root / env / lib / python2.7 / site-packages / south / db / oracle.py @ d1a4905f
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import os.path |
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import sys |
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import re |
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import warnings |
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import cx_Oracle |
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from django.db import connection, models |
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from django.db.backends.util import truncate_name |
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from django.core.management.color import no_style |
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from django.db.models.fields import NOT_PROVIDED |
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from django.db.utils import DatabaseError |
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# In revision r16016 function get_sequence_name has been transformed into
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# method of DatabaseOperations class. To make code backward-compatible we
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# need to handle both situations.
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try:
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from django.db.backends.oracle.base import get_sequence_name\ |
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as original_get_sequence_name
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except ImportError: |
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original_get_sequence_name = None
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from south.db import generic |
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warnings.warn("! WARNING: South's Oracle support is still alpha. "
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"Be wary of possible bugs.")
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class DatabaseOperations(generic.DatabaseOperations): |
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"""
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Oracle implementation of database operations.
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"""
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backend_name = 'oracle'
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alter_string_set_type = 'ALTER TABLE %(table_name)s MODIFY %(column)s %(type)s %(nullity)s;'
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alter_string_set_default = 'ALTER TABLE %(table_name)s MODIFY %(column)s DEFAULT %(default)s;'
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add_column_string = 'ALTER TABLE %s ADD %s;'
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delete_column_string = 'ALTER TABLE %s DROP COLUMN %s;'
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add_constraint_string = 'ALTER TABLE %(table_name)s ADD CONSTRAINT %(constraint)s %(clause)s'
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allows_combined_alters = False
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has_booleans = False
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constraints_dict = { |
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'P': 'PRIMARY KEY', |
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'U': 'UNIQUE', |
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'C': 'CHECK', |
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'R': 'FOREIGN KEY' |
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} |
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def get_sequence_name(self, table_name): |
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if original_get_sequence_name is None: |
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return self._get_connection().ops._get_sequence_name(table_name) |
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else:
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return original_get_sequence_name(table_name)
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#TODO: This will cause very obscure bugs if anyone uses a column name or string value
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# that looks like a column definition (with 'CHECK', 'DEFAULT' and/or 'NULL' in it)
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# e.g. "CHECK MATE" varchar(10) DEFAULT 'NULL'
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def adj_column_sql(self, col): |
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# Syntax fixes -- Oracle is picky about clause order
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col = re.sub('(?P<constr>CHECK \(.*\))(?P<any>.*)(?P<default>DEFAULT \d+)',
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lambda mo: '%s %s%s'%(mo.group('default'), mo.group('constr'), mo.group('any')), col) #syntax fix for boolean/integer field only |
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col = re.sub('(?P<not_null>(NOT )?NULL) (?P<misc>(.* )?)(?P<default>DEFAULT.+)',
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lambda mo: '%s %s %s'%(mo.group('default'),mo.group('not_null'),mo.group('misc') or ''), col) #fix order of NULL/NOT NULL and DEFAULT |
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return col
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def check_meta(self, table_name): |
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return table_name in [ m._meta.db_table for m in models.get_models() ] #caching provided by Django |
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def normalize_name(self, name): |
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"""
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Get the properly shortened and uppercased identifier as returned by quote_name(), but without the actual quotes.
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"""
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nn = self.quote_name(name)
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if nn[0] == '"' and nn[-1] == '"': |
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nn = nn[1:-1] |
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return nn
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@generic.invalidate_table_constraints
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def create_table(self, table_name, fields): |
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qn = self.quote_name(table_name)
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columns = [] |
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autoinc_sql = ''
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for field_name, field in fields: |
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col = self.column_sql(table_name, field_name, field)
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if not col: |
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continue
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col = self.adj_column_sql(col)
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columns.append(col) |
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if isinstance(field, models.AutoField): |
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autoinc_sql = connection.ops.autoinc_sql(table_name, field_name) |
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sql = 'CREATE TABLE %s (%s);' % (qn, ', '.join([col for col in columns])) |
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self.execute(sql)
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if autoinc_sql:
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self.execute(autoinc_sql[0]) |
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self.execute(autoinc_sql[1]) |
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@generic.invalidate_table_constraints
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def delete_table(self, table_name, cascade=True): |
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qn = self.quote_name(table_name)
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# Note: PURGE is not valid syntax for Oracle 9i (it was added in 10)
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if cascade:
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self.execute('DROP TABLE %s CASCADE CONSTRAINTS;' % qn) |
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else:
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self.execute('DROP TABLE %s;' % qn) |
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# If the table has an AutoField a sequence was created.
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sequence_sql = """
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DECLARE
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i INTEGER;
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BEGIN
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SELECT COUNT(*) INTO i FROM USER_CATALOG
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WHERE TABLE_NAME = '%(sq_name)s' AND TABLE_TYPE = 'SEQUENCE';
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IF i = 1 THEN
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EXECUTE IMMEDIATE 'DROP SEQUENCE "%(sq_name)s"';
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END IF;
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END;
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/""" % {'sq_name': self.get_sequence_name(table_name)} |
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self.execute(sequence_sql)
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@generic.invalidate_table_constraints
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def alter_column(self, table_name, name, field, explicit_name=True): |
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if self.dry_run: |
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if self.debug: |
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print ' - no dry run output for alter_column() due to dynamic DDL, sorry' |
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return
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qn = self.quote_name(table_name)
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# hook for the field to do any resolution prior to it's attributes being queried
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if hasattr(field, 'south_init'): |
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field.south_init() |
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field = self._field_sanity(field)
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# Add _id or whatever if we need to
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field.set_attributes_from_name(name) |
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if not explicit_name: |
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name = field.column |
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qn_col = self.quote_name(name)
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# First, change the type
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# This will actually also add any CHECK constraints needed,
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# since e.g. 'type' for a BooleanField is 'NUMBER(1) CHECK (%(qn_column)s IN (0,1))'
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params = { |
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'table_name':qn,
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'column': qn_col,
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'type': self._db_type_for_alter_column(field), |
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'nullity': 'NOT NULL', |
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'default': 'NULL' |
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} |
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if field.null:
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params['nullity'] = 'NULL' |
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if not field.null and field.has_default(): |
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params['default'] = self._default_value_workaround(field.get_default()) |
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sql_templates = [ |
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(self.alter_string_set_type, params),
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(self.alter_string_set_default, params.copy()),
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] |
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# drop CHECK constraints. Make sure this is executed before the ALTER TABLE statements
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# generated above, since those statements recreate the constraints we delete here.
