运行 "php artisan migrate" 包含主键和外键的迁移文件出现语法错误或访问冲突错误

Question

您好，我正在尝试在我的数据库中创建 2 个名为 "brand" 和 "product" 的表。我为 "brand" 创建了名为 "create_brand" 的迁移文件，其中包含：

public function up()
{
    Schema::create('brand', function($table){
        $table->increments('brand_id');
        $table->string('brand_name', 100);
    });
}

/**
 * Reverse the migrations.
 *
 * @return void
 */
public function down()
{
    Schema::drop('brand');
}

"product" 的名为 "create_product" 的迁移文件包含：

public function up()
{
    Schema::create('product', function($table){
        $table->increments('skuid');
        $table->integer('brand_id')->unasigned();
    });

    Schema::create('product', function($table){
        $table->foreign('brand_id')->references('brand_id')->on('brand')->onDelete('cascade');
    });


}

/**
 * Reverse the migrations.
 *
 * @return void
 */
public function down()
{
    Schema::table('product', function($table){
        $table->dropForeign('brand_id');
    });

    Schema::drop('product');
}

现在当我运行 "php artisan migrate" 我得到错误：

  [Illuminate\Database\QueryException]
  SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error i
  your SQL syntax; check the manual that corresponds to your MySQL server v
  ersion for the right syntax to use near ') default character set utf8 colla
  te utf8_unicode_ci' at line 1 (SQL: create table `product` () default chara
  cter set utf8 collate utf8_unicode_ci)


  [PDOException]
  SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error i
  n your SQL syntax; check the manual that corresponds to your MySQL server v
  ersion for the right syntax to use near ') default character set utf8 colla
  te utf8_unicode_ci' at line 1

如果有人能帮我解决这个问题，我将不胜感激:) 谢谢。

Answer 1

只使用一次Schema::create。要编辑 table 使用 Schema::table

并且当使用外键时类型应该是unsignedInteger。如果您创建一个基本整数并尝试在其上放置外键，它将失败。

将您的代码更改为

public function up()
{
    Schema::create('product', function($table){
       $table->increments('skuid');
       $table->unsignedInteger('brand_id');
    });

    Schema::table('product', function($table){
       $table->foreign('brand_id')->references('brand_id')->on('brand');
    });
}

/**
* Reverse the migrations.
*
* @return void
*/
public function down()
{
    Schema::drop('product');
}

Answer 2

对我来说，下面的代码 100% 有效。
在AppServiceProvider.php

use Illuminate\Support\Facades\Schema;
public function boot()
{
    Schema::defaultStringLength(191);
}

运行 "php artisan migrate" 包含主键和外键的迁移文件出现语法错误或访问冲突错误

Syntax error or access violation error while running "php artisan migrate" for migration file containing primary & foreign keys

migration

laravel