1 | | from django.db.backends.postgresql.introspection import * |
| 1 | from django.db import transaction |
| 2 | from django.db.backends.postgresql_psycopg2.base import quote_name |
| 3 | |
| 4 | def get_table_list(cursor): |
| 5 | "Returns a list of table names in the current database." |
| 6 | cursor.execute(""" |
| 7 | SELECT c.relname |
| 8 | FROM pg_catalog.pg_class c |
| 9 | LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace |
| 10 | WHERE c.relkind IN ('r', 'v', '') |
| 11 | AND n.nspname NOT IN ('pg_catalog', 'pg_toast') |
| 12 | AND pg_catalog.pg_table_is_visible(c.oid)""") |
| 13 | return [row[0] for row in cursor.fetchall()] |
| 14 | |
| 15 | def get_table_description(cursor, table_name): |
| 16 | "Returns a description of the table, with the DB-API cursor.description interface." |
| 17 | cursor.execute("SELECT * FROM %s LIMIT 1" % quote_name(table_name)) |
| 18 | return cursor.description |
| 19 | |
| 20 | def get_relations(cursor, table_name): |
| 21 | """ |
| 22 | Returns a dictionary of {field_index: (field_index_other_table, other_table)} |
| 23 | representing all relationships to the given table. Indexes are 0-based. |
| 24 | """ |
| 25 | cursor.execute(""" |
| 26 | SELECT con.conkey, con.confkey, c2.relname |
| 27 | FROM pg_constraint con, pg_class c1, pg_class c2 |
| 28 | WHERE c1.oid = con.conrelid |
| 29 | AND c2.oid = con.confrelid |
| 30 | AND c1.relname = %s |
| 31 | AND con.contype = 'f'""", [table_name]) |
| 32 | relations = {} |
| 33 | for row in cursor.fetchall(): |
| 34 | try: |
| 35 | # row[0] and row[1] are like "{2}", so strip the curly braces. |
| 36 | relations[int(row[0][1:-1]) - 1] = (int(row[1][1:-1]) - 1, row[2]) |
| 37 | except ValueError: |
| 38 | continue |
| 39 | return relations |
| 40 | |
| 41 | def get_indexes(cursor, table_name): |
| 42 | """ |
| 43 | Returns a dictionary of fieldname -> infodict for the given table, |
| 44 | where each infodict is in the format: |
| 45 | {'primary_key': boolean representing whether it's the primary key, |
| 46 | 'unique': boolean representing whether it's a unique index} |
| 47 | """ |
| 48 | # Get the table description because we only have the column indexes, and we |
| 49 | # need the column names. |
| 50 | desc = get_table_description(cursor, table_name) |
| 51 | # This query retrieves each index on the given table. |
| 52 | cursor.execute(""" |
| 53 | SELECT idx.indkey, idx.indisunique, idx.indisprimary |
| 54 | FROM pg_catalog.pg_class c, pg_catalog.pg_class c2, |
| 55 | pg_catalog.pg_index idx |
| 56 | WHERE c.oid = idx.indrelid |
| 57 | AND idx.indexrelid = c2.oid |
| 58 | AND c.relname = %s""", [table_name]) |
| 59 | indexes = {} |
| 60 | for row in cursor.fetchall(): |
| 61 | # row[0] (idx.indkey) is stored in the DB as an array. It comes out as |
| 62 | # a string of space-separated integers. This designates the field |
| 63 | # indexes (1-based) of the fields that have indexes on the table. |
| 64 | # Here, we skip any indexes across multiple fields. |
| 65 | if ' ' in row[0]: |
| 66 | continue |
| 67 | col_name = desc[int(row[0])-1][0] |
| 68 | indexes[col_name] = {'primary_key': row[2], 'unique': row[1]} |
| 69 | return indexes |
| 70 | |
| 71 | # Maps type codes to Django Field types. |
| 72 | DATA_TYPES_REVERSE = { |
| 73 | 16: 'BooleanField', |
| 74 | 21: 'SmallIntegerField', |
| 75 | 23: 'IntegerField', |
| 76 | 25: 'TextField', |
| 77 | 869: 'IPAddressField', |
| 78 | 1043: 'CharField', |
| 79 | 1082: 'DateField', |
| 80 | 1083: 'TimeField', |
| 81 | 1114: 'DateTimeField', |
| 82 | 1184: 'DateTimeField', |
| 83 | 1266: 'TimeField', |
| 84 | 1700: 'FloatField', |
| 85 | } |