Posted about 12 years ago by Lexy. friendlyorm.com

Store schema-less data in MySQL...

Posted about 12 years ago by Lexy. bret.appspot.com

...some deliberation, we decided to implement a "schema-less" storage system on top of MySQL rather than use a completely new storage system. This post attempts to describe the high...

Posted almost 10 years ago by Andreas Robecke.

In MySQL comparing zero to a string 0 = "any string" is always true! So when you want to compare a string with a value of an integer column, you have...

Posted almost 7 years ago by Arne Hartherz.

...lives in another table, you need to JOIN both tables during the UPDATE. In MySQL you can do it like this: UPDATE employees LEFT JOIN departments ON employees.department_id = departments.id...

Posted over 7 years ago by Andreas Robecke. dev.mysql.com

Directly from the MySql docs: There are three likely causes for this error message. Usually it indicates network connectivity trouble and you should check the condition of your network if...

Posted almost 8 years ago by Henning Koch. codeka.com.au

For reasons that completely escape me, MySQL 5.x limits UTF-8 strings to U+FFFF and smaller...

Posted over 10 years ago by Henning Koch.

...database server your application runs on. Like MAX or COUNT, GROUP_CONCAT is a MySQL aggregation function you can use whenever your query contains a GROUP BY. You can use...

Posted about 9 years ago by Henning Koch.

When searching for text in a MySQL table, you have two choices: The LIKE operator FULLTEXT indexes (which currently only work on MyISAM tables, but will one day work on...

...pain and you will eventually need to deal with it, probably using a non-Mysql solution...

Posted over 9 years ago by Martin Straub.

When you work in the MySQL console and you want to see which database is used, type: SELECT database(); The result you see is the database you would activate with...

Posted over 9 years ago by Henning Koch.

For string columns, MySQL indexes the left side of a string. That means an index can speed a like query that has a wildcard on the right side:

Posted over 9 years ago by Henning Koch. dev.mysql.com

The next version of MySQL will include a built-in memcached daemon. This daemon can quickly get and set key/value pairs from and to InnoDB tables while completely bypassing the...

Posted over 9 years ago by Henning Koch.

Unless you changed the default, this will be 16 MB: mysql> SHOW VARIABLES WHERE Variable_name="max_allowed_packet"; +--------------------+----------+ | Variable_name | Value | +--------------------+----------+ | max_allowed_packet...

Posted over 9 years ago by Henning Koch.

...month / 3.0).ceil #=> 1 Yes, you do actually divide by 3.0, not 4.0. MySQL has SELECT QUARTER...

Posted over 10 years ago by Henning Koch.

In order to open a MySQL shell without the need to enter user and password, you can say the following in any Rails 2 project: script/dbconsole -p

Posted almost 11 years ago by Henning Koch.

MySQL's MIN and MAX functions are for aggregations only. This will not work and produce an error: SELECT id, MIN(birthday, '1978-01-01') FROM users;

Posted about 11 years ago by Thomas Eisenbarth.

If you need to export data from MySQL to a CSV, you can profit from really fast built-in methods. This query writes the data to /tmp/geodb_coodinates.csv. And it's...

Posted about 11 years ago by Henning Koch.

Use this MySQL command to show further info about a table: SHOW CREATE TABLE tags; This will output a table schema like this: CREATE TABLE `tags` ( `id` int(11) NOT...

Posted over 11 years ago by Henning Koch.

...be useful to have a Ruby expression like condition ? positive_case : negative_case in MySQL queries: UPDATE users SET monthly_debit = IF(subscriber...

This website uses short-lived cookies to improve usability.
Accept or learn more