USE pubs
IF EXISTS (SELECT name FROM sysobjects
WHERE name = \'au_info\' AND type = \'P\')
DROP PROCEDURE au_info
GO
USE pubs
GO
CREATE PROCEDURE au_info
@lastname varchar(40),
@firstname varchar(20)
AS
SELECT au_lname, au_fname, title, pub_name
FROM authors a INNER JOIN titleauthor ta
ON a.au_id = ta.au_id INNER JOIN titles t
ON t.title_id = ta.title_id INNER JOIN publishers p
ON t.pub_id = p.pub_id
WHERE au_fname = @firstname
AND au_lname = @lastname
GO
au_info 存储过程可以通过以下方法执行：
EXECUTE au_info \'Dull\', \'Ann\'
执行该存储过程的时候必须2个参数都要填写。但是我有一个需求就是：我只输入一个参数，这个存储过程该怎么改？即我执行的时候，[email protected]@lastname
------解决方案--------------------
可以这样,存储过程的参数仍然使用两个参数,调用的时候,可以传递NULL值,例如:
- SQL code
EXECUTE au_info 'firstname',NULL--或者EXECUTE au_info NULL,'lastname'
------解决方案--------------------
如果一定要用一个参数,就将存储过程改成如下:
- SQL code
CREATE PROCEDURE au_info @name varchar(40) AS SELECT au_lname, au_fname, title, pub_name FROM authors a INNER JOIN titleauthor ta ON a.au_id = ta.au_id INNER JOIN titles t ON t.title_id = ta.title_id INNER JOIN publishers p ON t.pub_id = p.pub_id WHERE au_fname = @name ORageCount
------解决方案--------------------
下面的方法当 EXECUTE au_info 'firstname' 执行时，可以成功，[email protected]，所以想要 @firstname 复制，只能EXECUTE au_info null, 'lastname'这样
- SQL code
CREATE PROCEDURE au_info @lastname varchar(40)=null, @firstname varchar(20)=null AS SELECT au_lname, au_fname, title, pub_name FROM authors a INNER JOIN titleauthor ta ON a.au_id = ta.au_id INNER JOIN titles t ON t.title_id = ta.title_id INNER JOIN publishers p ON t.pub_id = p.pub_id WHERE au_fname = @firstname AND au_lname = @lastname
------解决方案--------------------
很简单.我假设,你存储过程的两个参数为 @p1,@p2
那么依具你存储过程中的写法,也有不同的写法.
- SQL code
--1,若是采用动态语句declare @sql varchar(1000)set @sql='select * from tb where 1=1 'if @p1 is not null set @[email protected] + ' and field1=' + @p1if @p2 is not null set @[email protected] + ' and field2=' + @p2--2,若是采用的非动态语句select * from tb where field1=case when @p1 is null then field1 else @p1 end and field2=case when @p2 is null then field2 else @p2 end
------解决方案--------------------
- SQL code
CREATE PROCEDURE au_infoge