How to enable MySQL Query Log? - mysql

Question

How do I enable the MySQL function that logs each SQL query statement received from clients and the time that query statement has submitted?
Can I do that in phpmyadmin or NaviCat?
How do I analyse the log?

Answer 1

First, Remember that this logfile can grow very large on a busy server.
For mysql < 5.1.29:
To enable the query log, put this in /etc/my.cnf in the [mysqld] section
log = /path/to/query.log #works for mysql < 5.1.29
Also, to enable it from MySQL console
SET general_log = 1;
See http://dev.mysql.com/doc/refman/5.1/en/query-log.html
For mysql 5.1.29+
With mysql 5.1.29+ , the log option is deprecated. To specify the logfile and enable logging, use this in my.cnf in the [mysqld] section:
general_log_file = /path/to/query.log
general_log = 1
Alternately, to turn on logging from MySQL console (must also specify log file location somehow, or find the default location):
SET global general_log = 1;
Also note that there are additional options to log only slow queries, or those which do not use indexes.

Answer 2

Take a look on this answer to another related question. It shows how to enable, disable and to see the logs on live servers without restarting.
Log all queries in mysql
Here is a summary:
If you don't want or cannot restart the MySQL server you can proceed like this on your running server:
Create your log tables (see answer)
Enable Query logging on the database
(Note that the string 'table' should be put literally and not substituted by any table name. Thanks Nicholas Pickering)
SET global general_log = 1;
SET global log_output = 'table';
View the log
select * from mysql.general_log;
Disable Query logging on the database
SET global general_log = 0;
Clear query logs without disabling
TRUNCATE mysql.general_log

Answer 3

This was already in a comment, but deserves its own answer:
Without editing the config files: in mysql, as root, do
SET global general_log_file='/tmp/mysql.log';
SET global log_output = 'file';
SET global general_log = on;
Don't forget to turn it off afterwards:
SET global general_log = off;

Answer 4

I use this method for logging when I want to quickly optimize different page loads.
It's a little tip...
Logging to a TABLE
SET global general_log = 1;
SET global log_output = 'table';
You can then select from my mysql.general_log table to retrieve recent queries.
I can then do something similar to tail -f on the mysql.log, but with more refinements...
select * from mysql.general_log
where event_time > (now() - INTERVAL 8 SECOND) and thread_id not in(9 , 628)
and argument <> "SELECT 1" and argument <> ""
and argument <> "SET NAMES 'UTF8'" and argument <> "SHOW STATUS"
and command_type = "Query" and argument <> "SET PROFILING=1"
This makes it easy to see my queries that I can try and cut back. I use 8 seconds interval to only fetch queries executed within the last 8 seconds.

Answer 5

You can disable or enable the general query log (which logs all queries) with
SET GLOBAL general_log = 1 # (or 0 to disable)

Answer 6

// To see global variable is enabled or not and location of query log
SHOW VARIABLES like 'general%';
// Set query log on
SET GLOBAL general_log = ON;

Answer 7

I also wanted to enable the MySQL log file to see the queries and I have resolved this with the below instructions
Go to /etc/mysql/mysql.conf.d
open the mysqld.cnf
and enable the below lines
general_log_file = /var/log/mysql/mysql.log
general_log = 1
restart the MySQL with this command /etc/init.d/mysql restart
go to /var/log/mysql/ and check the logs

Answer 8

On Windows you can simply go to
C:\wamp\bin\mysql\mysql5.1.53\my.ini
Insert this line in my.ini
general_log_file = c:/wamp/logs/mysql_query_log.log
The my.ini file finally looks like this
...
...
...
socket = /tmp/mysql.sock
skip-locking
key_buffer = 16M
max_allowed_packet = 1M
table_cache = 64
sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 8M
basedir=c:/wamp/bin/mysql/mysql5.1.53
log = c:/wamp/logs/mysql_query_log.log #dump query logs in this file
log-error=c:/wamp/logs/mysql.log
datadir=c:/wamp/bin/mysql/mysql5.1.53/data
...
...
...
...

