Question

I am pretty new to MySQL and databases but I’m trying to learn 🙂

I’ve set up a database with 2 tables right now. The first of them, user_info, contains a list of users for an online app, as well as their account information, such as; username, password, first and last names. It also has a column labeled “list_access” for another table.

The second table, word_lists, is a set of rows/records. Each column will contain a single word (other than the first column being the primary key/id column). The idea is that the app will check the user’s data in their account information, and see which word records they have access to, then pull the word lists into the app into an array.

Is this an effective way to set this up? What type of data should the column in the user_info table, in the list_access column be? I’m having a hard time figuring out how to have that list which ones would be accessible, and then have it verify which ones to pull from. Would that be something typically handled by the app, or by a php script?

I really appreciate any help as it has been a slow process piecing everything I’ve learned together so far.

Answer 1

If you have one column in the user_info table for list_access, think about what you’re going to store in it:

1. a single word_list ID
2. a list of word_list IDs, e.g. “1,2,3,4”.

Item #1 is bad because it goes against your requirements to check “which word records” to use.

Item #2 is bad because you’ll have to always be joining/splitting/merging that list together and you can never have referential integrity.

What you really want is a cross reference table that joins the user to the word list, like this:

 CREATE TABLE user_word_lists (
     user_id int unsigned not null,
     word_list_id int unsigned not null
 )

This table would have multiple rows for each user. Setup the foreign keys to the two source tables, and put in the indexes you’ll need (certainly user_id).

Hope that helps.