MYSQL SELECT into record empty issue

SELECT Id into @Id from giftcode WHERE Status = 1 and Giftid = #GiftId # ORDER by Id ASC LIMIT 1;
UPDATE giftcode SET usedtime = Now (), Status = 2,accountid = #AccountId # WHERE Id = @Id;
SELECT * from Giftcode WHERE Id = @Id;

Title, this 3 sentence SQL, there is no problem in server, if in MySQL, because the first sentence does not find records, affecting the number of rows is 0, does not perform into operations

The @Id variable that maintains the results from the previous session. (@ is a session variable), causing a program problem

Workaround:

In the first sentence: SET @Id = 0;

Can be solved, if there is a better solution, please post!

Environment: ASP. NET Framework 3.5/ibatis.net/mysql

MYSQL SELECT into record empty issue