Find and Replace text in the entire table using a MySQL query

Usually I use manual find to replace text in a MySQL database using phpmyadmin. I'm tired of it now, how can I run a query to find and replace a text with new text in the entire table in phpmyadmin?

Example: find keyword domain.com, replace with www.domain.com.

For a single table update

 UPDATE `table_name`
 SET `field_name` = replace(same_field_name, 'unwanted_text', 'wanted_text')

From multiple tables-

If you want to edit from all tables, best way is to take the dump and then find/replace and upload it back.

The easiest way I have found is to dump the database to a text file, run a sed command to do the replace, and reload the database back into MySQL.

All commands below are bash on Linux.

Dump database to text file

mysqldump -u user -p databasename > ./db.sql

Run sed command to find/replace target string

sed -i 's/oldString/newString/g' ./db.sql

Reload the database into MySQL

mysql -u user -p databasename < ./db.sql

Easy peasy.