事务必须有四个属性：原子性、一致性、隔离性、持久性，这四个属性的首字母可以缩写为ACID。

以下代码定义了一个事务，插入新订单数据：

-- Start a new transactionBEGIN TRAN;  -- Declare a variable  DECLARE @neworderid AS INT;  -- Insert a new order into the Sales.Orders table  INSERT INTO Sales.Orders      (custid, empid, orderdate, requireddate, shippeddate,        shipperid, freight, shipname, shipaddress, shipcity,       shippostalcode, shipcountry)    VALUES      (85, 5, '20090212', '20090301', '20090216',       3, 32.38, N'Ship to 85-B', N'6789 rue de l''Abbaye', N'Reims',       N'10345', N'France');  -- Save the new order ID in a variable  SET @neworderid = SCOPE_IDENTITY();  -- Return the new order ID  SELECT @neworderid AS neworderid;  -- Insert order lines for new order into Sales.OrderDetails  INSERT INTO Sales.OrderDetails      (orderid, productid, unitprice, qty, discount)    VALUES(@neworderid, 11, 14.00, 12, 0.000);  INSERT INTO Sales.OrderDetails      (orderid, productid, unitprice, qty, discount)    VALUES(@neworderid, 42, 9.80, 10, 0.000);  INSERT INTO Sales.OrderDetails      (orderid, productid, unitprice, qty, discount)    VALUES(@neworderid, 72, 34.80, 5, 0.000);-- Commit the transactionCOMMIT TRAN;