sql实现多字段求和并查询

下面就sql多字段求和并作为sql查询条件的方法进行了说明供您参考希望对您学习sql查询方面有所帮助

做一个字段求和的小sql查询查询一个表中字段字段和字段之和大于的结果故写了如下的SQL语句

有一点要注意的是在Where字句中不能有自己运算后得到的字段

sqlstr = "SELECT WIDWWeathergreenColor(SELECT redColor+greenColor+blueColor FROM Weather N WHERE NID = WID) AS AllValue FROM Weather W WHERE (SELECT redColor+greenColor+blueColor FROM Weather N WHERE NID = WID)> ORDER BY ID";

即如下的SQL语句是行不通的说是"至少一个参数没有被指定值"

sqlstr = "SELECT WIDWWeathergreenColor(SELECT redColor+greenColor+blueColor FROM Weather N WHERE NID = WID) AS AllValue FROM Weather W WHERE AllValue > ORDER BY ID";