| from django.db.backends import BaseDatabaseIntrospection |
| |
| class DatabaseIntrospection(BaseDatabaseIntrospection): |
| # Maps type codes to Django Field types. |
| data_types_reverse = { |
| 16: 'BooleanField', |
| 20: 'BigIntegerField', |
| 21: 'SmallIntegerField', |
| 23: 'IntegerField', |
| 25: 'TextField', |
| 700: 'FloatField', |
| 701: 'FloatField', |
| 869: 'IPAddressField', |
| 1043: 'CharField', |
| 1082: 'DateField', |
| 1083: 'TimeField', |
| 1114: 'DateTimeField', |
| 1184: 'DateTimeField', |
| 1266: 'TimeField', |
| 1700: 'DecimalField', |
| } |
| |
| def get_table_list(self, cursor): |
| "Returns a list of table names in the current database." |
| cursor.execute(""" |
| SELECT c.relname |
| FROM pg_catalog.pg_class c |
| LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace |
| WHERE c.relkind IN ('r', 'v', '') |
| AND n.nspname NOT IN ('pg_catalog', 'pg_toast') |
| AND pg_catalog.pg_table_is_visible(c.oid)""") |
| return [row[0] for row in cursor.fetchall()] |
| |
| def get_table_description(self, cursor, table_name): |
| "Returns a description of the table, with the DB-API cursor.description interface." |
| cursor.execute("SELECT * FROM %s LIMIT 1" % self.connection.ops.quote_name(table_name)) |
| return cursor.description |
| |
| def get_relations(self, cursor, table_name): |
| """ |
| Returns a dictionary of {field_index: (field_index_other_table, other_table)} |
| representing all relationships to the given table. Indexes are 0-based. |
| """ |
| cursor.execute(""" |
| SELECT con.conkey, con.confkey, c2.relname |
| FROM pg_constraint con, pg_class c1, pg_class c2 |
| WHERE c1.oid = con.conrelid |
| AND c2.oid = con.confrelid |
| AND c1.relname = %s |
| AND con.contype = 'f'""", [table_name]) |
| relations = {} |
| for row in cursor.fetchall(): |
| try: |
| # row[0] and row[1] are like "{2}", so strip the curly braces. |
| relations[int(row[0][1:-1]) - 1] = (int(row[1][1:-1]) - 1, row[2]) |
| except ValueError: |
| continue |
| return relations |
| |
| def get_indexes(self, cursor, table_name): |
| """ |
| Returns a dictionary of fieldname -> infodict for the given table, |
| where each infodict is in the format: |
| {'primary_key': boolean representing whether it's the primary key, |
| 'unique': boolean representing whether it's a unique index} |
| """ |
| # This query retrieves each index on the given table, including the |
| # first associated field name |
| cursor.execute(""" |
| SELECT attr.attname, idx.indkey, idx.indisunique, idx.indisprimary |
| FROM pg_catalog.pg_class c, pg_catalog.pg_class c2, |
| pg_catalog.pg_index idx, pg_catalog.pg_attribute attr |
| WHERE c.oid = idx.indrelid |
| AND idx.indexrelid = c2.oid |
| AND attr.attrelid = c.oid |
| AND attr.attnum = idx.indkey[0] |
| AND c.relname = %s""", [table_name]) |
| indexes = {} |
| for row in cursor.fetchall(): |
| # row[1] (idx.indkey) is stored in the DB as an array. It comes out as |
| # a string of space-separated integers. This designates the field |
| # indexes (1-based) of the fields that have indexes on the table. |
| # Here, we skip any indexes across multiple fields. |
| if ' ' in row[1]: |
| continue |
| indexes[row[0]] = {'primary_key': row[3], 'unique': row[2]} |
| return indexes |
| |