相关疑难解决方法(0)

我有一个MySQL存储过程,我从表中找到最大值.

如果没有值,我想将变量设置为昨天的日期.

DECLARE current_procedure_name CHAR(60) DEFAULT 'accounts_general';
DECLARE last_run_time datetime DEFAULT NULL;
DECLARE current_run_time datetime DEFAULT NOW();

-- Define the last run time
SET last_run_time := (SELECT MAX(runtime) 
FROM dynamo.runtimes WHERE procedure_name = @current_procedure_name);

-- if there is no last run time found then use yesterday as starting point
IF(@last_run_time IS NULL) THEN
    SET last_run_time := DATE_SUB( NOW(), INTERVAL 1 DAY);
END IF;

SELECT @last_run_time;

问题是@last_run_time始终为NULL.

由于某种原因,以下代码未被执行

IF(last_run_time IS NULL) THEN
    SET last_run_time := DATE_SUB( NOW(), INTERVAL 1 …