app/django/db/backends/sqlite3/introspection.py
author Sverre Rabbelier <srabbelier@gmail.com>
Fri, 23 Jan 2009 21:20:33 +0000 (2009-01-23)
changeset 935 09f47e08f805
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Adust the as_table tag to render a pick link if appropriate The templates are adjusted to pass on a 'reference' value, which is the url_name of the view from which the entity should be picked. The as_table (and related) function(s) construct and then pass on this argument and enable takes_contex so that we have access to the context of the enclosing template. We only extract ReferenceProperties that end with '_link_id' since that is how all RP's are currently named. It is not possible to create a field with the same name as the RP, as GAE will try to interpret it's contents as the key of an entity before even calling any function we can override. Patch by: Sverre Rabbelier
from django.db.backends import BaseDatabaseIntrospection

# 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:
    # 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',
        'smallint unsigned': 'PositiveSmallIntegerField',
        'smallinteger': 'SmallIntegerField',
        'int': 'IntegerField',
        'integer': 'IntegerField',
        'integer unsigned': 'PositiveIntegerField',
        'decimal': 'DecimalField',
        'real': 'FloatField',
        'text': 'TextField',
        'char': 'CharField',
        'date': 'DateField',
        'datetime': 'DateTimeField',
        'time': 'TimeField',
    }

    def __getitem__(self, key):
        key = key.lower()
        try:
            return self.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', {'max_length': int(m.group(1))})
            raise KeyError

class DatabaseIntrospection(BaseDatabaseIntrospection):
    data_types_reverse = FlexibleFieldLookupDict()

    def get_table_list(self, 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(self, 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 self._table_info(cursor, table_name)]

    def get_relations(self, cursor, table_name):
        raise NotImplementedError

    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}
        """
        indexes = {}
        for info in self._table_info(cursor, table_name):
            indexes[info['name']] = {'primary_key': info['pk'] != 0,
                                     'unique': False}
        cursor.execute('PRAGMA index_list(%s)' % self.connection.ops.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)' % self.connection.ops.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(self, cursor, name):
        cursor.execute('PRAGMA table_info(%s)' % self.connection.ops.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()]