mysql 死循环

-- 错误的查询示例，可能导致死循环
SELECT * FROM table_name WHERE id IN (SELECT id FROM table_name);

-- 正确的查询示例，使用JOIN替代IN子查询
SELECT t1.* 
FROM table_name t1 
JOIN (SELECT DISTINCT id FROM table_name) t2 ON t1.id = t2.id;

-- 错误的事务示例，可能导致死循环
START TRANSACTION;
DO SOMETHING;
IF NOT CONDITION_MET THEN
    ROLLBACK;
    START TRANSACTION; -- 这里会导致死循环
END IF;
COMMIT;

-- 正确的事务示例，增加重试次数限制
SET @retry_count = 0;
START TRANSACTION;
DO SOMETHING;
WHILE NOT CONDITION_MET AND @retry_count < MAX_RETRY DO
    ROLLBACK;
    SET @retry_count = @retry_count + 1;
    START TRANSACTION;
    DO SOMETHING;
END WHILE;
COMMIT;