查询从两个查询中获取带有特殊标志的记录

Question

我有两张表如下。我需要一个如下所示的结果。

table1

id    name   
-----------------
1     john
2     raju
3     gopi
4     sarath

table2

userid     status
------------------
1          E
3          E


I need a query to select record from table like following

id    name      flag
---------------------
1     john      In
2     raju      Out
3     gopi      In
4     sarath    Out

如果状态为“E”的用户在结果集中显示为“In”，其他人则显示为“Out”

Answer 1

简单的连接和案例

SELECT table1.*, 
   CASE WHEN table2.status='E' THEN 'In' ELSE 'Out' END 
FROM table1 LEFT JOIN table2 on table1.id = table2.userid;

Answer 2

我认为以下SQL对您有用。

select table1.id, table1.name, CASE WHEN table2.status='E' THEN 'In' ELSE 'Out' END 
from table1 JOIN table2 on table1.id = table2.userid;