associationのまとめ
belongsTo
1つの関連をもつ。
- 例) Players.belongsTo(Teams)
Playersに外部キー
teamIdが自動追加される。
hasOne
1つの関連をもつ。
- 例) Players.hasOne(Profiles)
Profilesに外部キーplayerIdが自動追加される。include時、最初の１つのみ出力される。
hasMany
複数の関連をもつ。
- 例) Players.hasMany(Profiles)
Profilesに外部キーplayerIdが自動追加される。include時、複数件出力される。
belongsToMany
多対多の中間テーブルを持つ。
例1)Players.belongsToMany(Teams, { through: TeamPlayers })
中間テーブル'TeamPlayers'が作成され、そこに外部キーteamIdplayerIdが自動追加される例2)Teams.belongsToMany(Players, { through: TeamPlayers })
中間テーブル'TeamPlayers'が作成され、そこに外部キーplayerIdteamIdが自動追加される
belongToとhasOneの違い
挙動はほぼ同じ。指定の順が変わっただけ。
belongsTo のサンプル
// model(テーブル)を定義// 主キー`id`や`createdAt`、`updatedAt`は勝手に定義されるので記述不要constPlayers=sequelize.define('players',{name:Sequelize.STRING,});constTeams=sequelize.define('teams',{name:Sequelize.STRING,});Players.belongsTo(Teams,{foreignKey:'team_id'})// playersに外部キー'team_id'が作成される。foreignKeyを省略した場合、キャメルケースでid名'teamId'が自動生成される// modelを元にDBテーブルの作成({force:true}オプションは、テーブルdrop&create)awaitPlayers.sync({force:true});awaitTeams.sync({force:true});// レコードのcreateconstteam1=awaitTeams.create({name:'team1'});constplayer1=awaitPlayers.create({name:'player1',team_id:team1.id});// レコード取得constplayer=awaitPlayers.findById(player1.id,{include:Teams})console.log(player.get({plain:true}))出力結果
{ id: 1,
name: 'player1',
createdat: 2019-08-29t02:36:21.464z,
updatedat: 2019-08-29t02:36:21.464z,
team_id: 1,
team:
{ id: 1,
name: 'team1',
createdat: 2019-08-29t02:36:21.448z,
updatedat: 2019-08-29t02:36:21.448z } }
以下でも、teams : players = 1 : n で取得できそうだが、できない
constteam=awaitTeams.findById(team1.id,{include:Players})出力結果
failed: sequelizeeagerloadingerror: players is not associated to teams!
hasOne のサンプル
// model(テーブル)を定義constPlayers=sequelize.define('players',{name:Sequelize.STRING,});constProfiles=sequelize.define('profiles',{name:Sequelize.STRING,});Players.hasOne(Profiles,{foreignKey:'player_id'})// modelを元にDBテーブルの作成awaitPlayers.sync({force:true});awaitProfiles.sync({force:true});// レコードのcreateconstplayer1=awaitPlayers.create({name:'player1'});constprofile1=awaitProfiles.create({name:'profile1',player_id:player1.id});constprofile2=awaitProfiles.create({name:'profile2',player_id:player1.id});// レコードの取得constplayer=awaitPlayers.findById(player1.id,{include:Profiles})console.log(player.get({plain:true}))出力結果
{ id: 1,
name: 'player1',
createdAt: 2019-08-29T03:59:30.432Z,
updatedAt: 2019-08-29T03:59:30.432Z,
profile:
{ id: 1,
name: 'profile1',
createdAt: 2019-08-29T03:59:30.448Z,
updatedAt: 2019-08-29T03:59:30.448Z,
player_id: 1 } }
hasMany のサンプル
// model(テーブル)を定義constPlayers=sequelize.define('players',{name:Sequelize.STRING,});constProfiles=sequelize.define('profiles',{name:Sequelize.STRING,});Players.hasMany(Profiles,{foreignKey:'player_id'})// modelを元にDBテーブルの作成awaitPlayers.sync({force:true});awaitProfiles.sync({force:true});// レコードのcreateconstplayer1=awaitPlayers.create({name:'player1'});constprofile1=awaitProfiles.create({name:'profile1',player_id:player1.id});constprofile2=awaitProfiles.create({name:'profile2',player_id:player1.id});// レコードの取得constplayer=awaitPlayers.findById(player1.id,{include:Profiles})// hasOneだと最初の１件しか取得できないがhasManyだと全て取得できるconsole.log(player.get({plain:true}))出力結果
{ id: 1,
name: 'player1',
createdAt: 2019-08-29T04:13:05.396Z,
updatedAt: 2019-08-29T04:13:05.396Z,
profiles:
[ { id: 1,
name: 'profile1',
createdAt: 2019-08-29T04:13:05.412Z,
updatedAt: 2019-08-29T04:13:05.412Z,
player_id: 1 },
{ id: 2,
name: 'profile2',
createdAt: 2019-08-29T04:13:05.428Z,
updatedAt: 2019-08-29T04:13:05.428Z,
player_id: 1 } ] }
belongsToMany のサンプル
// model(テーブル)を定義// 主キー'id'や'createdAt'、'updatedAt'は勝手に定義されるので記述不要constPlayers=sequelize.define('players',{name:Sequelize.STRING,});constTeams=sequelize.define('teams',{name:Sequelize.STRING,});constTeamPlayers=sequelize.define('team_players',{name:Sequelize.STRING,});// 中間テーブル'TeamPlayers'を作成し、そこに'team_id'を追加するPlayers.belongsToMany(Teams,{through:TeamPlayers,foreignKey:'team_id'})// 中間テーブル'TeamPlayers'を作成し、そこに'team_id'を追加するTeams.belongsToMany(Players,{through:TeamPlayers,foreignKey:'player_id'})awaitTeamPlayers.sync({force:true});awaitPlayers.sync({force:true});awaitTeams.sync({force:true});// レコードのcreateconstteam1=awaitTeams.create({name:'team1'});constteam2=awaitTeams.create({name:'team2'});constplayer1=awaitPlayers.create({name:'player1'});player1.addTeam(team1,{status:'started'})player1.addTeam(team2,{status:'started'})constplayer2=awaitPlayers.create({name:'player2'});player2.addTeam(team1,{status:'started'})player2.addTeam(team2,{status:'started'})// レコード取得constplayer=awaitPlayers.findById(player1.id,{include:Teams})console.log(player.get({plain:true}))constteam=awaitTeams.findById(team1.id,{include:Players})console.log(team.get({plain:true}))出力結果
{ id: 1,
name: 'player1',
createdAt: 2019-08-29T05:56:11.200Z,
updatedAt: 2019-08-29T05:56:11.200Z,
teams:
[ { id: 1,
name: 'team1',
createdAt: 2019-08-29T05:56:11.168Z,
updatedAt: 2019-08-29T05:56:11.168Z,
team_players: [Object] },
{ id: 2,
name: 'team2',
createdAt: 2019-08-29T05:56:11.184Z,
updatedAt: 2019-08-29T05:56:11.184Z,
team_players: [Object] } ] }
{ id: 1,
name: 'team1',
createdAt: 2019-08-29T05:56:11.168Z,
updatedAt: 2019-08-29T05:56:11.168Z,
players:
[ { id: 1,
name: 'player1',
createdAt: 2019-08-29T05:56:11.200Z,
updatedAt: 2019-08-29T05:56:11.200Z,
team_players: [Object] },
{ id: 2,
name: 'player2',
createdAt: 2019-08-29T05:56:11.217Z,
updatedAt: 2019-08-29T05:56:11.217Z,
team_players: [Object] } ] }