当TVP不包含任何行时，使用输入TVP参数进行单个SQL查询

Question

Anyone knows a kind of this trick

CREATE PROCEDURE [pr_GetFinDoc]
    @id UNIQUEIDENTIFIER NULL
AS
BEGIN
    SELECT f.*
    FROM [dbo].[FinDocument] f     --id column is primary key
    WHERE @id is null or f.id = @id
END

So, the procedure above returns either single FinDoc or all FinDocs . It depends on whether the id was sent or not.

Just a single query.

So i need something like that but for tvp parameter.

It's my tvp parameter - just array of uniqueidentifier values

CREATE TYPE [dbo].[GuidList] AS TABLE(
    [Id] [uniqueidentifier] NOT NULL,
    PRIMARY KEY CLUSTERED 
(
    [Id] ASC
)WITH (IGNORE_DUP_KEY = OFF)
)

And my stored procedure:

CREATE PROCEDURE [pr_GetFinDoc]
    @id_list [dbo].[GuidList] READONLY
AS
BEGIN

    IF EXISTS (SELECT 1 FROM @id_list)
        BEGIN
            SELECT f.*
            FROM
            @id_list filter 
                INNER JOIN [dbo].[FinDocument] f 
                    ON f.id = filter.Id
        END
    ELSE
        BEGIN
            SELECT f.*
            FROM [dbo].[FinDocument] f
        END
END

Is there a way to change the code of SP with tvp input parameter to single query ?

Answer 1

You can use IN instead. This gives you the flexibility to use more complex logic:

select f.*
from FinDocument f
where f.id in (select id from @id_list) or
      not exists (select 1 from @id_list);

Note that these methods (and yours) are not necessarily efficient. The if logic will probably compile using an index on id . Often if the queries are complex, it is better to either force a re-compile or use dynamic SQL (and force a re-compile) because of SQL Server compiles queries the first time the stored procedure is invoked. And the query plan may not be optimal for all parameter choices.