选择总和（金额）作为条件对总

Question

我想，总交易用户超过50000

SELECT sum(tractions.amount) as total , user_id FROM `tractions` where `total` > 50000 group by user_id 

我得到这个错误总

#1054 - Unknown column 'total' in 'where clause' 

诅咒

没有总列在表中，但我应该怎么写条件？

Answer 1

你需要一个having子句聚集总数：

SELECT sum(tractions.amount) as total , user_id 
FROM `tractions` 
group by user_id 
HAVING total > 50000; 

编辑：

如果我写这个查询时，它看起来像这样：

select t.user_id, sum(t.amount) as total 
from tractions t 
group by t.user_id 
having sum(t.amount) > 50000; 

我发现大写关键字会分散注意力。我（几乎）总是将我正在聚合的字段放在行首。我大量使用表别名，它们是表格的缩写。我不会逃避标识符，因为我从不在标识符中使用保留字或特殊字符。我把这个表达式放在having子句中，因为。 。 。好吧，我曾经想过，并非所有数据库都支持在having子句中使用列别名。

Answer 2

试试这个

SELECT sum(tractions.amount) as total , user_id FROM `tractions` where sum(tractions.amount) > 50000 group by user_id 

Answer 3

SELECT sum(tractions.amount) as total , user_id 
FROM `tractions` 
where sum(tractions.amount) > 50000 
group by user_id 

Answer 4

SELECT 
    sum(tractions.amount) as total, user_id 
FROM 
    `tractions` 
group by user_id 
having total > 50000;