Answer 9

There is bug in MySQL 5.6 version.
Even mysqld show as :
Default options are read from the following files in the given order:
C:\Windows\my.ini C:\Windows\my.cnf C:\my.ini C:\my.cnf c:\Program Files (x86)\MySQL\MySQL Server 5.6\my.ini c:\Program Files (x86)\MySQL\MySQL Server 5.6\my.cnf
Realy settings are reading in following order :
Default options are read from the following files in the given order:
C:\ProgramData\MySQL\MySQL Server 5.6\my.ini C:\Windows\my.ini C:\Windows\my.cnf C:\my.ini C:\my.cnf c:\Program Files (x86)\MySQL\MySQL Server 5.6\my.ini c:\Program Files (x86)\MySQL\MySQL Server 5.6\my.cnf
Check file: "C:\ProgramData\MySQL\MySQL Server 5.6\my.ini"
Hope it help somebody.

Answer 10

for mysql>=5.5 only for slow queries (1 second and more)
my.cfg
[mysqld]
slow-query-log = 1
slow-query-log-file = /var/log/mysql/mysql-slow.log
long_query_time = 1
log-queries-not-using-indexes

Answer 11

To enable the query log in MAC Machine:
Open the following file:
vi /private/etc/my.cnf
Set the query log url under 'mysqld' section as follows:
[mysqld]
general_log_file=/Users/kumanan/Documents/mysql_query.log
Few machine’s are not logging query properly, So that case you can enable it from MySQL console
mysql> SET global general_log = 1;

Answer 12

Not exactly an answer to the question because the question already has great answers. This is a side info. Enabling general_log really put a dent on MySQL performance. I left general_log =1 accidentally on a production server and spent hours finding out why performance was not comparable to a similar setup on other servers. Then I found this which explains the impact of enabling general log. http://www.fromdual.com/general_query_log_vs_mysql_performance.
Gist of the story, don't put general_log=1 in the .cnf file. Instead use set global general_log =1 for a brief duration just to log enough to find out what you are trying to find out and then turn it off.

Answer 13

In phpMyAdmin 4.0, you go to Status > Monitor. In there you can enable the slow query log and general log, see a live monitor, select a portion of the graph, see the related queries and analyse them.

Answer 14

I had to drop and recreate the general log at one point. During the recreation, character sets got messed up and I ended up having this error in the logs:
[ERROR] Incorrect definition of table mysql.general_log: expected the type of column 'user_host' at position 1 to have character set 'utf8' but found character set 'latin1'
So if the standard answer of "check to make sure logging is on" doesn't work for you, check to make sure your fields have the right character set.

Answer 15

My OS Win10, MySQL server version - 5.7
The path to my.ini
C:\ProgramData\MySQL\MySQL Server 5.7\my.ini
Just add into my.ini file
general_log_file = C:/ProgramData/MySQL/MySQL Server 5.7/mysql.log
general_log = 1

Answer 16

You may come across a set of Hexadecimal values, like this (argument column):
mysql> select * from mysql.general_log LIMIT 1\G
*************************** 1. row ***************************
event_time: 2023-01-27 13:37:20.950778
user_host: root[root] # localhost []
thread_id: 1434
server_id: 1
command_type: Query
argument: 0x73656C656374202A2066726F6D207573657273
1 row in set (0.00 sec)
so to make it readable, just use:
select a.*, convert(a.argument using utf8) from mysql.general_log a;
And the return is something like this:
mysql> select a.*, convert(a.argument using utf8) from mysql.general_log a LIMIT 1\G
*************************** 1. row ***************************
event_time: 2023-01-27 13:37:20.950778
user_host: root[root] # localhost []
thread_id: 1434
server_id: 1
command_type: Query
argument: 0x73656C656374202A2066726F6D207573657273
convert(a.argument using utf8): select * from users
1 row in set, 1 warning (0.00 sec)
Ps: I used LIMIT 1 on examples, because my log table is too big.