What is a better way to write this SQL Stored Procedure?
I am updating a Trades Transactions Log using a SQL Stored Procedure, and I am updating Current Order Table at the same time with the same sproc.
Because I had a serious problem where the Log table did not update and the Current Order table did... I added a (3rd) routine to the bottom which checks to see if the Log Table was updated referencing an ID (ClientID), then entering an error if not present to error table.
I am asking... how badly written is this sproc ?? Help or advice appreciated.
ALTER PROCEDURE dbo.sprocVT4_addTradeLong
@seqno varchar(35) = NULL,
@exctyp varchar(35) = NULL,
@ordstat varchar(35) = NULL,
@clid varchar(35) = NULL,
@exid varchar(35) = NULL,
@type varchar(35) = NULL,
@side varchar(35) = NULL,
@exch varchar(35) = NULL,
@sym varchar(35) = NULL,
@lstqty varchar(35) = NULL,
@lstpri varchar(35) = NULL,
@text varchar(35) = NULL,
@cumqty varchar(35) = NULL,
@lftqty varchar(35) = NULL,
@now varchar(35) = NULL
AS
BEGIN
-- NO EXISTS ------------
Declare @RC int
SELECT [Symbol] FROM TradesLongForex T WHERE T.ExecId = @exid
SELECT @RC = @@ROWCOUNT
IF @RC <= 0
INSERT INTO TradesLongForex ([SeqNo], [ExecType], [Status], [ClientId], [ExecId], [Type], [Side], [Exchange], [Symbol], [LastQty], [LastPrice], [Text开发者_JAVA技巧], [CummQty], [LeftQty], [Date])
VALUES (@seqno, @exctyp, @ordstat, @clid, @exid, @type, @side, @exch, @sym, @lstqty, @lstpri, @text, @cumqty, @lftqty, @now)
UPDATE OrdersIdHoldForex SET [OrdExcType] = @exctyp, [OrdStatus] = @ordstat, [OrdType] = @type, [OrdSide] = @side, [OrdPrice] = @lstpri, [OrdQty] = @cumqty, [OrdRemain] = @lftqty
WHERE [Ticker] = @sym
DECLARE @RC2 int
SELECT @RC2 = @@ROWCOUNT
SELECT [ClientId] FROM TradesLongForex WHERE [ClientId] = @clid
if @RC2 <=0
INSERT INTO ERRLOG ([Date], [Message])
VALUES (GETDATE(), 'ERROR INSERTING TRADESLONGFOREX CLID = ' + CONVERT(varchar(10),@CLID))
END
Phil makes a good point about transactions. This concept is called "Atomicity" and basically means each transaction/process is atomic and self contained.
The general syntax for transactions in SQL server would be something like:
BEGIN TRY
BEGIN TRANSACTION
...
your code here
...
COMMIT TRANSACTION
END TRY
BEGIN CATCH
IF @@TRANCOUNT > 1 ROLLBACK
... error reporting code ...
END CATCH
The gist of this is, use TRY/CATCH
blocks to trap the errors, and only commit the transaction if you get through the whole TRY
block without issues. Any errors send you to the CATCH
block, which rolls back the open transaction.
Here's a primer on error handling.
I'm not 100% sure what you are asking, but it seems that you need to read up a bit on database transactions. Essentially you can wrap the set of queries in a transaction, and it will ensure that either all of the operations are completed, or none of them are. So if an error occurs, the entire operation will be rolled back.
http://en.wikipedia.org/wiki/Database_transaction
精彩评论