[英]Add foreign key constraints in Laravel migration
我知道很多人都問過同樣的問題很多次,但似乎我無法使相同的解決方案對我有用。
我無法為以下給出了up()
的相關表設置外鍵:
//Migrate 1 Starts
public function up()
{
Schema::create("UserTable", function($table){
$table->tinyInteger("ApplicationID");
$table->bigInteger("UserID");
$table->string("UserName")->unique();
$table->timestamps();
});
}
//Migrate 1 Ends
//Migrate 2 Starts
public function up()
{
Schema::create("Membership", function($table){
$table->tinyInteger("ApplicationID");
$table->bigInteger("UserID");
$table->string("Password");
}
}
//Migrate 2 Ends
//Migrate 3 Starts: This has the latest timestamp, so it runs after all tables are created
public function up()
{
Schema::table('UserTable', function($table) {
$table->primary("UserID");
$table->foreign("UserID")->references("UserID")->on("Membership");
});
Schema::table('Membership', function($table) {
$table->primary("UserID");
$table->foreign("UserID")->references("UserID")->on("UserTable");
});
}
//Migrate 3 Ends
我得到的錯誤是SQLSTATE[HY000]: General rror: 1215 Cannot add foreign key constraint (SQL: alter table 'Membership' add constraint membership_userid_foreign foreign key ('UserID') references 'UserTable' ('UserID'))
錯誤SQLSTATE[HY000]: General rror: 1215 Cannot add foreign key constraint (SQL: alter table 'Membership' add constraint membership_userid_foreign foreign key ('UserID') references 'UserTable' ('UserID'))
問題是我在設置外鍵時正在設置主鍵。 這引起了問題。
因此,必須在創建表時完成主列的設置,而在創建所有相關表后必須添加外鍵。
我認為最好在創建完所有表之后創建一個create_associations
遷移文件,以便此遷移具有最新的時間戳,並且在執行該文件時,所有表都已存在於數據庫中。
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