Question

sql server 存储过程 语句

CREATE PROCEDURE [dbo].[P_GetTrainListByPlace]
-- Add the parameters for the stored procedure here
@vc_FromPlace varchar,
@vc_ToPlace varchar
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;

-- Insert statements for procedure here
if(@vc_FromPlace is null)
begin
SELECT * from [tb_Train] where vc_FromPlace =@vc_FromPlace
end
else if(@vc_ToPlace is null)
begin
SELECT * from [tb_Train] where vc_ToPlace =@vc_ToPlace
end
else
begin
SELECT * from [tb_Train] where (vc_FromPlace =@vc_FromPlace) and (vc_ToPlace =@vc_ToPlace)
end

END

======================================================
请看看我写的对不？

为什么执行了却没有显示数据？

Answer 1

格式没错
if(“@vc_FromPlace is null”)
begin
SELECT * from [tb_Train] where“ vc_FromPlace =@vc_FromPlace”
end --如果你的变量名为空，你还要查找变量满足该变量的的数据，当然没数据显示了
以下那个也一样