Multiple values in a column

Question

Hi

I need some advice regarding multiple records. I have a table with fields username,*message* and message_to. the scenario could be of sending same message to multiple users in a go. What do you suggest? will it be efficient to save all recipients in a single column with comma separated values or I add multiple entries ?

Thanks

/A

Answer 1

No, no, no, no, no.

This would be a capital violation of the relational database model.

Create three tables: Users, Messages, and MessagesSentToUsers.

In the Users table, store a user_id value, and the user's name.

In the Messages table, store a message_id value and the message text.

In the MessagesSentToUsers table create on record for each time a message is sent. This record should contain only the user_id for the user who got the message, and a message_id pointing to the message text they received.

In general, the id columns in each table will be of type integer. The most common case is to have the DBMS assign a value to each row (so you don't have to manage the numbers).