Question

我有这个过程作为T-SQL脚本的一部分被删除/创建 - 想法是插入父记录，并将其ID输出到调用者，以便我可以插入<使用该ID的em> children 记录。

if exists (select * from sys.procedures where name = 'InsertCategory')
    drop procedure dbo.InsertCategory;
go

create procedure dbo.InsertCategory
     @code nvarchar(5)
    ,@englishName nvarchar(50)
    ,@frenchName nvarchar(50)
    ,@timestamp datetime = null
    ,@id int output
as begin

    if @timestamp is null set @timestamp = getdate();

    declare @entity table (_Id int, EntityId uniqueidentifier);
    declare @entityId uniqueidentifier;

    if not exists (select * from dwd.Categories where Code = @code)
    insert into dwd.Categories (_DateInserted, Code, EntityId) 
        output inserted._Id, inserted.EntityId into @entity
        values (@timestamp, @code, newid());
    else
        insert into @entity
        select _Id, EntityId from dwd.Categories where Code = @code;

    set @id = (select _Id from @entity);
    set @entityId = (select EntityId from @entity);

    declare @english int;
    set @english = (select _Id from dbo.Languages where IsoCode = 'en');

    declare @french int;
    set @french = (select _Id from dbo.Languages where IsoCode = 'fr');

    exec dbo.InsertTranslation @entityId, @english, @englishName, @timestamp;
    exec dbo.InsertTranslation @entityId, @french, @frenchName, @timestamp;

end
go

然后在脚本中稍微向下调用它：

declare @ts datetime;
set @ts = getdate();

declare @categoryId int;

exec dbo.InsertCategory 'C1', 'Category1', 'Catégorie1', @ts, @categoryId;
exec dbo.InsertSubCategory 'SC1', @categoryId, 'Description (EN)', 'Description (FR)', @ts

当我 debug 脚本并逐行执行时，我可以看到dbo.InsertCategory正确地分配了@id输出参数，脚本看作{{1}问题是@categoryId总是@categoryId，因此我没有将任何内容插入null。

我做错了什么？

Answer 1

您需要在调用过程时将@categoryId参数称为OUTPUT，否则它不会返回值。像这样调用这个程序

exec dbo.InsertCategory 'C1', 'Category1', 'Catégorie1', @ts, @categoryId OUTPUT;

示例

CREATE PROCEDURE Procd (@a INT, @b INT output)
AS
  BEGIN
      SELECT @b = @a
  END

DECLARE @new INT

EXEC Procd 1,@new 
SELECT @new -- NULL

EXEC Procd 1,@new OUTPUT 
SELECT @new -- 1

Out参数已正确分配，但调用者只看到NULL。线索？

1 个答案: