Create FUNCTION Funtion_name
(  --这里定义传入参数以及类型
)
RETURNS TABLE
AS
RETURN
(--这里直接写查询语句，返回结果就是查询语句的结果集
)
GO

CREATE FUNCTION F_BConversion
(  @NUM1 INT,@NUM2 INT
)
RETURNS TABLE
AS
RETURN
(SELECT @NUM1+@NUM2 Addition,@NUM1-@NUM2 Subtration,@NUM1*@NUM2 Multiplication,@NUM1/@NUM2 Division
)
GO

CREATE FUNCTION Funtion_name
(--这里定义传入参数及类型
)
RETURNS
@table_name TABLE
(--这里定义@table_name的列名
)
AS
BEGIN--这里写sql语句并且将最终需要返回的结果集塞到@table_name 这张表里面RETURN
END
GO

ALTER FUNCTION F_TConversion
(@NUM INT
)
RETURNS
@t_table TABLE
([Binary] varchar(64),Octal varchar(16),Hexadecimal varchar(8)
)
AS
BEGINDECLARE @RESULT2 VARCHAR(500)='',@RESULT8 VARCHAR(500)='',@RESULT16 VARCHAR(500)=''; WITH CTE AS( SELECT @NUM/2 D2,@NUM%2 S2,@NUM/8 D8,@NUM%8 S8,@NUM/16 D16,@NUM%16 S16,1 [INDEX] UNION ALL SELECT D2/2 , D2%2,D8/8 , D8%8,D16/16 , D16%16,[INDEX]+1 FROM CTE WHERE D2>0 ) SELECT @RESULT2+=CAST(S2 AS VARCHAR(1)),@RESULT8+=CASE WHEN D8=0 AND S8=0 THEN '' ELSE CAST(S8 AS VARCHAR(1)) END,@RESULT16+=CASE WHEN D16=0 AND S16=0 THEN ''ELSE CASE CAST(S16 AS VARCHAR(5))WHEN '10' THEN 'A' WHEN '11' THEN 'B' WHEN '12' THEN 'C' WHEN '13' THEN 'D' WHEN '14' THEN 'E' WHEN '15' THEN 'F' ELSE CAST(S16 AS VARCHAR(5))ENDENDFROM CTE ORDER BY [INDEX] DESCINSERT INTO @t_tableSELECT @RESULT2,@RESULT8,@RESULT16RETURN
END
GO

CREATE FUNCTION function_name
(--这里定义传入参数及类型
)
RETURNS --这里需要定义返回值的类型
AS
BEGIN--定义返回值--写sql逻辑--返回返回值
END
GO

CREATE FUNCTION F_Conversion
(@NUM INT,@TYPE INT
)
RETURNS VARCHAR(100)
AS
BEGINDECLARE @RESULT VARCHAR(500)=''; WITH CTE AS( SELECT @NUM/@type D,@NUM%@type S,1 [INDEX] UNION ALL SELECT D/@type , D%@type,[INDEX]+1 FROM CTE WHERE D>0 ) SELECT @RESULT+=CASE CAST(S AS VARCHAR(5)) WHEN '10' THEN 'A' WHEN '11' THEN 'B' WHEN '12' THEN 'C' WHEN '13' THEN 'D' WHEN '14' THEN 'E' WHEN '15' THEN 'F' ELSE CAST(S AS VARCHAR(5)) END FROM CTE ORDER BY [INDEX] DESC RETURN @RESULT
END
GO