问题
Can not find a command that displays the current configuration of mysql from within the database.
I know I could look at /etc/mysql/my.cnf but that is not what I need.
回答1:
What you are looking for is this:
SHOW VARIABLES;
You can modify it further like any query:
SHOW VARIABLES LIKE '%max%';
回答2:
Use SHOW VARIABLES
:
show variables like 'version';
回答3:
As an alternative you can also query the information_schema
database and retrieve the data from the global_variables
(and global_status
of course too). This approach provides the same information, but gives you the opportunity to do more with the results, as it is a plain old query.
For example you can convert units to become more readable. The following query provides the current global setting for the innodb_log_buffer_size
in bytes and megabytes:
SELECT
variable_name,
variable_value AS innodb_log_buffer_size_bytes,
ROUND(variable_value / (1024*1024)) AS innodb_log_buffer_size_mb
FROM information_schema.global_variables
WHERE variable_name LIKE 'innodb_log_buffer_size';
As a result you get:
+------------------------+------------------------------+---------------------------+
| variable_name | innodb_log_buffer_size_bytes | innodb_log_buffer_size_mb |
+------------------------+------------------------------+---------------------------+
| INNODB_LOG_BUFFER_SIZE | 268435456 | 256 |
+------------------------+------------------------------+---------------------------+
1 row in set (0,00 sec)
来源:https://stackoverflow.com/questions/1493722/mysql-command-for-showing-current-configuration-variables