Need a database efficiency suggestion - sql

Question

I have the following database table. I am trying to figure out a way that I can structure this so that I can have a position for each player column. Because each user is going to have multiple players and there will be multiple users, I cannot figure out the best way to model my db table for efficiency.
CREATE TABLE `user_players` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`user_id` int(11) NOT NULL,
`firstname` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`lastname` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`username` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`email` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player1` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player2` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player3` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player4` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player5` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player6` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
The only thing that I can think of is adding a player_position for ever player, so that it would look like this...
`player1` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player_position1` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player2` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player_position2` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
Is there a better, more efficient way to do this?

Answer 1

You need separate tables for users and players. The player table will have a foreign key for the user that owns it.

Answer 2

If you want to design efficient databases, then I'd suggest you to first get atleast some knowledge about Normalization.
To learn basics of Normalization, refer to:
What is Normalisation (or Normalization)?
http://www.studytonight.com/dbms/database-normalization.php
https://www.youtube.com/watch?v=tCabZRVXv2I
Clearly your database is not Normalized and needs Normalization.
Issue 1:
Achieve 1st Normalization form by assigning a Primary Key.
Issue 2:
Your database consists of Transitive Dependency(Transitive dependency if you consider id as a primary key. Thereafter, player fields will depend upon non key attribute. i.e. user_id).
Fix it by creating different tables for user and player.
Also take a look at the concept of Foreign Key.
If you fix these two issues then you'll no longer need both id and user_id together. You can drop one of them.
Final Database Schema:
CREATE TABLE `user` (
`user_id` int(11) NOT NULL PRIMARY KEY, /*Make it AUTO_INCREMENT if you wish to*/
`firstname` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`lastname` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`username` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`email` varchar(100) COLLATE utf8_unicode_ci NOT NULL
)
CREATE TABLE `player` (
`player_id` int(11) NOT NULL PRIMARY KEY, /*Make it AUTO_INCREMENT if you wish to*/
`player1` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player2` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player3` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player4` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player5` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
`player6` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
FOREIGN KEY (user_id) REFERENCES user(user_id)
)
P.S.: Syntax may vary depending upon the type of database that you're using.