我有一个问题,我试图将数据从一个表合并到另一个表中。在SQL中使用合并合并两个表
除了目标需要在第一列上有主键之外,源表和目标表是相同的。
的数据输入和预期的结果如下:
data in Desired results
c1 c2 c3 c1 c2 c3
+--+--+--+ +--+------+------+
1 A x 1 A B C x y
2 B z 2 B C z
3 A z 3 A z x y
1 A y +--+------+------+
3 A y
1 B x
2 C z
1 C x
3 A x
1 A x
+--+--+--+
我初始化表...
CREATE TABLE s (c1 char(2), c2 char(8), C3 char(8))
INSERT INTO s VALUES
('1','A','x'), ('2','B','z'), ('3','A','z'),
('1','A','y'), ('3','A','y'), ('1','B','x'),
('2','C','z'), ('1','C','z'), ('3','A','x'),
('1','A','x')
CREATE TABLE d (c1 char(2) PRIMARY KEY, c2 char(8), C3 char(8))
我可以得到它使用游标工作...
DECLARE @c1 Char(2)
DECLARE @c2 char(8)
DECLARE @C3 char(8)
DECLARE cur CURSOR FOR SELECT c1, c2, C3 FROM s
OPEN cur
FETCH NEXT FROM cur INTO @c1, @c2, @C3
WHILE @@FETCH_STATUS = 0
BEGIN
UPDATE d SET
c2 = (CASE WHEN CHARINDEX(RTRIM(@c2), c2) > 0 THEN c2 ELSE SUBSTRING(RTRIM(c2) + ' ' + @c2, 1, 8) END),
c3 = (CASE WHEN CHARINDEX(RTRIM(@c3), c3) > 0 THEN c3 ELSE SUBSTRING(RTRIM(c3) + ' ' + @c3, 1, 8) END)
WHERE c1 = @c1
IF @@ROWCOUNT = 0
BEGIN
INSERT INTO d (c1, c2, c3)
VALUES (@c1, @c2, @c3)
END
FETCH NEXT FROM cur INTO @c1, @c2, @c3
END
CLOSE cur
DEALLOCATE cur
但我不能合并工作...
错误:Vi主键约束'PK__d__3213663B03BB8E22'的关联。无法在对象'dbo.d'中插入重复键。重复的键值是(1)。
MERGE INTO d USING s
ON (s.c1 = d.c1)
WHEN MATCHED THEN
UPDATE SET
c2 = (CASE WHEN CHARINDEX(RTRIM(s.c2), d.c2) > 0 THEN d.c2 ELSE SUBSTRING(RTRIM(d.c2) + ' ' + s.c2, 1, 8) END),
c3 = (CASE WHEN CHARINDEX(RTRIM(s.c3), d.c3) > 0 THEN d.c3 ELSE SUBSTRING(RTRIM(d.c3) + ' ' + s.c3, 1, 8) END)
WHEN NOT MATCHED THEN
INSERT (c1, c2, c3) VALUES (s.c1, s.c2, s.c3);
有没有办法比再逐行多一点风度做到这一点?
感谢您的帮助!
哪个RDBMS是这样的?请添加一个标签来指定您是使用'mysql','postgresql','sql-server','oracle'还是'db2' - 或者其他的东西。 – 2015-03-31 18:36:47
@marc_s - 语法清楚地说它是'sql server' – 2015-03-31 18:44:53