我在一个新的Laravel 4项目中进行了几次迁移。一个是区域,另一个是区域。每个地区都有许多地区,地区属于地区。
我曾多次使用过Laravel 4和迁移功能,但之前从未遇到过这个问题。当我运行php artisan migrate:install
后跟php artisan migrate
时,我收到以下错误:
$ php artisan migrate
[Exception]
SQLSTATE[42000]: Syntax error or access violation: 1072 Key column 'region_
id' doesn't exist in table (SQL: alter table `areas` add constraint areas_r
egion_id_foreign foreign key (`region_id`) references `regions` (`id`)) (Bi
ndings: array (
))
migrate [--bench[="..."]] [--database[="..."]] [--path[="..."]] [--package[="...
"]] [--pretend] [--seed]
//区域迁移
class CreateRegionsTable extends Migration {
/**
* Run the migrations.
*
* @return void
*/
public function up()
{
// Creates the regions table
Schema::create('regions', function($table)
{
$table->engine = 'InnoDB';
$table->increments('id');
$table->string('name', 160)->unique();
$table->timestamps();
});
}
}
//区域迁移
class CreateAreasTable extends Migration {
/**
* Run the migrations.
*
* @return void
*/
public function up()
{
// Creates the cemeteries table
Schema::create('areas', function($table)
{
$table->engine = 'InnoDB';
$table->increments('id');
$table->foreign('region_id')->references('id')->on('regions');
$table->string('name', 160)->unique();
$table->timestamps();
});
}
}
答案 0 :(得分:17)
您必须创建与外键相关的列:
class CreateAreasTable extends Migration {
/**
* Run the migrations.
*
* @return void
*/
public function up()
{
// Creates the cemeteries table
Schema::create('areas', function($table)
{
$table->engine = 'InnoDB';
$table->increments('id');
$table->integer('region_id')->unsigned();
$table->foreign('region_id')->references('id')->on('regions');
$table->string('name', 160)->unique();
$table->timestamps();
});
}
}
有时(取决于您的数据库服务器)您必须分两步创建外键:
class CreateAreasTable extends Migration {
/**
* Run the migrations.
*
* @return void
*/
public function up()
{
// Create the table and the foreign key column
Schema::create('areas', function($table)
{
$table->engine = 'InnoDB';
$table->increments('id');
$table->integer('region_id')->unsigned();
$table->string('name', 160)->unique();
$table->timestamps();
});
// Create the relation
Schema::tabe('areas', function($table)
{
$table->foreign('region_id')->references('id')->on('regions');
});
}
}
答案 1 :(得分:4)
并且不要忘记将外键设为无符号。
$table->integer('region_id')->unsigned();