from django.db.backends.base.introspection import ( BaseDatabaseIntrospection, FieldInfo, TableInfo, ) from django.db.models.indexes import Index class DatabaseIntrospection(BaseDatabaseIntrospection): # Maps type codes to Django Field types. data_types_reverse = { 16: 'BooleanField', 17: 'BinaryField', 20: 'BigIntegerField', 21: 'SmallIntegerField', 23: 'IntegerField', 25: 'TextField', 700: 'FloatField', 701: 'FloatField', 869: 'GenericIPAddressField', 1042: 'CharField', # blank-padded 1043: 'CharField', 1082: 'DateField', 1083: 'TimeField', 1114: 'DateTimeField', 1184: 'DateTimeField', 1266: 'TimeField', 1700: 'DecimalField', 2950: 'UUIDField', } ignored_tables = [] def get_field_type(self, data_type, description): field_type = super().get_field_type(data_type, description) if description.default and 'nextval' in description.default: if field_type == 'IntegerField': return 'AutoField' elif field_type == 'BigIntegerField': return 'BigAutoField' return field_type def get_table_list(self, cursor): """Return a list of table and view names in the current database.""" cursor.execute(""" SELECT c.relname, c.relkind 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 [TableInfo(row[0], {'r': 't', 'v': 'v'}.get(row[1])) for row in cursor.fetchall() if row[0] not in self.ignored_tables] def get_table_description(self, cursor, table_name): """ Return a description of the table with the DB-API cursor.description interface. """ # As cursor.description does not return reliably the nullable property, # we have to query the information_schema (#7783) cursor.execute(""" SELECT column_name, is_nullable, column_default FROM information_schema.columns WHERE table_name = %s""", [table_name]) field_map = {line[0]: line[1:] for line in cursor.fetchall()} cursor.execute("SELECT * FROM %s LIMIT 1" % self.connection.ops.quote_name(table_name)) return [ FieldInfo(*line[0:6], field_map[line.name][0] == 'YES', field_map[line.name][1]) for line in cursor.description ] def get_sequences(self, cursor, table_name, table_fields=()): sequences = [] cursor.execute(""" SELECT s.relname as sequence_name, col.attname FROM pg_class s JOIN pg_namespace sn ON sn.oid = s.relnamespace JOIN pg_depend d ON d.refobjid = s.oid AND d.refclassid='pg_class'::regclass JOIN pg_attrdef ad ON ad.oid = d.objid AND d.classid = 'pg_attrdef'::regclass JOIN pg_attribute col ON col.attrelid = ad.adrelid AND col.attnum = ad.adnum JOIN pg_class tbl ON tbl.oid = ad.adrelid JOIN pg_namespace n ON n.oid = tbl.relnamespace WHERE s.relkind = 'S' AND d.deptype in ('a', 'n') AND n.nspname = 'public' AND tbl.relname = %s """, [table_name]) for row in cursor.fetchall(): sequences.append({'name': row[0], 'table': table_name, 'column': row[1]}) return sequences def get_relations(self, cursor, table_name): """ Return a dictionary of {field_name: (field_name_other_table, other_table)} representing all relationships to the given table. """ cursor.execute(""" SELECT c2.relname, a1.attname, a2.attname FROM pg_constraint con LEFT JOIN pg_class c1 ON con.conrelid = c1.oid LEFT JOIN pg_class c2 ON con.confrelid = c2.oid LEFT JOIN pg_attribute a1 ON c1.oid = a1.attrelid AND a1.attnum = con.conkey[1] LEFT JOIN pg_attribute a2 ON c2.oid = a2.attrelid AND a2.attnum = con.confkey[1] WHERE c1.relname = %s AND con.contype = 'f'""", [table_name]) relations = {} for row in cursor.fetchall(): relations[row[1]] = (row[2], row[0]) return relations def