Got a request from the boss today to extract all users plus their contact numbers from the Paging server

Server is a Red Hat Enterprise Linux AS release 4, running LAMP.

The data needed are located in several tables, so we need to query all relevant tables in the databse:

mysql> SELECT users.username, users.emailaddress, user_services.current_service FROM users, user_services WHERE users.username=user_services.username

The statement above queries two tables - users and user_services, as show from the expressin ‘FROM users, user_services’. The record in users table that information is required are in the username and emailaddress record. On user_services, it’s current_services. The WHERE sets the limit condition.

To send that output to a file, we use the INTO OUTFILE ‘</path/to/file>’.

So, that’s

mysql> SELECT users.username, users.emailaddress, user_services.current_service FROM users, user_services WHERE users.username=user_services.username INTO OUTFILE ‘/tmp/tempfile.txt’