SQL Server存储过程中的返回值

Question

I have a stored procedure that has an if statement in it. If the number of rows counted is greater than 0 then it should set the only output parameter @UserId to 0

However it only returns a value in the second part of the query.

@EmailAddress varchar(200),
@NickName varchar(100),
@Password varchar(150),
@Sex varchar(50),
@Age int,
@EmailUpdates int,
@UserId int OUTPUT
IF 
    (SELECT COUNT(UserId) FROM RegUsers WHERE EmailAddress = @EmailAddress) > 0
    BEGIN
        SET @UserId = 0
    END
ELSE
    BEGIN
        INSERT INTO RegUsers (EmailAddress,NickName,PassWord,Sex,Age,EmailUpdates) VALUES (@EmailAddress,@NickName,@Password,@Sex,@Age,@EmailUpdates)
        SELECT SCOPE_IDENTITY()
    END

END

Answer 1

You can either do 1 of the following:

Change:

SET @UserId = 0 to SELECT @UserId

This will return the value in the same way your 2nd part of the IF statement is.

---

Or, seeing as @UserId is set as an Output, change:

SELECT SCOPE_IDENTITY() to SET @UserId = SCOPE_IDENTITY()

---

It depends on how you want to access the data afterwards. If you want the value to be in your result set, use SELECT . If you want to access the new value of the @UserId parameter afterwards, then use SET @UserId

---

Seeing as you're accepting the 2nd condition as correct, the query you could write (without having to change anything outside of this query) is:

@EmailAddress varchar(200),
@NickName varchar(100),
@Password varchar(150),
@Sex varchar(50),
@Age int,
@EmailUpdates int,
@UserId int OUTPUT
IF 
    (SELECT COUNT(UserId) FROM RegUsers WHERE EmailAddress = @EmailAddress) > 0
    BEGIN
        SELECT 0
    END
ELSE
    BEGIN
        INSERT INTO RegUsers (EmailAddress,NickName,PassWord,Sex,Age,EmailUpdates) VALUES (@EmailAddress,@NickName,@Password,@Sex,@Age,@EmailUpdates)
        SELECT SCOPE_IDENTITY()
    END

END

Answer 2

I can recommend make pre-init of future index value, this is very usefull in a lot of case like multi work, some export etc

just create additional User_Seq table: with two fields: id Uniq index and SeqVal nvarchar(1)

and create next SP, and generated ID value from this SP and put to new User row!

CREATE procedure [dbo].[User_NextValue]
as
begin
    set NOCOUNT ON


    declare @existingId int = (select isnull(max(UserId)+1, 0)  from dbo.User)

    insert into User_Seq (SeqVal) values ('a')
    declare @NewSeqValue int = scope_identity()     

    if @existingId > @NewSeqValue 
    begin  

        set identity_insert User_Seq  on
        insert into User_Seq (SeqID) values (@existingId)     
        set @NewSeqValue = scope_identity()     
    end

    delete from User_Seq WITH (READPAST)

return @NewSeqValue

end

Answer 3

Try to call your proc in this way:

DECLARE @UserIDout int

EXEC YOURPROC @EmailAddress = 'sdfds', @NickName = 'sdfdsfs', ..., @UserId = @UserIDout OUTPUT

SELECT @UserIDout 

Answer 4

@EmailAddress varchar(200),
@NickName varchar(100),
@Password varchar(150),
@Sex varchar(50),
@Age int,
@EmailUpdates int,
@UserId int OUTPUT
DECLARE @AA INT
SET @AA=(SELECT COUNT(UserId) FROM RegUsers WHERE EmailAddress = @EmailAddress)

IF @AA> 0
    BEGIN
        SET @UserId = 0
    END
ELSE
    BEGIN
        INSERT INTO RegUsers (EmailAddress,NickName,PassWord,Sex,Age,EmailUpdates) VALUES (@EmailAddress,@NickName,@Password,@Sex,@Age,@EmailUpdates)
        SELECT SCOPE_IDENTITY()
    END

END