {self.soClass.sqlmeta.style. instanceIDAttrToAttr(pythonColumn): inst} # instanciating the otherClass with all return self.otherClass(**kw) else: return results[0] class SingleJoin(Join): baseClass = SOSingleJoin class SOManyToMany(object): def __init__(self, soClass, name, join, intermediateTable, joinColumn, otherColumn, createJoinTable, **attrs): self.name = name self.intermediateTable = intermediateTable self.joinColumn = joinColumn self.otherColumn = otherColumn self.createJoinTable = createJoinTable self.soClass = self.otherClass = None for name, value in attrs.items(): setattr(self, name, value) classregistry.registry( soClass.sqlmeta.registry).addClassCallback( join, self._setOtherClass) classregistry.registry( soClass.sqlmeta.registry).addClassCallback( soClass.__name__, self._setThisClass) def _setThisClass(self, soClass): self.soClass = soClass if self.soClass and self.otherClass: self._finishSet() def _setOtherClass(self, otherClass): self.otherClass = otherClass if self.soClass and self.otherClass: self._finishSet() def _finishSet(self): if self.intermediateTable is None: names = [self.soClass.sqlmeta.table, self.otherClass.sqlmeta.table] names.sort() self.intermediateTable = '%s_%s' % (names[0], names[1]) if not self.otherColumn: self.otherColumn = self.soClass.sqlmeta.style.tableReference( self.otherClass.sqlmeta.table) if not self.joinColumn: self.joinColumn = styles.getStyle( self.soClass).tableReference(self.soClass.sqlmeta.table) events.listen(self.event_CreateTableSignal, self.soClass, events.CreateTableSignal) events.listen(self.event_CreateTableSignal, self.otherClass, events.CreateTableSignal) self.clause = ( (self.otherClass.q.id == sqlbuilder.Field(self.intermediateTable, self.otherColumn)) & (sqlbuilder.Field(self.intermediateTable, self.joinColumn) == self.soClass.q.id)) def __get__(self, obj, type): if obj is None: return self query = ( (self.otherClass.q.id == sqlbuilder.Field(self.intermediateTable, self.otherColumn)) & (sqlbuilder.Field(self.intermediateTable, self.joinColumn) == obj.id)) select = self.otherClass.select(query) return _ManyToManySelectWrapper(obj, self, select) def event_CreateTableSignal(self, soClass, connection, extra_sql, post_funcs): if self.createJoinTable: post_funcs.append(self.event_CreateTableSignalPost) def event_CreateTableSignalPost(self, soClass, connection): if connection.tableExists(self.intermediateTable): return connection._SO_createJoinTable(self) class ManyToMany(boundattributes.BoundFactory): factory_class = SOManyToMany __restrict_attributes__ = ( 'join', 'intermediateTable', 'joinColumn', 'otherColumn', 'createJoinTable') __unpackargs__ = ('join',) # Default values: intermediateTable = None joinColumn = None otherColumn = None createJoinTable = True class _ManyToManySelectWrapper(object): def __init__(self, forObject, join, select): self.forObject = forObject self.join = join self.select = select def __getattr__(self, attr): # @@: This passes through private variable access too... should it? # Also magic methods, like __str__ return getattr(self.select, attr) def __repr__(self): return '<%s for: %s>' % (self.__class__.__name__, repr(self.select)) def __str__(self): return str(self.select) def __iter__(self): return iter(self.select) def __getitem__(self, key): return self.select[key] def add(self, obj): obj._connection._SO_intermediateInsert( self.join.intermediateTable, self.join.joinColumn, getID(self.forObject), self.join.otherColumn, getID(obj)) def remove(self, obj): obj._connection._SO_intermediateDelete( self.join.intermediateTable, self.join.joinColumn, getID(self.forObject), self.join.otherColumn, getID(obj)) def create(self, **kw): obj = self.join.otherClass(**kw) self.add(obj) return obj class SOOneToMany(object): def __init__(self, soClass, name, join, joinColumn, **attrs): self.soClass = soClass self.name = name self.joinColumn = joinColumn for name, value in attrs.items(): setattr(self, name, value) classregistry.registry( soClass.sqlmeta.registry).addClassCallback( join, self._setOtherClass) def _setOtherClass(self, otherClass): self.otherClass = otherClass if not self.joinColumn: self.joinColumn = styles.getStyle( self.soClass).tableReference(self.soClass.sqlmeta.table) self.clause = ( sqlbuilder.Field(self.otherClass.sqlmeta.table, self.joinColumn) == self.soClass.q.id) def __get__(self, obj, type): if obj is None: return self query = ( sqlbuilder.Field(self.otherClass.sqlmeta.table, self.joinColumn) == obj.id) select = self.otherClass.select(query) return _OneToManySelectWrapper(obj, self, select) class OneToMany(boundattributes.BoundFactory): factory_class = SOOneToMany __restrict_attributes__ = ( 'join', 'joinColumn') __unpackargs__ = ('join',) # Default values: joinColumn = None class _OneToManySelectWrapper(object): def __init__(self, forObject, join, select): self.forObject = forObject self.join = join self.select = select def __getattr__(self, attr): # @@: This passes through private variable access too... should it? # Also magic methods, like __str__ return getattr(self.select, attr) def __repr__(self): return '<%s for: %s>' % (self.__class__.__name__, repr(self.select)) def __str__(self): return str(self.select) def __iter__(self): return iter(self.select) def __getitem__(self, key): return self.select[key] def create(self, **kw): kw[self.join.joinColumn] = self.forObject.id return self.join.otherClass(**kw) |
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