django1/django/db/backends/sqlite3/introspection.py

88 lines
3.2 KiB
Python

from django.db.backends.sqlite3.base import quote_name
def get_table_list(cursor):
"Returns a list of table names in the current database."
# Skip the sqlite_sequence system table used for autoincrement key
# generation.
cursor.execute("""
SELECT name FROM sqlite_master
WHERE type='table' AND NOT name='sqlite_sequence'
ORDER BY name""")
return [row[0] for row in cursor.fetchall()]
def get_table_description(cursor, table_name):
"Returns a description of the table, with the DB-API cursor.description interface."
return [(info['name'], info['type'], None, None, None, None,
info['null_ok']) for info in _table_info(cursor, table_name)]
def get_relations(cursor, table_name):
raise NotImplementedError
def get_indexes(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}
"""
indexes = {}
for info in _table_info(cursor, table_name):
indexes[info['name']] = {'primary_key': info['pk'] != 0,
'unique': False}
cursor.execute('PRAGMA index_list(%s)' % quote_name(table_name))
# seq, name, unique
for index, unique in [(field[1], field[2]) for field in cursor.fetchall()]:
if not unique:
continue
cursor.execute('PRAGMA index_info(%s)' % quote_name(index))
info = cursor.fetchall()
# Skip indexes across multiple fields
if len(info) != 1:
continue
name = info[0][2] # seqno, cid, name
indexes[name]['unique'] = True
return indexes
def _table_info(cursor, name):
cursor.execute('PRAGMA table_info(%s)' % quote_name(name))
# cid, name, type, notnull, dflt_value, pk
return [{'name': field[1],
'type': field[2],
'null_ok': not field[3],
'pk': field[5] # undocumented
} for field in cursor.fetchall()]
# Maps SQL types to Django Field types. Some of the SQL types have multiple
# entries here because SQLite allows for anything and doesn't normalize the
# field type; it uses whatever was given.
BASE_DATA_TYPES_REVERSE = {
'bool': 'BooleanField',
'boolean': 'BooleanField',
'smallint': 'SmallIntegerField',
'smallinteger': 'SmallIntegerField',
'int': 'IntegerField',
'integer': 'IntegerField',
'text': 'TextField',
'char': 'CharField',
'date': 'DateField',
'datetime': 'DateTimeField',
'time': 'TimeField',
}
# This light wrapper "fakes" a dictionary interface, because some SQLite data
# types include variables in them -- e.g. "varchar(30)" -- and can't be matched
# as a simple dictionary lookup.
class FlexibleFieldLookupDict:
def __getitem__(self, key):
key = key.lower()
try:
return BASE_DATA_TYPES_REVERSE[key]
except KeyError:
import re
m = re.search(r'^\s*(?:var)?char\s*\(\s*(\d+)\s*\)\s*$', key)
if m:
return ('CharField', {'maxlength': int(m.group(1))})
raise KeyError
DATA_TYPES_REVERSE = FlexibleFieldLookupDict()