多表数据库设计

Question

I have a website where I display a list of sports players and their stats. Users can register and create a team of these players where I sum and analyze the team stats. I would like to give each user the ability to "cross out" a player from the list (yet not remove them from the database) and reinstate a player that has been crossed out back to the list if they need to. The players that are crossed out or not crossed out need to be saved in a database so when the user returns to the site their list is saved.

These are the tables I currently have:

Players Table (COLS: Name, Team, Position, Stats, etc.)
Users Table (COLS: User ID, Name, Email, etc.)
Teams Table (COlS: User ID, 1, 2, 3, etc.)

I'm pretty sure that there is a better way to store the info in the Teams Table where I have a column for user id and then 30 columns (numbered 1-30) where I store the player name and position he was selected for in the cell (in this format Player Name/Position). A team can consist up to 30 players.

I think I would need an "Available Table" that stores which players are crossed out by which users. I'm not sure what is the best way to go about this considering a user can cross out up to 600 players from the list.

Any suggestions would be greatly appreciated, I'm completely new to dealing with databases and I have seem to hit a wall.

Thanks!

Answer 1

You should probably remove the player data from the team table and set up a join table for the players and team data.

So you end up with

Teams Table (Cols: ID, User ID, Team Name)
Team_Players Table (Cols: Team_ID, Player_ID, Position, Active)

You can then get which players are in which team by running a query on Team_Players and check if they are active or not.

I didn't add an ID field because the join of Team_ID and Player_ID would be unique and could be used as the key for this table.

Answer 2

Read this tutorial . It is very helpful:

http://www.tomjewett.com/dbdesign/dbdesign.php?page=association.php

The design of your database depends on whether a given player can belong to more than one team in the database. If it can, that is a has and belongs to many relationship and you would need a linking table, perhaps called Players_Teams (always list tables in alpha order). This table could also contain the crossedOff column you were talking about.

Using an ORM (Object Relational Mapper) like ActiveRecord or Doctrine can greatly reduce the amount of code you need to write to make the management of these relationships somewhat "automatic" in your code.