Question

我有以下查询：

select      count(L.ID)
from        LA inner join L on (LA.leadid = L.ID)
where       L.status = 5
and         L.city = "cityname"
and         Date(LA.Datetime) < Date_Sub(Now(), INTERVAL 6 MONTH);

查找特定城市中状态为5且年龄超过6个月（日期存储在洛杉矶）的记录。这将返回大约4k的结果。我想在每个记录上将状态值更新为1，因此我的更新如下所示：

update      L, LA
set         L.status = 1
where       L.status = 5 
and         L.city = "cityname" 
and         Date(LA.SomeDatetime) < Date_Sub(Now(), INTERVAL 6 MONTH);

但是它会停止并锁定数据库。我怀疑存在问题，因为没有连接，但我尝试了类似的事情：

update      L, LA
from        L inner join LA on (L.OID = LA.leadid)
set         L.status = 1
where       L.status = 5 
and         L.syscity = "cityname" 
and         Date(LA.SomeDatetime) < Date_Sub(Now(), INTERVAL 6 MONTH);

它显然无效，因为更新中没有'from'。

编辑＆gt;我正在使用MySQL

Answer 1

update      L
set         L.status = 1
where       L.status = 5 
and         L.city = "cityname" 
and         EXISTS (
  select * from LA 
  where Date(LA.SomeDatetime) < Date_Sub(Now(), INTERVAL 6 MONTH)
  and LA.leadid = L.ID
)

Answer 2

对于MySQL，您可以使用旧的连接语法：

UPDATE  l, la
SET     l.status = 1
WHERE   l.status = 5
  AND   l.city = "cityname"
  AND   la.leadid = l.id
  AND   DATE(la.datetime) < DATE_SUB(NOW(), INTERVAL 6 MONTH)

Answer 3

我会这样做：

update L
set status = 1
from LA
where L.OID = LA.leadid
and L.status = 5
and L.syscity = "cityname"
and Date(LA.SomeDatetime) < Date_Sub(Now(), INTERVAL 6 MONTH)

另见：

SQL update from one Table to another based on a ID match

Answer 4

在SQL Server 2005中，这将起作用：

Update L
   set L.status = 1
from
   L
   --
   JOIN LA
      on (LA.leadid = L.id)
where
   L.status = 5
   and L.city = "cityname"
   and Date(LA.Datetime) < Date_Sub(Now(), INTERVAL 6 MONTH);

如何在更新时连接表

4 个答案: