Warm tip: This article is reproduced from serverfault.com, please click
mariadb mysql sql

how to use mysql event scheduler to backup logs?

发布于 2020-12-02 05:42:43

I am storing my sql operation logs in a table sync_logger, and I want to save these logs to regular file periodically. In order to do so, I tried to create a event scheduler. but I always get following error at select statement.

MariaDB [sync]> DELIMITER !!
MariaDB [sync]> CREATE EVENT IF NOT EXISTS write_to_log_event
    -> ON SCHEDULE
    -> EVERY 1 DAY
    -> DO
    -> BEGIN
    -> DECLARE log_file VARCHAR(255);
    -> SET log_file = CONCAT('/var/log/sync_db_log_' ,DATE_FORMAT(NOW(), '%Y%m%d%H%i%S'));
    -> SELECT * INTO OUTFILE log_file from sync_logger;
    -> DELETE FROM sync_logger;
    -> END;
    -> !!
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'log_file from sync_logger;
DELETE FROM sync_logger;
END' at line 8
MariaDB [sync]> delimiter ;

I can't figure out what the problem is. Can anyone help?

Questioner
suihe dolood
Viewed
0
分享
Akina 2020-12-02 14:09:16

The name of output file is a literal, not a parameter, and it won't be replaced with variable value. Also the filename must be quoted.

Use prepared statement:

CREATE EVENT IF NOT EXISTS write_to_log_event
ON SCHEDULE
EVERY 1 DAY
DO
BEGIN
SET @write_to_log_event_sql := CONCAT('SELECT * INTO OUTFILE ''/var/log/sync_db_log_' ,
                                      DATE_FORMAT(NOW(), '%Y%m%d%H%i%S'), 
                                      ''' FROM sync_logger');
-- SELECT @write_to_log_event_sql; -- for debugging purposes
PREPARE stmt FROM @write_to_log_event_sql;
EXECUTE stmt;
DROP PREPARE stmt;
TRUNCATE sync_logger;
END

PS. TRUNCATE is faster than DELETE.

suihe dolood 2020-12-04 02:24:53

It works. Thank you very much.

热门github

1
Implementation of paper - YOLOv9: Learning What You Want to Learn Using Programmable Gradient Information
2
A Windows and Office activator using HWID / Ohook / KMS38 / Online KMS activation methods, with a focus on open-source code and fewer antivirus detections.
3
Get up and running with Llama 2, Mistral, Gemma, and other large language models.
4
该项目可以让你通过订阅的方式使用Cloudflare WARP+，自动获取流量。This project enables you to use Cloudflare WARP+ through subscription, automatically acquiring traffic.
5
Multi functional app to find duplicates, empty folders, similar images etc.
6
Xray panel supporting multi-protocol multi-user expire day & traffic & ip limit (Vmess & Vless & Trojan & ShadowSocks & Wireguard)
7
The Free Software Media System
8
lightweight, standalone C++ inference engine for Google's Gemma models.
9
📚 Freely available programming books
10
A collective list of free APIs
11
1️⃣🐝🏎️ The One Billion Row Challenge -- A fun exploration of how quickly 1B rows from a text file can be aggregated with Java
12
🎓 Path to a free self-taught education in Computer Science!
13
Curso para aprender el lenguaje de programación Python desde cero y para principiantes. 75 clases, 37 horas en vídeo, código, proyectos y grupo de chat. Fundamentos, frontend, backend, testing, IA...
14
This repository contains System Design resources which are useful while preparing for interviews and learning Distributed Systems
15
Mamba is a new state space model architecture showing promising performance on information-dense data such as language modeling, where previous subquadratic models fall short of Transformers. It is based on the line of progress on structured state space models, with an efficient hardware-aware design and implementation in the spirit of FlashAttention.