mysql IF条件中的多个表达式

Question

我需要比较表中的一些值，即如果更少，更大和相等......

我的查询如下：

  SELECT `t1`.`K1`
  IF (Sum(`t1`.`K1`) > Sum(`t2`.`K1`), 'Greater', 'Less') AS State
  FROM `t1`
  INNER JOIN `t2` ON `t1`.`Code` = `t2`.`Code`
  GROUP BY `t1`.`K1`

如果值相等，如何实现条件？

Answer 1

SELECT `t1`.`K1`,
       case when Sum(`t1`.`K1`) = Sum(`t2`.`K1`) then 'Equal'
            when Sum(`t1`.`K1`) > Sum(`t2`.`K1`) then 'Greater'
            else 'Less'
       end AS State
FROM `t1`
INNER JOIN `t2` ON `t1`.`Code` = `t2`.`Code`
GROUP BY `t1`.`K1`

Answer 2

SELECT `t1`.`K1`,
IF (Sum(`t1`.`K1`) = Sum(`t2`.`K1`), 'Equal', IF (Sum(`t1`.`K1`) > Sum(`t2`.`K1`), 'Greater', 'Less')) AS State
FROM `t1`
INNER JOIN `t2` ON `t1`.`Code` = `t2`.`Code`
GROUP BY `t1`.`K1`