sql - Need a database efficiency suggestion -

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i have following database table. trying figure out way can structure can have position each player column. because each user going have multiple players , there multiple users, cannot figure out best way model db table 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 thing can think of adding player_position ever player, 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 better, more efficient way this?

if want design efficient databases, i'd suggest first atleast knowledge normalization.

to learn basics of normalization, refer to:

clearly database not normalized , needs normalization.

issue 1: achieve 1st normalization form assigning primary key.

issue 2: database consists of transitive dependency(transitive dependency if consider id primary key. thereafter, player fields depend upon non key attribute. i.e. user_id).

  • fix creating different tables user , player.
  • also take @ concept of foreign key.

if fix these 2 issues you'll no longer need both id , user_id together. can drop 1 of them.

final database schema:

create table `user` (     `user_id`   int(11) not null primary key, /*make auto_increment if 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 auto_increment if 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 type of database you're using.


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