摘要:
我有以下select语句,如果没有匹配的行,我希望它返回一个默认值.这是我使用的行: SELECT id FROM `ylt_sys_area` WHERE NAME ='琼海市'; 结果如下: 修改sql语句: SELECT IFNULL(MIN(id), NULL) FROM `ylt_sys_ 阅读全文
摘要:
报错如下: Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column ‘a.id’ which is not functionally dependent on columns i 阅读全文