compare.py 文件源码

def _compare_type(schema, tname, cname, conn_col,
                  metadata_col, diffs,
                  autogen_context):

    conn_type = conn_col.type
    metadata_type = metadata_col.type
    if conn_type._type_affinity is sqltypes.NullType:
        log.info("Couldn't determine database type "
                 "for column '%s.%s'", tname, cname)
        return
    if metadata_type._type_affinity is sqltypes.NullType:
        log.info("Column '%s.%s' has no type within "
                 "the model; can't compare", tname, cname)
        return

    isdiff = autogen_context['context']._compare_type(conn_col, metadata_col)

    if isdiff:

        diffs.append(
            ("modify_type", schema, tname, cname,
             {
                 "existing_nullable": conn_col.nullable,
                 "existing_server_default": conn_col.server_default,
             },
             conn_type,
             metadata_type),
        )
        log.info("Detected type change from %r to %r on '%s.%s'",
                 conn_type, metadata_type, tname, cname
                 )