Question

我试图运行以下查询，我收到以下错误：

您的SQL语法有错误;检查手册对应于您的MySQL服务器版本，以便使用正确的语法靠近'sum（sl.duration）作为持续时间，sum（sl.quantity_loss）为 quantity_loss'

SELECT 
   lr.uid AS loss_reason_uid,
   gl.uid AS gl_uid,
   lt.uid AS lt_uid,
   SUM(sl.duration * b.marginal_value_downtime) AS value_loss where en.state = 'downtime',
   SUM(sl.quantity_loss * p.marginal_value) as value_loss where en.state != 'downtime',
   SUM(sl.duration) AS duration,
   SUM(sl.quantity_loss) AS quantity_loss,
   COUNT(*) AS count
FROM
    sub_losses AS sl

知道为什么会出现这种语法错误吗？

Answer 1

尝试使用：除了以上评论之外，不允许在一个查询块中多次使用相同的ALIAS或COLUMN NAME，因此我已经{{1制作是独一无二的。

value_loss1

Answer 2

这对我有用。感谢@HoneyBadger的指导。

SELECT 
    lr.uid AS loss_reason_uid,
        gl.uid AS gl_uid,
        lt.uid AS lt_uid,
        SUM(CASE WHEN en.state = 'downtime' THEN sl.duration * b.marginal_value_downtime ELSE sl.quantity_loss * p.marginal_value END) AS value_loss,
        SUM(sl.duration) AS duration,
        SUM(sl.quantity_loss) AS quantity_loss,
        COUNT(*) AS count
FROM
    sub_losses AS sl

SQL查询中的语法错误：意外的“SUM”（总和）

2 个答案: