如何利用Transact-SQL执行事务

如何利用Transact-SQL执行事务

下列存储过程说明了如何在Transact-SQL过程内执行事务的支金转移操作。

CREATE PROCEDURE MoneyTransfer
@FromAccount char(20),
@ToAccount char(20),
@Amount money
AS
BEGIN TRANSACTION
-- PERFORM DEBIT OPERATION
UPDATE Accounts
SET Balance = Balance - @Amount
WHERE AccountNumber = @FromAccount
IF @@RowCount = 0
BEGIN
  RAISERROR('Invalid From Account Number', 11, 1)
  GOTO ABORT
END
DECLARE @Balance money
SELECT @Balance = Balance FROM ACCOUNTS
WHERE AccountNumber = @FromAccount
IF @BALANCE < 0
BEGIN
  RAISERROR('Insufficient funds', 11, 1)
  GOTO ABORT
END
-- PERFORM CREDIT OPERATION
UPDATE Accounts 
SET Balance = Balance + @Amount 
WHERE AccountNumber = @ToAccount
IF @@RowCount = 0
BEGIN
  RAISERROR('Invalid To Account Number', 11, 1)
  GOTO ABORT
END
COMMIT TRANSACTION
RETURN 0
ABORT:
  ROLLBACK TRANSACTION
GO

该存储过程使用BEGIN TRANSACTION， COMMIT TRANSACTION，和ROLLBACK TRANSACTION状态手工控制事务。