You have a cms and a big database with over 100 tables and 100.000 entries. And you need to replace all entries contain "example.com" with "www.example.com". How you do that? Editing all entries manually with phpmyadmin? It could takes weeks to complete. I have found a solution and want to share with you.
Steps:
1. Export your whole database in a text file : db.sql
2. Replace string using Linux sed command
3. Empty your db and import new sql file
Export your mysql database into a text file: db.sql
mysqldump -u root -p your_database_name > db.sql
Replate old string text with new one
sed 's/http:\/\/example.com\//http:\/\/www.example.com\//g' db.sql > db.sql.replaced
Empty DB with drop all tables with phpmyadmin. (Do not drop database self)
Import replaced new .sql to database
mysql -u root -p your_database_name < db.sql.replaced