def get_relations(cursor, table_name):
    my_field_dict = _name_to_index(cursor, table_name)
    constraints = []
    relations = {}
    try:
        # This should work for MySQL 5.0.
        cursor.execute("""
            SELECT column_name, referenced_table_name, referenced_column_name
            FROM information_schema.key_column_usage
            WHERE table_name = %s
                AND table_schema = DATABASE()
                AND referenced_table_name IS NOT NULL
                AND referenced_column_name IS NOT NULL""", [table_name])
        constraints.extend(cursor.fetchall())
    except (ProgrammingError, OperationalError):
        # Fall back to "SHOW CREATE TABLE", for previous MySQL versions.
        # Go through all constraints and save the equal matches.
        cursor.execute("SHOW CREATE TABLE %s" % quote_name(table_name))
        for row in cursor.fetchall():
            pos = 0
            while True:
                match = foreign_key_re.search(row[1], pos)
                if match == None:
                    break
                pos = match.end()
                constraints.append(match.groups())

    for my_fieldname, other_table, other_field in constraints:
        other_field_index = _name_to_index(cursor, other_table)[other_field]
        my_field_index = my_field_dict[my_fieldname]
        relations[my_field_index] = (other_field_index, other_table)

    return relations
Returns a dictionary of {field_index: (field_index_other_table, other_table)}
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-0.96/django/db/backends/mysql_old/introspection.py/get_relations