Php Laravel迁移引发数据库查询异常错误

我正在尝试编写一个具有外部关系的laravel数据库迁移。数据库迁移期间引发查询异常错误

我厌倦了使用laravel规则迁移表，但在迁移过程中，它显示了意外错误

用户表

    Schema::create('users', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('name', 150);
        $table->string('email', 150)->unique();
        $table->timestamp('email_verified_at')->nullable();
        $table->string('phone', 150);
        $table->unsignedBigInteger('role_id');
        $table->foreign('role_id')->references('id')->on('roles')->onDelete('cascade');
        $table->string('password');
        $table->rememberToken();
        $table->timestamps();
    });

    Schema::create('roles', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('role_name',255);
        $table->longText('role_description',255);
        $table->integer('sort_order');
        $table->enum('status',['A','I','D'])->comment('A-active','I-inactive,D-delete'); 
        $table->enum('is_deleted',['Y','N'])->comment('Y-yes,N-no');
        $table->timestamps();
        $table->bigInteger('created_by');
        $table->bigInteger('updated_by')->default(0);
        $table->bigInteger('deleted_by')->default(0);
        $table->timestamp('deleted_at')->nullable();
    });

角色表

    Schema::create('users', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('name', 150);
        $table->string('email', 150)->unique();
        $table->timestamp('email_verified_at')->nullable();
        $table->string('phone', 150);
        $table->unsignedBigInteger('role_id');
        $table->foreign('role_id')->references('id')->on('roles')->onDelete('cascade');
        $table->string('password');
        $table->rememberToken();
        $table->timestamps();
    });

    Schema::create('roles', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('role_name',255);
        $table->longText('role_description',255);
        $table->integer('sort_order');
        $table->enum('status',['A','I','D'])->comment('A-active','I-inactive,D-delete'); 
        $table->enum('is_deleted',['Y','N'])->comment('Y-yes,N-no');
        $table->timestamps();
        $table->bigInteger('created_by');
        $table->bigInteger('updated_by')->default(0);
        $table->bigInteger('deleted_by')->default(0);
        $table->timestamp('deleted_at')->nullable();
    });

Illumb\Database\QueryException:SQLSTATE[HY000]：一般错误： 1215无法添加外键约束（SQL:alter table

jt_users

添加约束

users\u role\u id\u foreign

外键（

role\u id

） 删除级联上的引用

jt_角色

（

id

）

---

不能将外键添加到不存在的表中。在本例中，您正在尝试在创建

角色

表之前创建

角色_id

在

角色

表迁移中，创建

角色

表后，您需要更新

用户

表：

Schema::create('roles', function (Blueprint $table) {
    $table->bigIncrements('id');
    $table->string('role_name',255);
    $table->longText('role_description',255);
    $table->integer('sort_order');
    $table->enum('status',['A','I','D'])->comment('A-active','I-inactive,D-delete'); 
    $table->enum('is_deleted',['Y','N'])->comment('Y-yes,N-no');
    $table->timestamps();
    $table->bigInteger('created_by');
    $table->bigInteger('updated_by')->default(0);
    $table->bigInteger('deleted_by')->default(0);
    $table->timestamp('deleted_at')->nullable();
});

Schema::table('users', function (Blueprint $table) {
    $table->unsignedBigInteger('role_id');
    $table->foreign('role_id')->references('id')->on('roles')->onDelete('cascade');
});

注意：对表进行更改时，请使用

Schema:：table（）

而不是

Schema:：create（）

在

roles

迁移的

down（）

方法中，您需要删除外键和字段：

Schema::table('users', function (Blueprint $table) {
    $table->dropForeign(['role_id']);
    $table->dropColumn('role_id');
});

---

首先，必须迁移具有“主键”（users）的表

在用户迁移中，您似乎没有为

角色\u id

定义列定义。迁移顺序也很重要。。。您必须确保首先运行角色迁移。