功能问题？

Question

我做了一个没有参数的函数，但它不起作用是什么原因在这里输入图像描述

   CREATE FUNCTION x3()
returns varchar(max)
as
begin
    declare @ilk_isim varchar(50)
    declare @soy_isim varchar(50)
    declare @birlestir varchar(100)
    select @ilk_isim = adi from alici where id = 2
    select @soy_isim = adi from ilan_veren where id = 1
    select @birlestir = @ilk_isim+' '+@soy_isim

    return @birlestir
    end


select dbo.x3()

Answer 1

这适用于 SQL Server。 @在这里是变量声明所必需的。 SELECT .. INTO ..不适用于 SQL Server，使用变量赋值。

CREATE FUNCTION x3()
returns varchar(101)
begin
    declare @ilk_isim varchar(50);
    declare @soy_isim varchar(50);
    declare @birlestir varchar(101);

    select @ilk_isim = adi from alici where id = 2;
    select @soy_isim = adi from ilan_veren where id = 1;
    select @birlestir = CONCAT(@ilk_isim, ' ', @soy_isim);

    return @birlestir;
end

select dbo.x3()

Answer 2

您正在合并 MySql 和 Sql Server。

尝试这个：

CREATE FUNCTION x3() RETURNS VARCHAR(101)
BEGIN
   DECLARE @ilk_isim VARCHAR(50);
   DECLARE @soy_isim VARCHAR(50);
   SELECT adi INTO @ilk_isim FROM alici WHERE ID = 2;
   SELECT adi INTO @soy_isim FROM ilan_veren WHERE ID = 1;
   RETURN CONCAT(@ilk_isim, ' ', @soy_isim);
END;

SELECT x3();

有关 FUNCTIONS 的信息，请参阅此链接： https : //www.geeksforgeeks.org/mysql-creating-stored-function/

有关 CONCAT 信息的链接： https : //www.w3resource.com/mysql/string-functions/mysql-concat-function.php

有关 SELECT INTO VARIABLE 信息的链接： http : //www.mysqltutorial.org/mysql-select-into-variable/