从select中的子查询生成的别名字段

Question

我有一个像这样的选择查询：

SELECT 
emp_des_company as 'Company', 
(SELECT pav_des_valor FROM slt_pergunta_avaliacao pa, slt_avaliacao a WHERE pa.pav_idn_pergunta = 393 AND c.cas_idn_avaliacao = a.avl_idn_avaliacao)
FROM slt.case
...

我如何将此子查询别名如下：

SELECT 
emp_des_company as 'Company', 
(SELECT pav_des_valor FROM slt_pergunta_avaliacao pa, slt_avaliacao a WHERE pa.pav_idn_pergunta = 393 AND c.cas_idn_avaliacao = a.avl_idn_avaliacao) as (SELECT per_des_descricao WHERE per_idn_pergunta = 393) 
FROM slt.case
...

提前致谢。

Answer 1

您不能简单地在静态SQL中使用列别名的动态值。 您将不得不使用固定值：AS column_name

一种可以实现的方法是动态创建查询，查看prepared statements。