查询配件主数据表(tbl_part_base_info)的所有数据和配件是否有物料(物料表(tbl_material)中有配件主数据表的part_no,就表示有物料,反之,则表示没有物料),用sql中的case when...then...else...end来实现
第一种写法:
select info.*,(case when material.part_no is null then ‘否‘ else ‘是‘ end) hasMaterial
from tbl_part_base_info info left join tbl_material material on info.part_no=material.part_no;
第二种写法:
select info.*,(case material.part_no when is null then ‘否‘ else ‘是‘ end) from tbl_part_base_info info left join tbl_material material on info.part_no=material.part_no;
时间: 2024-10-11 07:09:20