Using case in a sql select statement

问题

Consider a table with a column amount,

Amount
-1235.235
1356.45
-133.25
4565.50
5023
-8791.25

I want to my result pane to be like this,

Debit   Credit
  0     -1235.235
1356.45  0 
  0     -133.25

Here is my stored procedure,

USE [HotelBI_CustomDB]
GO
  SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE [dbo].[SP_GetJVReport](
@p_FromDate datetime,
@p_ToDate datetime
)
AS
BEGIN
select jv.AccountNo,jv.AccountNoTitle,(select JV_GroupsHead.GroupTitle
    from JV_GroupsHead where JV_GroupsHead.Id=jv.GroupId) as 'GroupName'
,jv.Revenue --" This column i need to check and have to split it into two 
               column "credeit,debit""

from JVFunction1(@p_FromDate,@p_ToDate) as jv

END

How to write a select statement such that it uses a case like amount>=0 as credit and amount <0 as debit?

回答1:

Modify as needed for your exact needs

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

回答2:

Do you mean like this, a separate column to indicate the type of the amount?

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

回答3:

I'd probably create a User-Defined Function to make this a bit easier.

eg.

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

Then use it in your Select statement like this:

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

来源：https://stackoverflow.com/questions/3759167/using-case-in-a-sql-select-statement

标签

sql-server-2005

select

case