Use MySQL events to regularly perform post seven world line tasks

　　 Recently I did a recruitment project , There is a need for regular offline in the project . Before doing it, I've been thinking about using window service , Still use scheduling , In the end, I chose to use mysql Timing events , Because it's so simple and convenient .

Ideas ： First create a stored procedure , Update the corresponding position status through cursor traversal , Let's create a scheduled event after , Don't talk too much nonsense, just go to the code

First create a stored procedure ：

CREATE DEFINER = CURRENT_USER PROCEDURE `TimedDownLine`()
BEGIN
--  Declare variables （ For inserting data ）
DECLARE PostID INT;# Position ID
DECLARE DifferDay INT;# return int 
DECLARE done INT DEFAULT 0;# The basis for judging whether there is information 0 Indicates that there is data 

DECLARE Integral_cursor cursor for SELECT id,TIMESTAMPDIFF(DAY, ReleaseEnd, now()) AS intervalday FROM postrelease WHERE PostType=1;# Query all online position information （1 Indicates online position ,2 Indicates the offline position ）

 DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;# No data is returned and the status is changed to 1

--  Open cursor 
OPEN Integral_cursor;
# Start the cycle 
WHILE done=0 DO

#REPEAT
   # Cursor assignment ( The cursor will only execute downward )
     FETCH Integral_cursor INTO PostID,DifferDay;
     IF(done=0&&DifferDay>7)
     THEN UPDATE postrelease SET PostType=2 where ID=PostID;
   end IF;
# The loop ends 
#UNTIL done=1 END REPEAT;
END WHILE;
SET done=1;# Change state , Indicates the end of the cycle 
--  Close cursor 
END

Create database events ：

# Check whether the database event is enabled 
SHOW VARIABLES LIKE 'event_scheduler'
show variables like '%event%';
# Set the current event on 
SET GLOBAL event_scheduler = 1; 
# View scheduled tasks 
select * from  mysql.event;
SELECT * FROM information_schema.events; 
# It starts every morning 
select DATE_ADD(DATE_ADD(CURDATE(), INTERVAL 1 DAY), INTERVAL 13 HOUR) 
# Turn off scheduled tasks 
DROP event temp_event;


# It starts every morning （ Create timed events ）
CREATE EVENT IF NOT EXISTS TimeDownlines_event   
    ON SCHEDULE EVERY 1 DAY STARTS DATE_ADD(DATE_ADD(CURDATE(), INTERVAL 1 DAY), INTERVAL 0 HOUR)   
    ON COMPLETION PRESERVE ENABLE # Start the scheduled task on time  
    DO CALL TimedDownLine();

　　 In this way, it is possible to deal with some businesses rather than complex scheduled tasks , And the development is fast , Next time I have time, I will window The scheduled task of the service is written .