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', 1186: 'DurationField', 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' elif field_type == 'SmallIntegerField': return 'SmallAutoField' 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, CASE WHEN {} THEN 'p' WHEN c.relkind IN ('m', 'v') THEN 'v' ELSE 't' END FROM pg_catalog.pg_class c LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace WHERE c.relkind IN ('f', 'm', 'p', 'r', 'v') AND n.nspname NOT IN ('pg_catalog', 'pg_toast') AND pg_catalog.pg_table_is_visible(c.oid) """.format('c.relispartition' if self.connection.features.supports_table_partitions else 'FALSE')) return [TableInfo(*row) 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. """ # Query the pg_catalog tables as cursor.description does not reliably # return the nullable property and information_schema.columns does not # contain details of materialized views. cursor.execute(""" SELECT a.attname AS column_name, NOT (a.attnotnull OR (t.typtype = 'd' AND t.typnotnull)) AS is_nullable, pg_get_expr(ad.adbin, ad.adrelid) AS column_default FROM pg_attribute a LEFT JOIN pg_attrdef ad ON a.attrelid = ad.adrelid AND a.attnum = ad.adnum JOIN pg_type t ON a.atttypid = t.oid JOIN pg_class c ON a.attrelid = c.oid JOIN pg_namespace n ON c.relnamespace = n.oid WHERE c.relkind IN ('f', 'm', 'p', 'r', 'v') AND c.relname = %s AND n.nspname NOT IN ('pg_catalog', 'pg_toast') AND pg_catalog.pg_table_is_visible(c.oid) """, [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.name, line.type_code, line.display_size, line.internal_size, line.precision, line.scale, *field_map[line.name], ) for line in cursor.description ] def get_sequences(self, cursor, table_name, table_fields=()): 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 WHERE s.relkind = 'S' AND d.deptype in ('a', 'n') AND pg_catalog.pg_table_is_visible(tbl.oid) AND tbl.relname = %s """, [table_name]) return [ {'name': row[0], 'table': table_name, 'column': row[1]} for row in cursor.fetchall() ] 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. """ return {row[0]: (row[2], row[1]) for row in self.get_key_columns(cursor, table_name)} def get_key_columns(self, cursor, table_name): cursor.execute(""" SELECT a1.attname, c2.relname, 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' AND c1.relnamespace = c2.relnamespace AND pg_catalog.pg_table_is_visible(c1.oid) """, [table_name]) return cursor.fetchall() 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 WHERE cl.relname = %s AND pg_catalog.pg_table_is_visible(cl.oid) """, [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 AND pg_catalog.pg_table_is_visible(c.oid) ) 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: basic_index = type_ == 'btree' and not index.endswith('_btree') and options is None 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 basic_index else type_, "definition": definition, "options": options, } return constraints