在sqlselect语句中使用case

根据您的具体需要进行修改

SELECT
   CASE WHEN Amount < 0 THEN ABS(Amount) ELSE NULL AS Debit,
   CASE WHEN Amount >= 0 THEN Amount ELSE NULL AS Credit
FROM
   SomeTable

SELECT Amount, CASE WHEN Amount < 0 THEN 'Debit' ELSE 'Credit' END AS Type
FROM SomeTable

如。

create function dbo.CreditOrDebit (@amount decimal(9,2), @type char(6))
returns decimal(9,2)
as
begin
declare @output decimal(9,2);
select @output =
    case @type
    when 'debit' then
        case 
            when @amount < 0.00 then ABS(@amount) 
            else 0
        end
    else
        case 
            when @amount >= 0.00 then ABS(@amount) 
            else 0
        end
    end;
    return @output;
end

select jv.AccountNo,jv.AccountNoTitle,(select JV_GroupsHead.GroupTitle
    from JV_GroupsHead where JV_GroupsHead.Id=jv.GroupId) as 'GroupName'
,dbo.CreditOrDebit(jv.Revenue,'debit') as debit
,dbo.CreditOrDebit(jv.Revenue,'credit') as credit