--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/db/backends/postgresql/operations.py Wed Jan 20 00:34:04 2010 +0100
@@ -0,0 +1,164 @@
+import re
+
+from django.db.backends import BaseDatabaseOperations
+
+# This DatabaseOperations class lives in here instead of base.py because it's
+# used by both the 'postgresql' and 'postgresql_psycopg2' backends.
+
+class DatabaseOperations(BaseDatabaseOperations):
+ def __init__(self):
+ self._postgres_version = None
+
+ def _get_postgres_version(self):
+ if self._postgres_version is None:
+ from django.db import connection
+ from django.db.backends.postgresql.version import get_version
+ cursor = connection.cursor()
+ self._postgres_version = get_version(cursor)
+ return self._postgres_version
+ postgres_version = property(_get_postgres_version)
+
+ def date_extract_sql(self, lookup_type, field_name):
+ # http://www.postgresql.org/docs/8.0/static/functions-datetime.html#FUNCTIONS-DATETIME-EXTRACT
+ if lookup_type == 'week_day':
+ # For consistency across backends, we return Sunday=1, Saturday=7.
+ return "EXTRACT('dow' FROM %s) + 1" % field_name
+ else:
+ return "EXTRACT('%s' FROM %s)" % (lookup_type, field_name)
+
+ def date_trunc_sql(self, lookup_type, field_name):
+ # http://www.postgresql.org/docs/8.0/static/functions-datetime.html#FUNCTIONS-DATETIME-TRUNC
+ return "DATE_TRUNC('%s', %s)" % (lookup_type, field_name)
+
+ def deferrable_sql(self):
+ return " DEFERRABLE INITIALLY DEFERRED"
+
+ def lookup_cast(self, lookup_type):
+ lookup = '%s'
+
+ # Cast text lookups to text to allow things like filter(x__contains=4)
+ if lookup_type in ('iexact', 'contains', 'icontains', 'startswith',
+ 'istartswith', 'endswith', 'iendswith'):
+ lookup = "%s::text"
+
+ # Use UPPER(x) for case-insensitive lookups; it's faster.
+ if lookup_type in ('iexact', 'icontains', 'istartswith', 'iendswith'):
+ lookup = 'UPPER(%s)' % lookup
+
+ return lookup
+
+ def field_cast_sql(self, db_type):
+ if db_type == 'inet':
+ return 'HOST(%s)'
+ return '%s'
+
+ def last_insert_id(self, cursor, table_name, pk_name):
+ cursor.execute("SELECT CURRVAL('\"%s_%s_seq\"')" % (table_name, pk_name))
+ return cursor.fetchone()[0]
+
+ def no_limit_value(self):
+ return None
+
+ def quote_name(self, name):
+ if name.startswith('"') and name.endswith('"'):
+ return name # Quoting once is enough.
+ return '"%s"' % name
+
+ def sql_flush(self, style, tables, sequences):
+ if tables:
+ if self.postgres_version[0:2] >= (8,1):
+ # Postgres 8.1+ can do 'TRUNCATE x, y, z...;'. In fact, it *has to*
+ # in order to be able to truncate tables referenced by a foreign
+ # key in any other table. The result is a single SQL TRUNCATE
+ # statement.
+ sql = ['%s %s;' % \
+ (style.SQL_KEYWORD('TRUNCATE'),
+ style.SQL_FIELD(', '.join([self.quote_name(table) for table in tables]))
+ )]
+ else:
+ # Older versions of Postgres can't do TRUNCATE in a single call, so
+ # they must use a simple delete.
+ sql = ['%s %s %s;' % \
+ (style.SQL_KEYWORD('DELETE'),
+ style.SQL_KEYWORD('FROM'),
+ style.SQL_FIELD(self.quote_name(table))
+ ) for table in tables]
+
+ # 'ALTER SEQUENCE sequence_name RESTART WITH 1;'... style SQL statements
+ # to reset sequence indices
+ for sequence_info in sequences:
+ table_name = sequence_info['table']
+ column_name = sequence_info['column']
+ if column_name and len(column_name) > 0:
+ sequence_name = '%s_%s_seq' % (table_name, column_name)
+ else:
+ sequence_name = '%s_id_seq' % table_name
+ sql.append("%s setval('%s', 1, false);" % \
+ (style.SQL_KEYWORD('SELECT'),
+ style.SQL_FIELD(self.quote_name(sequence_name)))
+ )
+ return sql
+ else:
+ return []
+
+ def sequence_reset_sql(self, style, model_list):
+ from django.db import models
+ output = []
+ qn = self.quote_name
+ for model in model_list:
+ # Use `coalesce` to set the sequence for each model to the max pk value if there are records,
+ # or 1 if there are none. Set the `is_called` property (the third argument to `setval`) to true
+ # if there are records (as the max pk value is already in use), otherwise set it to false.
+ for f in model._meta.local_fields:
+ if isinstance(f, models.AutoField):
+ output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
+ (style.SQL_KEYWORD('SELECT'),
+ style.SQL_FIELD(qn('%s_%s_seq' % (model._meta.db_table, f.column))),
+ style.SQL_FIELD(qn(f.column)),
+ style.SQL_FIELD(qn(f.column)),
+ style.SQL_KEYWORD('IS NOT'),
+ style.SQL_KEYWORD('FROM'),
+ style.SQL_TABLE(qn(model._meta.db_table))))
+ break # Only one AutoField is allowed per model, so don't bother continuing.
+ for f in model._meta.many_to_many:
+ if not f.rel.through:
+ output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
+ (style.SQL_KEYWORD('SELECT'),
+ style.SQL_FIELD(qn('%s_id_seq' % f.m2m_db_table())),
+ style.SQL_FIELD(qn('id')),
+ style.SQL_FIELD(qn('id')),
+ style.SQL_KEYWORD('IS NOT'),
+ style.SQL_KEYWORD('FROM'),
+ style.SQL_TABLE(qn(f.m2m_db_table()))))
+ return output
+
+ def savepoint_create_sql(self, sid):
+ return "SAVEPOINT %s" % sid
+
+ def savepoint_commit_sql(self, sid):
+ return "RELEASE SAVEPOINT %s" % sid
+
+ def savepoint_rollback_sql(self, sid):
+ return "ROLLBACK TO SAVEPOINT %s" % sid
+
+ def prep_for_iexact_query(self, x):
+ return x
+
+ def check_aggregate_support(self, aggregate):
+ """Check that the backend fully supports the provided aggregate.
+
+ The population and sample statistics (STDDEV_POP, STDDEV_SAMP,
+ VAR_POP, VAR_SAMP) were first implemented in Postgres 8.2.
+
+ The implementation of population statistics (STDDEV_POP and VAR_POP)
+ under Postgres 8.2 - 8.2.4 is known to be faulty. Raise
+ NotImplementedError if this is the database in use.
+ """
+ if aggregate.sql_function in ('STDDEV_POP', 'STDDEV_SAMP', 'VAR_POP', 'VAR_SAMP'):
+ if self.postgres_version[0:2] < (8,2):
+ raise NotImplementedError('PostgreSQL does not support %s prior to version 8.2. Please upgrade your version of PostgreSQL.' % aggregate.sql_function)
+
+ if aggregate.sql_function in ('STDDEV_POP', 'VAR_POP'):
+ if self.postgres_version[0:2] == (8,2):
+ if self.postgres_version[2] is None or self.postgres_version[2] <= 4:
+ raise NotImplementedError('PostgreSQL 8.2 to 8.2.4 is known to have a faulty implementation of %s. Please upgrade your version of PostgreSQL.' % aggregate.sql_function)