SQL 函数返回字符串中的最大值最小值(XML新解法)

SQL 函数返回字符串中的最大值最小值(XML新解法)

集合中的最大值，最小值在收集和集合中的值的数目。

/*

 例：

运行下面的函数

select* from dbo.GetMaxandMinValue('2,22,5,1,88,2000,7897,800',',')

 得到这样的结果

minValue  maxValue  CountOfNumberSupplied

-------------------------------------------------------------------

1.007897.00 8

*/

if object_id('GetMaxandMinValue','F') is not null drop function GetMaxandMinValue

go

create functionGetMaxandMinValue(@valuescollection varchar(max),@separator char(1))

returns @table table(minvalue numeric(20,2),maxvalue numeric(20,2),countofnumbersupplied int)

as

begin

    declare @x xml

    declare @minnumber varchar(50)

    declare @maxnumber varchar(50)

    declare @numbercount varchar(20)

    select @x='<number>' + replace(@valuescollection,@separator,'</number><number>')+ '</number>'

    select @minnumber= convert(varchar(50),@x.query('fn:min(number)') )

    select @maxnumber= convert(varchar(50),@x.query('fn:max(number)'))

    select @numbercount= convert(varchar(50),@x.query('fn:count(number)'))

    insert into @table select cast(@minnumber as float),cast(@maxnumber as float),cast(@numbercount as int)

    return;

end

go

select * from dbo.GetMaxandMinValue('2,22,5,1,88,2000,7897,800',',')