sql server 純量值函式執行個體與不能調用原因分析

sql server 純量值函式執行個體與不能調用原因分析
--純量值函式

set ansi_nulls on
go
set quoted_identifier on
go
-- =============================================
-- author: <author,,name>
-- create date: <create date, ,>
-- description: <description, ,>
-- =============================================
create function <scalar_function_name, sysname, functionname>
(
-- add the parameters for the function here
<@param1, sysname, @p1> <data_type_for_param1, , int>
)
returns <function_data_type, ,int>
as
begin
-- declare the return variable here
declare <@resultvar, sysname, @result> <function_data_type, ,int>

-- add the t-sql statements to compute the return value here
select <@resultvar, sysname, @result> = <@param1, sysname, @p1>

-- return the result of the function
return <@resultvar, sysname, @result>

end

用 ms sql 純量值函式，應該在函數前面加上 "dbo."，否則會報 “不是可以識別的 內建函數名稱”錯誤。例如

  

  declare @whichdb tinyint;
    select @whichdb = user_getwhichdb(1);--看看是哪個資料庫教程的

=================================================

--純量值函式

alter function [dbo].[user_getwhichdb]
(
    @userid int = 0
)
returns tinyint
with execute as caller
as
begin
    declare @whichdb tinyint;
    set @whichdb = 1;
    if @userid >= 115098
        set @whichdb = 2;
   
    return (@whichdb);
end