Question

我有这个简单的查询

SELECT * from switch_person where PTPK = (
SELECT PK from projects where TeamLead  = 1 and status = 1)

它正确显示了swith_person列。另外，我想显示projects表格列。子查询表“projects”包括我要显示的列和switch_person列。这可能吗？

Answer 1

使用join代替子查询：

SELECT * 
from switch_person 
join project on PTPK = PK
where TeamLead  = 1 and status = 1

Answer 2

为了选择多个列，连接到派生表而不是使用子查询，然后您可以选择多个派生表列：

SELECT x.PK, x.Col1, x.Col2, ...
from switch_person 
INNER JOIN
(
   SELECT PK, Col1, Col2
   FROM projects 
   WHERE TeamLead  = 1 and status = 1
) x
ON PTPK = x.PK;

如何显示子查询列

2 个答案: