的SQL Server 2008：更新基于环路上的另一台

Question

一个专栏中，我有两个表：

create table tblA (Pid int, Ltype varchar(2), upcoming_Ltype varchar(2)) 
insert into tblA (pid, ltype) 
values 
(123, 'A1'), 
(123, 'C2'), 
(567, 'B1'), 
(457, 'A1') 

create table tblB (Pid int, Ltype varchar(2), isactive bit) 
insert into tblB (Pid, Ltype, isactive) 
values 
(123,'A1',1), 
(123,'C2',1), 
(123,'B1',1), 
(123,'E2',1), 

(567,'A1',1), 
(567,'C2',1), 
(567,'B1',1), 
(567,'E2',1), 

(457,'A1',1), 
(457,'C2',0), 
(457,'B1',1), 
(457,'E2',1) 

这里应注意，在TBLB，L-型永远是A1，C2，B1和E2为了让每一个的Pid 。现在，我想基于下一isactive从TBLA填充upcoming_Ltype = 1 L-型从TBLB

预期结果：

TBLA：

(123, 'A1',C2), 
(123, 'C2',B1), 
(567, 'B1',E2), 
(457, 'A1',B1) <-- skipping C2 

这是我的工作（不工作）：

UPDATE tblA 
SET upcoming_Ltype = 
(
    SELECT Ltype 
    FROM tblB 
    WHERE tblA.Pid = tblB.Pid 
    AND tblB.isActive = 1 
    AND tblB.Ltype > tblA.Ltype 
) 

Answer 1

Pune是Bhupinder Singh吗？

如果您创建一个选择查询来计算值，那么你可以加入到它的更新

use tempdb 
CREATE Table #order_lkp 
(Ltype varchar(2) not null UNIQUE, sortorder int identity) 

INSERT #order_lkp VALUES('A1'), ('C2'), ('B1'), ('E2') 

create table tblA (Pid int, Ltype varchar(2), upcoming_Ltype varchar(2)) 
insert into tblA (pid, ltype) 
values 
(123, 'A1'), 
(123, 'C2'), 
(567, 'B1'), 
(457, 'A1') 

create table tblB (Pid int, Ltype varchar(2), isactive bit) 
insert into tblB (Pid, Ltype, isactive) 
values 
(123,'A1',1), 
(123,'C2',1), 
(123,'B1',1), 
(123,'E2',1), 

(567,'A1',1), 
(567,'C2',1), 
(567,'B1',1), 
(567,'E2',1), 

(457,'A1',1), 
(457,'C2',0), 
(457,'B1',1), 
(457,'E2',1) 
GO 
WITH UPCOMING_LKP AS 
(
SELECT find_upcoming_sortorder.Pid, find_upcoming_sortorder.Ltype, 
o.Ltype AS upcoming_Ltype 
FROM 
(
SELECT 
ta.Pid, 
ta.Ltype, 
ta.sortorder 
,MIN(tb.sortorder) 
AS upcoming_sortorder 
FROM 
(SELECT tblA.Ltype,tblA.Pid,sortorder FROM tblA JOIN #order_lkp ON tblA.Ltype = #order_lkp.Ltype) ta 
LEFT JOIN 
(SELECT tblB.Ltype,tblB.Pid,sortorder FROM tblB JOIN #order_lkp ON tblB.Ltype = #order_lkp.Ltype WHERE tblB.isactive <> 0) tb 
ON 
ta.Pid= tb.Pid 
AND tb.sortorder > ta.sortorder 
GROUP BY ta.Pid, ta.Ltype 
,ta.sortorder 
) find_upcoming_sortorder 
JOIN #order_lkp o ON o.sortorder = find_upcoming_sortorder.upcoming_sortorder 
) 


UPDATE a 
SET a.upcoming_Ltype = lkp.upcoming_Ltype 
FROM tblA a 
JOIN UPCOMING_LKP lkp ON a.Pid = lkp.Pid AND a.Ltype = lkp.Ltype 


GO 
DROP table tblA ; 
GO 
DROP table tblB; 
GO 
DROP Table #order_lkp