Fixed #9779: added support for relation detection to inspectdb under SQLite....

import re

from django.db.backends import BaseDatabaseIntrospection

# This light wrapper "fakes" a dictionary interface, because some SQLite data

                 info['null_ok']) for info in self._table_info(cursor, table_name)]

    def get_relations(self, cursor, table_name):

        raise NotImplementedError

        """ 

        Returns a dictionary of {field_index: (field_index_other_table, other_table)} 

        representing all relationships to the given table. Indexes are 0-based. 

        """ 

        # Dictionary of relations to return 

        relations = {} 

        # Schema for this table 

        cursor.execute("SELECT sql FROM sqlite_master WHERE tbl_name = %s", [table_name]) 

        results = cursor.fetchone()[0].strip() 

        results = results.split('(', 1)[1] 

        results = results.rsplit(')', 1)[0] 

        # Walk through and look for references to other tables. SQLite doesn't

        # really have enforced references, but since it echoes out the SQL used

        # to create the table we can look for REFERENCES statements used there.

        for field_index, field_desc in enumerate(results.split(',')): 

            field_desc = field_desc.strip() 

            if field_desc.startswith("UNIQUE"): 

                continue 

            m = re.search('references (.*) \(["|](.*)["|]\)', field_desc, re.I)

            if not m: 

                continue 

            table, column = [s.strip('"') for s in m.groups()]

            cursor.execute("SELECT sql FROM sqlite_master WHERE tbl_name = %s", [table])

            result = cursor.fetchone()

            if not result:

                continue

            other_table_results = result[0].strip() 

            other_table_results = other_table_results.split('(', 1)[1] 

            other_table_results = other_table_results.rsplit(')', 1)[0] 

            for other_index, other_desc in enumerate(other_table_results.split(',')): 

                other_desc = other_desc.strip() 

                if other_desc.startswith('UNIQUE'): 

                    continue 

                name = other_desc.split(' ', 1)[0].strip('"') 

                if name == column: 

                    relations[field_index] = (other_index, table)

                    break

        return relations

    def get_indexes(self, cursor, table_name):

        """