我对Laravel,PHP和MySql的了解有限。我正在尝试使用外键设置一个包含3个连接表的数据库。我之前在WorkBench MySql中手动完成了这个操作,但我无法在Laravel中完成。这是我的错误和我的代码。
SQL STATE[42000]: Syntax error or access violation: 1072 Key column 'cat_id
' doesn't exist in table (SQL: alter table `users` add index `users_cat_id
_usr_id_index`(`cat_id`, `usr_id`))
表格1
public function up()
{
Schema::create('users', function (Blueprint $table) {
$table->increments('usr_id')->autoIncrement();
$table->string('usr_email',45)->unique();
$table->string('usr_password',256);
$table->rememberToken();
$table->string('usr_name',45);
$table->string('usr_surname',45);
$table->string('usr_title',45);
$table->string('usr_psc',5);
$table->string('usr_region',128);
$table->string('usr_adress',128);
$table->string('usr_tel',10);
$table->string('usr_tel_int',13);
$table->binary('usr_image');
$table->tinyInteger('usr_type');
$table->index(['cat_id','usr_id'])->nullable();
$table->index(['tem_id','usr_id'])->nullable();
});
}
表2
public function up()
{
Schema::create('category', function (Blueprint $table) {
$table->primary('cat_id');
$table->string('cat_name',45);
});
Schema::table('category', function(Blueprint $table) {
$table->foreign('cat_id')->references('cat_id')->on('users');
});
}
表3
public function up()
{
Schema::create('team', function (Blueprint $table) {
$table->increments('tem_id');
$table->unique('tem_sub_id');
$table->string('tem_name',45);
$table->string('tem_subteam_name',45);
});
Schema::table('team', function(Blueprint $table) {
$table->foreign('tem_id')->references('tem_id')->on('users');
});
}
发生错误是因为cat_id
表中不存在users
。除此之外,在编写Laravel迁移时需要记住一些要点:
FOREIGN_KEY_CHECKS
to 0,否则您只能引用现有表,这就是我在下面的示例中更改创建表的顺序的原因。因为Laravel Eloquent ORM严重依赖标准,我建议以下面的方式重写你的表格,跟随Laravel Eloquent conventions:
表类别
public function up()
{
Schema::create('categories', function (Blueprint $table) {
$table->increments('id');
$table->string('name',45);
// etc...
});
}
表团队
public function up()
{
Schema::create('teams', function (Blueprint $table) {
$table->increments('id');
$table->string('name',45);
// etc...
});
}
表用户
public function up()
{
Schema::create('users', function (Blueprint $table) {
$table->increments('id');
$table->integer('category_id')->unsigned()->nullable();;
$table->foreign('category_id')->references('id')->on('categories');
$table->integer('team_id')->unsigned()->nullable();
$table->foreign('team_id')->references('id')->on('teams');
$table->string('email',45)->unique();
// etc...
});
}