Question

我有一个State参数作为可选的存储过程，所以如果我通过状态它应该使用两个参数查询表，如果我没有传递状态参数我只需要用模板查询表参数。

我怎么能这样做？

这是我的存储过程：

CREATE PROCEDURE [dbo].[Get_TempName]
     @TemType varchar(50),
     @State varchar(50) = 'N/A'
AS
BEGIN
     SET NOCOUNT ON;

     SELECT 
         [TempType],
         [TempName],
         [State]
     FROM 
         [Template] WITH (NOLOCK) 
     WHERE
         TempType = @TempType 
         AND [State] = @State
END

Answer 1

Create[dbo].[Get_TempName]
  @TemType    varchar(50)
 ,@State    varchar(50) = NULL

AS
BEGIN
 SET NOCOUNT ON;

 SELECT 
   [TempType]
  ,[TempName]
  ,[State]

 FROM [Template]  WITH (NOLOCK) 
  where TempType = @TempType 
 and (([State] IS NULL) OR ([State] = @State))

 END

Answer 2

您可以OR条件使用Is Null条件。如果您不想在过滤器

中使用NULL，请在@state参数中传递

Create[dbo].[Get_TempName]
  @TemType    varchar(50)
 ,@State    varchar(50) 

AS
BEGIN
 SET NOCOUNT ON;

 SELECT 
   [TempType]
  ,[TempName]
  ,[State]

 FROM [Template]  WITH (NOLOCK) 
  where TempType = @TempType 
 and ([State] = @State or @state is null)

 END

VisitorParking

Answer 3

您可以在一个select语句中执行所有操作，但这可能会对性能产生负面影响。通常最好根据参数将其分成单独的选择。

Create[dbo].[Get_TempName]
@TemType    varchar(50)
,@State    varchar(50) 

AS
BEGIN
SET NOCOUNT ON;

IF(@State IsNull)
    SELECT 
    [TempType]
    ,[TempName]
    ,[State]
    FROM [Template]  WITH (NOLOCK) 
    where TempType = @TempType 
 ELSE
    SELECT 
    [TempType]
    ,[TempName]
    ,[State]
    FROM [Template]  WITH (NOLOCK) 
    where TempType = @TempType 
    and [State] = @State
END

在存储过程中有一个可选参数

3 个答案: