#1054 - “字段列表”中的未知列答案

【问题标题】：#1054 - Unknown column in 'field list'#1054 - “字段列表”中的未知列
【发布时间】：2014-11-04 06:32:26
【问题描述】：

我又遇到了另一个问题。我知道有很多与此问题相关的链接，但无法为我的查询找到确切的解决方案。这是我的查询：-

SELECT c.cust_id, c.cust_name, c.cust_mob, sum(CASE WHEN trans_type = 'Purchase' THEN total_amt ELSE 0 END) as purchase, sum(CASE WHEN trans_type = 'Sale' THEN total_amt ELSE 0 END) as sale, sum(ifnull(a.payment_amt,0)) as tot_pay, (purchase-(sale+sum(a.payment_amt))) as tot_torcv, ((sale+sum(a.payment_amt))-purchase) as tot_topay FROM bil_customers c 
    inner join bil_vendor_account a on(c.cust_id=a.vendor_id) 
    WHERE c.cust_catagory = '3' 
    group by cust_id 
    having ifnull(tot_torcv,0) between '0' and '100000' 
    order by a.sl_no

我不知道查询有什么问题，因为它抛出以下错误：-

1054 - “字段列表”中的未知列“购买”

请帮我解决问题。提前致谢！！

【问题讨论】：

你不能这样使用别名。

标签： mysql

【解决方案1】：

您的错误是，您将购买用作列，即使它是别名，您也可以改用它

未测试

SELECT c.cust_id, c.cust_name, c.cust_mob, @purchase :=sum(CASE WHEN trans_type = 'Purchase' THEN total_amt ELSE 0 END) as purchase, sum(CASE WHEN trans_type = 'Sale' THEN total_amt ELSE 0 END) as sale, sum(ifnull(a.payment_amt,0)) as tot_pay, (@purchase-(sale+sum(a.payment_amt))) as tot_torcv, ((sale+sum(a.payment_amt))-@purchase) as tot_topay FROM bil_customers c 
inner join bil_vendor_account a on(c.cust_id=a.vendor_id) 
WHERE c.cust_catagory = '3' 
group by cust_id 
having ifnull(tot_torcv,0) between '0' and '100000' 
order by a.sl_no

如果我错过了什么，请告诉我

【讨论】：

非常感谢@CodeSlayer。我用计算替换了购买和销售别名，它工作得很好。 :) 但是我可以知道为什么别名不能用作另一列吗？
别名和列名不起作用我不知道为什么可能是因为它们是动态数据，因此您需要将其存储在变量中以获取列的当前值。
既然我的回答解决了你的问题，你能把它标记为解决方案吗？

【解决方案2】：

您不能在 select 语句中使用别名 createtd 来计算其他列。你必须用计算替换别名

SELECT c.cust_id, c.cust_name, c.cust_mob, sum(CASE WHEN trans_type = 'Purchase' THEN total_amt ELSE 0 END) as purchase, sum(CASE WHEN trans_type = 'Sale' THEN total_amt ELSE 0 END) as sale, sum(ifnull(a.payment_amt,0)) as tot_pay, (sum(CASE WHEN trans_type = 'Purchase' THEN total_amt ELSE 0 END)-(sale+sum(a.payment_amt))) as tot_torcv, ((sale+sum(a.payment_amt))-sum(CASE WHEN trans_type = 'Purchase' THEN total_amt ELSE 0 END)) as tot_topay FROM bil_customers c 
    inner join bil_vendor_account a on(c.cust_id=a.vendor_id) 
    WHERE c.cust_catagory = '3' 
    group by cust_id 
    having ifnull(tot_torcv,0) between '0' and '100000' 
    order by a.sl_no

【讨论】：

【解决方案3】：

除了 CodeSlays 所写的内容之外，<expression> between '0' and '100000' 将无法按您的预期工作，因为它将执行字符串比较而不是数字比较（提醒：'9' > '10'，）。

【讨论】：