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check_constraints = self._constraints_affecting_columns(table_name, [name], "CHECK") |
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for constraint in check_constraints: |
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self.execute(self.delete_check_sql % { |
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'table': self.quote_name(table_name), |
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'constraint': self.quote_name(constraint), |
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}) |
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for sql_template, params in sql_templates: |
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try:
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self.execute(sql_template % params)
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except DatabaseError, exc:
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description = str(exc)
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# Oracle complains if a column is already NULL/NOT NULL
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if 'ORA-01442' in description or 'ORA-01451' in description: |
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# so we just drop NULL/NOT NULL part from target sql and retry
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params['nullity'] = '' |
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sql = sql_template % params |
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self.execute(sql)
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# Oracle also has issues if we try to change a regular column
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# to a LOB or vice versa (also REF, object, VARRAY or nested
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# table, but these don't come up much in Django apps)
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elif 'ORA-22858' in description or 'ORA-22859' in description: |
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self._alter_column_lob_workaround(table_name, name, field)
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else:
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raise
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def _alter_column_lob_workaround(self, table_name, name, field): |
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"""
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Oracle refuses to change a column type from/to LOB to/from a regular
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column. In Django, this shows up when the field is changed from/to
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a TextField.
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What we need to do instead is:
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- Rename the original column
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- Add the desired field as new
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- Update the table to transfer values from old to new
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- Drop old column
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"""
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renamed = self._generate_temp_name(name)
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self.rename_column(table_name, name, renamed)
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self.add_column(table_name, name, field, keep_default=False) |
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self.execute("UPDATE %s set %s=%s" % ( |
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self.quote_name(table_name),
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self.quote_name(name),
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self.quote_name(renamed),
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)) |
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self.delete_column(table_name, renamed)
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def _generate_temp_name(self, for_name): |
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suffix = hex(hash(for_name)).upper()[1:] |
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return self.normalize_name(for_name + "_" + suffix) |
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@generic.copy_column_constraints #TODO: Appears to be nulled by the delete decorator below... |
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@generic.delete_column_constraints
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def rename_column(self, table_name, old, new): |
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if old == new:
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# Short-circuit out
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return []
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self.execute('ALTER TABLE %s RENAME COLUMN %s TO %s;' % ( |
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self.quote_name(table_name),
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self.quote_name(old),
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self.quote_name(new),
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)) |
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@generic.invalidate_table_constraints
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def add_column(self, table_name, name, field, keep_default=True): |
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sql = self.column_sql(table_name, name, field)
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sql = self.adj_column_sql(sql)
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if sql:
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params = ( |
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self.quote_name(table_name),
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sql |
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) |
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sql = self.add_column_string % params
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self.execute(sql)
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# Now, drop the default if we need to
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if not keep_default and field.default is not None: |
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field.default = NOT_PROVIDED |
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self.alter_column(table_name, name, field, explicit_name=False) |
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def delete_column(self, table_name, name): |
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return super(DatabaseOperations, self).delete_column(self.quote_name(table_name), name) |
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def lookup_constraint(self, db_name, table_name, column_name=None): |
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if column_name:
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# Column names in the constraint cache come from the database,
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# make sure we use the properly shortened/uppercased version
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# for lookup.
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column_name = self.normalize_name(column_name)
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return super(DatabaseOperations, self).lookup_constraint(db_name, table_name, column_name) |
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def _constraints_affecting_columns(self, table_name, columns, type="UNIQUE"): |
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if columns:
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columns = [self.normalize_name(c) for c in columns] |
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return super(DatabaseOperations, self)._constraints_affecting_columns(table_name, columns, type) |
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def _field_sanity(self, field): |
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"""
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This particular override stops us sending DEFAULTs for BooleanField.
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"""
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if isinstance(field, models.BooleanField) and field.has_default(): |
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field.default = int(field.to_python(field.get_default()))
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return field
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def _default_value_workaround(self, value): |
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from datetime import date,time,datetime |
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if isinstance(value, (date,time,datetime)): |
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return "'%s'" % value |
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else:
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return super(DatabaseOperations, self)._default_value_workaround(value) |
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def _fill_constraint_cache(self, db_name, table_name): |
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self._constraint_cache.setdefault(db_name, {})
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self._constraint_cache[db_name][table_name] = {}
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rows = self.execute(""" |
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SELECT user_cons_columns.constraint_name,
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user_cons_columns.column_name,
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user_constraints.constraint_type
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FROM user_constraints
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JOIN user_cons_columns ON
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user_constraints.table_name = user_cons_columns.table_name AND
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user_constraints.constraint_name = user_cons_columns.constraint_name
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WHERE user_constraints.table_name = '%s'
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""" % self.normalize_name(table_name)) |
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for constraint, column, kind in rows: |
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self._constraint_cache[db_name][table_name].setdefault(column, set()) |
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self._constraint_cache[db_name][table_name][column].add((self.constraints_dict[kind], constraint)) |
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return
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