sql.py 文件源码

def custom_sql_for_model(model, style, connection):
    opts = model._meta
    app_dir = os.path.normpath(os.path.join(os.path.dirname(upath(models.get_app(model._meta.app_label).__file__)), 'sql'))
    output = []

    # Post-creation SQL should come before any initial SQL data is loaded.
    # However, this should not be done for models that are unmanaged or
    # for fields that are part of a parent model (via model inheritance).
    if opts.managed:
        post_sql_fields = [f for f in opts.local_fields if hasattr(f, 'post_create_sql')]
        for f in post_sql_fields:
            output.extend(f.post_create_sql(style, model._meta.db_table))

    # Find custom SQL, if it's available.
    backend_name = connection.settings_dict['ENGINE'].split('.')[-1]
    sql_files = [os.path.join(app_dir, "%s.%s.sql" % (opts.model_name, backend_name)),
                 os.path.join(app_dir, "%s.sql" % opts.model_name)]
    for sql_file in sql_files:
        if os.path.exists(sql_file):
            with codecs.open(sql_file, 'U', encoding=settings.FILE_CHARSET) as fp:
                # Some backends can't execute more than one SQL statement at a time,
                # so split into separate statements.
                output.extend(_split_statements(fp.read()))
    return output