完整性约束违规：1451无法删除或更新父行：外键约束失败 - Laravel

Question

运行PHP工匠迁移后，我会遇到此错误。

  SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (SQL: drop table if exists `products`)

create_products_table.php

public function up()
    {
        Schema::dropIfExists('products');
        Schema::create('products', function (Blueprint $table) {
            $table->id();
            $table->string('name');
            //  Other attributes here
            
            $table->bigInteger('ctg_id')->unsigned();
            $table->bigInteger('product_variation_id')->unsigned();  
            $table->bigInteger('sub_ctg_id')->unsigned();
            $table->bigInteger('vehicle_id')->unsigned();  

            $table->foreign('ctg_id')->references('id')->on('ctgs')->constrained()->onDelete('cascade')->onUpdate('cascade');
            $table->foreign('product_variation_id')->references('id')->on('product_variations')->constrained()->onDelete('cascade')->onUpdate('cascade');
            $table->foreign('sub_ctg_id')->references('id')->on('sub_ctgs')->constrained()->onDelete('cascade')->onUpdate('cascade');
            $table->foreign('vehicle_id')->references('id')->on('vehicles')->constrained()->onDelete('cascade')->onUpdate('cascade');
            $table->timestamps();
        });
    }
    public function down()
    {
        Schema::dropIfExists('products');
    }

我在线搜索，获得了此解决方案，相应地更改了代码，但徒劳无功 https://stackoverflow.com/a/47544195/7290043

现在，我我只是用下表工作

Answer 1

您必须在删除表之前使用$ table-＆gt; dropforeign（），请删除外部键以避免此错误。