SQL Server进阶（十五）常用函数

FROM
WHERE
GROUP BY
HAVING
SELECT
ORDER BY

                           IF EXISTS (SELECT 1  FROM  TableName WHERE  UserCode = @UserCode)
                              BEGIN
                                  UPDATE TableName
                                  SET    NotPushBeginTime = @NotPushBeginTime,
                                         NotPushEndTime = @NotPushEndTime
                                  WHERE  UserCode = @UserCode
                              END
                            ELSE
                              BEGIN
                                  INSERT INTO TableName
                                              (UserCode,
                                               NotPushBeginTime,
                                               NotPushEndTime,
                                               CreateTime)
                                  VALUES     (@UserCode,
                                              @NotPushBeginTime,
                                              @NotPushEndTime,
                                              Getdate())
                             END

下面是一个不带输入参数的表值函数
create function tvpoints()
returns table
as 
return
(
select * from tb_users
);

对于多语句表值函数，在 BEGIN...END 语句块中定义的函数体包含一系列 Transact-SQL 语句，这些语句可生成行并将其插入将返回的表中。
以下示例创建了一个表值函数.
create function tvpoints()
returns @points table (x float, y float)
as begin
insert @points values(1,2);
insert @points values(3,4);
return;
end

CREATE FUNCTION FUN_DataFormat (@strDate datetime)  
RETURNS varchar(20)  AS  
BEGIN 
    
    declare @date varchar(20)
      set @date = DATENAME(YY,@strDate)+‘年‘+Convert(VARCHAR,MONTH(@strDate))+‘月‘+Convert(VARCHAR,DAY(@strDate))+‘日‘
    return @date
END