SQL左联接并显示结果

Question

欢迎，

我有2个表int_client和int_client_bank 。

在第一重要列中： client_id, firstname, lastname, country, email, status 。 在第二个中： client_id, status 。

我需要显示所有记录：第一列的firstname, lastname, country, e-mail WHERE status='25' （第二张表中出现client_id那些记录除外）。 如果出现在第二个表中的client_id正在跳过第一列的状态，并且在secound表中仅显示status='25' 。

SB能帮我吗？

编辑：

SELECT firstname, lastname, country, email, COALESCE(b.status, a.status) status
 FROM int_client a
 LEFT JOIN int_client_back b USING (client_id)
 WHERE 
  (b.status IS NULL and a.status='25')
  OR b.status IS NOT NULL;

这是很好的代码，但是我只需要在B列中显示状态为“ 25”的记录，如果a.client_id！= b.client_id，我需要在A列中显示状态为“ 25”的记录

SB，帮忙吗？

Answer 1

使用COALESCE() LEFT JOIN应该执行以下操作：

SELECT firstname, lastname, country, email, COALESCE(b.status, a.status) status
 FROM int_client a
 LEFT JOIN int_client_back b USING (client_id)
 WHERE 
  (b.status IS NULL and a.status='25')
  OR b.status IS NOT NULL;

Answer 2

此选择查询应工作：

SELECT t1.first_name,t1.last_name,t1.country,t1.email FROM int_client AS t1, int_client_bank AS t2
WHERE t1.client_id = t2.client_id AND t1.status = 25;

Answer 3

下面的查询将为您解决问题。

SELECT client_id, firstname, lastname, country, email, status FROM int_client as ic LEFT JOIN int_client_back icb ON ic.client_id=icb.client_id WHERE ic.status=25

Answer 4

如果我理解正确，则需要int_client中状态为“ 25”的所有记录。 但是，如果int_client_bank存在另一个状态，那么您想显示该状态。

select c.first_name, c.last_name, c.email, c.country,
       coalesce(cb.status, c.status)
from int_client c left join
     int_client_bank cb
     on cb.client_id = c.client_id
where c.status = 25;

Answer 5

SELECT DISTINCT firstname, lastname, country, email, 
a.status as status_a, b.status as status_b, if(b.status is NULL, a.status, b.status) as final_status
 FROM int_client a
 LEFT JOIN int_client_bank b USING (client_id)
 WHERE 
  if(b.status is NULL, a.status, b.status) = '25'