get_key_columns(self, cursor, table_name): key_columns = [] cursor.execute(""" SELECT kcu.column_name, ccu.table_name AS referenced_table, ccu.column_name AS referenced_column FROM information_schema.constraint_column_usage ccu LEFT JOIN information_schema.key_column_usage kcu ON ccu.constraint_catalog = kcu.constraint_catalog AND ccu.constraint_schema = kcu.constraint_schema AND ccu.constraint_name = kcu.constraint_name LEFT JOIN information_schema.table_constraints tc ON ccu.constraint_catalog = tc.constraint_catalog AND ccu.constraint_schema = tc.constraint_schema AND ccu.constraint_name = tc.constraint_name WHERE kcu.table_name = %s AND tc.constraint_type = 'FOREIGN KEY'""", [table_name]) key_columns.extend(cursor.fetchall()) return key_columns def get_constraints(self, cursor, table_name): """ Retrieve any constraints or keys (unique, pk, fk, check, index) across one or more columns. Also retrieve the definition of expression-based indexes. """ constraints = {} # Loop over the key table, collecting things as constraints. The column # array must return column names in the same order in which they were # created. cursor.execute(""" SELECT c.conname, array( SELECT attname FROM unnest(c.conkey) WITH ORDINALITY cols(colid, arridx) JOIN pg_attribute AS ca ON cols.colid = ca.attnum WHERE ca.attrelid = c.conrelid ORDER BY cols.arridx ), c.contype, (SELECT fkc.relname || '.' || fka.attname FROM pg_attribute AS fka JOIN pg_class AS fkc ON fka.attrelid = fkc.oid WHERE fka.attrelid = c.confrelid AND fka.attnum = c.confkey[1]), cl.reloptions FROM pg_constraint AS c JOIN pg_class AS cl ON c.conrelid = cl.oid JOIN pg_namespace AS ns ON cl.relnamespace = ns.oid WHERE ns.nspname = %s AND cl.relname = %s """, ["public", table_name]) for constraint, columns, kind, used_cols, options in cursor.fetchall(): constraints[constraint] = { "columns": columns, "primary_key": kind == "p", "unique": kind in ["p", "u"], "foreign_key": tuple(used_cols.split(".", 1)) if kind == "f" else None, "check": kind == "c", "index": False, "definition": None, "options": options, } # Now get indexes cursor.execute(""" SELECT indexname, array_agg(attname ORDER BY arridx), indisunique, indisprimary, array_agg(ordering ORDER BY arridx), amname, exprdef, s2.attoptions FROM ( SELECT c2.relname as indexname, idx.*, attr.attname, am.amname, CASE WHEN idx.indexprs IS NOT NULL THEN pg_get_indexdef(idx.indexrelid) END AS exprdef, CASE am.amname WHEN 'btree' THEN CASE (option & 1) WHEN 1 THEN 'DESC' ELSE 'ASC' END END as ordering, c2.reloptions as attoptions FROM ( SELECT * FROM pg_index i, unnest(i.indkey, i.indoption) WITH ORDINALITY koi(key, option, arridx) ) idx LEFT JOIN pg_class c ON idx.indrelid = c.oid LEFT JOIN pg_class c2 ON idx.indexrelid = c2.oid LEFT JOIN pg_am am ON c2.relam = am.oid LEFT JOIN pg_attribute attr ON attr.attrelid = c.oid AND attr.attnum = idx.key WHERE c.relname = %s ) s2 GROUP BY indexname, indisunique, indisprimary, amname, exprdef, attoptions; """, [table_name]) for index, columns, unique, primary, orders, type_, definition, options in cursor.fetchall(): if index not in constraints: constraints[index] = { "columns": columns if columns != [None] else [], "orders": orders if orders != [None] else [], "primary_key": primary, "unique": unique, "foreign_key": None, "check": False, "index": True, "type": Index.suffix if type_ == 'btree' else type_, "definition": definition, "options": options, } return constraints