SQL错误（1054）未知列

我这里有一个很长的sql查询

SELECT c.clientid, c.clientname, c.billingdate, 
case when (select ifnull(sum(total), 0) from invoice i
where i.client = c.clientid and i.isdeleted = 0) - (select ifnull(sum(p.amount), 0) from payment p inner join invoice i on p.invoice = i.invoiceid
where i.client = c.clientid and i.isdeleted = 0) < 0 and i.date < '2012-01-01' then (select ii.total from invoice ii where ii.client = c.clientid order by ii.invoiceid desc limit 1)  else (select ifnull(sum(total), 0) from invoice i
where i.client = c.clientid and i.isdeleted = 0) - (select ifnull(sum(p.amount), 0) from payment p inner join invoice i on p.invoice = i.invoiceid
where i.client = c.clientid and i.isdeleted = 0) end as remaining,
case c.isactive+0
        when '1' then 'Stop'
        else 'Start' 
        end as Active
FROM client c 
ORDER BY clientname

我在该查询中得到一个错误，行I.date<'2012-01-01'表示I.date是字段列表中的未知列…我如何解决此问题

谢谢， J

您在子查询中定义的范围外使用别名i

(select ifnull(sum(total), 0) from invoice i
where i.client = c.clientid and i.isdeleted = 0)

和

您应该包括以下内容：

and i.date < '2012-01-01'

在两个选择中

SELECT c.clientid, c.clientname, c.billingdate, 
case when (select ifnull(sum(total), 0) from invoice i
where i.client = c.clientid and i.isdeleted = 0 and i.date < '2012-01-01' ) - (select ifnull(sum(p.amount), 0) from payment p inner join invoice i on p.invoice = i.invoiceid
where i.client = c.clientid and i.isdeleted = 0 and i.date < '2012-01-01' ) < 0 then (select ii.total from invoice ii where ii.client = c.clientid order by ii.invoiceid desc limit 1)  else (select ifnull(sum(total), 0) from invoice i
where i.client = c.clientid and i.isdeleted = 0) - (select ifnull(sum(p.amount), 0) from payment p inner join invoice i on p.invoice = i.invoiceid
where i.client = c.clientid and i.isdeleted = 0) end as remaining,
case c.isactive+0
        when '1' then 'Stop'
        else 'Start' 
        end as Active
FROM client c 
ORDER BY clientname

您在子查询中定义的范围外使用别名i

(select ifnull(sum(total), 0) from invoice i
where i.client = c.clientid and i.isdeleted = 0)

和

您应该包括以下内容：

and i.date < '2012-01-01'

在两个选择中

SELECT c.clientid, c.clientname, c.billingdate, 
case when (select ifnull(sum(total), 0) from invoice i
where i.client = c.clientid and i.isdeleted = 0 and i.date < '2012-01-01' ) - (select ifnull(sum(p.amount), 0) from payment p inner join invoice i on p.invoice = i.invoiceid
where i.client = c.clientid and i.isdeleted = 0 and i.date < '2012-01-01' ) < 0 then (select ii.total from invoice ii where ii.client = c.clientid order by ii.invoiceid desc limit 1)  else (select ifnull(sum(total), 0) from invoice i
where i.client = c.clientid and i.isdeleted = 0) - (select ifnull(sum(p.amount), 0) from payment p inner join invoice i on p.invoice = i.invoiceid
where i.client = c.clientid and i.isdeleted = 0) end as remaining,
case c.isactive+0
        when '1' then 'Stop'
        else 'Start' 
        end as Active
FROM client c 
ORDER BY clientname

---

您是i.date在子查询之外。就在这里

SELECT c.clientid, c.clientname, c.billingdate, 
CASE WHEN 
    (select ifnull(sum(total), 0) from invoice i where i.client = c.clientid and i.isdeleted = 0)
    - 
    (select ifnull(sum(p.amount), 0) from payment p inner join invoice i on p.invoice = i.invoiceid where i.client = c.clientid and i.isdeleted = 0)
    < 0 
    and i.date < '2012-01-01'  -- THIS IS NOT PART OF THE SUBQUERY
THEN 
    (select ii.total from invoice ii where ii.client = c.clientid order by ii.invoiceid desc limit 1)  
ELSE 
    (select ifnull(sum(total), 0) from invoice i where i.client = c.clientid and i.isdeleted = 0) - (select ifnull(sum(p.amount), 0) from payment p inner join invoice i on p.invoice = i.invoiceid where i.client = c.clientid and i.isdeleted = 0) 
END as remaining,
case c.isactive+0
        when '1' then 'Stop'
        else 'Start' 
        end as Active
FROM client c 
ORDER BY clientname

---

您是i.date在子查询之外。就在这里

SELECT c.clientid, c.clientname, c.billingdate, 
CASE WHEN 
    (select ifnull(sum(total), 0) from invoice i where i.client = c.clientid and i.isdeleted = 0)
    - 
    (select ifnull(sum(p.amount), 0) from payment p inner join invoice i on p.invoice = i.invoiceid where i.client = c.clientid and i.isdeleted = 0)
    < 0 
    and i.date < '2012-01-01'  -- THIS IS NOT PART OF THE SUBQUERY
THEN 
    (select ii.total from invoice ii where ii.client = c.clientid order by ii.invoiceid desc limit 1)  
ELSE 
    (select ifnull(sum(total), 0) from invoice i where i.client = c.clientid and i.isdeleted = 0) - (select ifnull(sum(p.amount), 0) from payment p inner join invoice i on p.invoice = i.invoiceid where i.client = c.clientid and i.isdeleted = 0) 
END as remaining,
case c.isactive+0
        when '1' then 'Stop'
        else 'Start' 
        end as Active
FROM client c 
ORDER BY clientname

Cosidering date是大多数数据库中的保留字，您可能需要根据需要将其封装起来。。。[date]或带有勾号。在大多数数据库中，共注日期是保留字，您可能需要根据需要将其封装。。。[日期]或带有勾号。