我想使用存储过程准备动态select with join和select with union语句。对此我有
以下数据。
我有两张桌子：
表：Test1
select * from test1;
a b
------
A B
C D
E F
表：Test1
select * from test2;
a b
------
A B
C D
注意：现在我想将Joins和Union同时应用于这些表格（可能还有更多表格）
存储过程。我创建了演示存储过程，如下所示：
CREATE PROCEDURE Pro_Test
@Columns VARCHAR(100), --Columns to display
@Tables VARCHAR(1000), --Two or More tables names may pass here
@JoinORUnion VARCHAR(50), --Join or Union the tables
@IfJoinOnColumn VARCHAR(50) ---If join has pass then ON which column
AS
DECLARE @query VARCHAR(MAX)
IF @JoinORUnion = 'Inner Join'
BEGIN
SET @query = ''; ---Here want to prepare select with join statement
EXEC(@query);
END
ELSE IF @JoinORUnion = 'Union all'
BEGIN
SET @query = ''; ---Here want to prepare select with union statement
EXEC(@query);
END
GO
如果我通过：
EXECUTE Pro_Test
@Columns = 'a,b',
@Tables = 'Test1,Test2',
@JoinORUnion = 'Inner Join',
@IfJoinOnColumn = 'a';
然后声明应该是：
select test1.a,test1.b from test1
INNER JOIN
test2 ON test1.a = test2.a;
结果：
a b
------
A B
C D
如果我通过：
EXECUTE Pro_Test
@Columns = 'a,b',
@Tables = 'Test1,Test2',
@JoinORUnion = 'Union all',
@IfJoinOnColumn = '';
然后声明应该是：
select a,b from test1
union all
select a,b from test2
结果：
a b
------
A B
C D
E F
A B
C D