摘要:
方法一: select IF(ISNULL(columnName) OR columnName='',0,columnName) from tableName; 方法二: select case when ISNULL(columnName) OR columnName='' then 0 else 阅读全文
摘要:
1.根据名称分组去重,并查询记录ID select max(id) from T_TABLE GROUP BY name 2.根据ID获取记录 select * from T_TABLE where ID in ( select max(id) from T_TABLE GROUP BY name 阅读全文