Question

CREATE PROCEDURE findlist @comedianname1 nvarchar(30),@comedianname2 nvarchar(30)
AS
SELECT comedian 
FROM Comedian
if @comedianname2!=null
begin
WHERE comedian! = @comedianname1 and comedian! = @comedianname2
end
else
begin
WHERE comedian! = @comedianname1
end
GO

我收到此错误：消息156，级别15，状态1，程序搜索列表，第7行关键字'WHERE'附近的语法不正确。

Answer 1

您无法在选择中使用IF。你可以在你的情况下这样做：

SELECT comedian 
FROM Comedian
WHERE
    comedian! = @comedianname1 AND
    comedian! = ISNULL(@comedianname2, comedian!)

它做什么？如果将comedian!与@comedianname1进行比较，如果@comedianname2不为空，则会将comedian!与@comedianname2进行比较。否则，它会将comedian!与comedian!进行比较，true始终为{{1}}。

Answer 2

您需要使用以下查询

SELECT comedian 
FROM Comedian
WHERE comedian! = @comedianname1 and (comedian! = @comedianname2 OR @comedianname2 IS NULL)

Answer 3

试试这个

CREATE PROCEDURE findlist @comedianname1 nvarchar(30),@comedianname2 nvarchar(30)
AS
  SELECT comedian 
  FROM Comedian
  WHERE (comedian! = @comedianname1 and comedian! = @comedianname2) OR (comedian! = @comedianname1)
GO

如何在带有where子句的sql server中使用if else

3 个答案: