MySQL根据业务场景归纳常用SQL语句

素材表：user[{"id":1,"name":"x"},{"id":2,"name":"x"},{"id":3,"name":"y"},{"id":4,"name":"y"},{"id":5,"name":"z"},{"id":6,"name":"x"}]素材表：user[{"id":1,"name":"x"},{"id":2,"name":"x"}