Question

我尝试创建一个返回varchar的函数，但我不能，因为我在里面使用CREATE TABLE，当我用一个过程创建它时，我无法返回值。

我想知道你是否有一些建议。

我这样做只是为了创建一个字符串，其中包含以“;”分隔的电子邮件所以我可以将所有“经理”邮件放在一个varchar中（对于收件人）。

ALTER procedure [dbo].[Manager_email]
AS
BEGIN
    declare @mails varchar (max),
            @number_of_mails int,
            @counter int
    set @counter=2
    create table #temp ( id int identity, email varchar(30))
    insert into #temp (email)
    select Email
    from hr.Employees
    where lower (EmpRole) like 'manager'
    set @number_of_mails=@@ROWCOUNT
    set @mails = (select email from #temp where id =1 ) + ';'
    while @counter <= @number_of_mails
    BEGIN
        set @mails = @mails + (select email from #temp where id =@counter ) + ';'
        set @counter = @counter+1
    END
    drop table #temp
    return cast (@mails as varchar (200))
END

Answer 1

你只能从程序中返回整数值，如果你想从程序中返回varchar值，那么在程序中使用输出变量就好了。

实施例

CREATE PROCEDURE Sales.uspGetEmployeeSalesYTD
@SalesPerson nvarchar(50),
@SalesYTD money OUTPUT
AS  

    SET NOCOUNT ON;
    SELECT @SalesYTD = SalesYTD
    FROM Sales.SalesPerson AS sp
    JOIN HumanResources.vEmployee AS e ON e.BusinessEntityID = sp.BusinessEntityID
    WHERE LastName = @SalesPerson;
RETURN

就像上面的过程从程序中返回@SalesYTD一样。

您可以在MSDN上查看完整帖子：Returning Data by Using OUTPUT Parameters

Answer 2

您可以使用功能

CREATE FUNCTION Manager_email ()
RETURNS varchar(max)
AS
BEGIN
    declare @email varchar(30)
    declare @emails varchar(max)

    set @emails = ''

    declare cur cursor for
    select Email
    from hr.Employees
    where lower (EmpRole) like 'manager'

    open cur

    fetch next from cur into @email

    while @@fetch_status = 0 
    begin
        set @emails = @emails + @email + ';'
        fetch next from cur into @email
    end

    close cur
    deallocate cur

    return @emails
END

Answer 3

您可以使用表变量而不是临时表。在这种情况下，您可以继续使用UDF。

返回varchar的过程

3 个答案: