Laravel：在重新播种表之前重置自动增量
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Laravel: Reset auto increment before re-seeding a table
提问by rits
Is there a way to set auto increment back to 1 before seeding a table?
有没有办法在播种表之前将自动增量设置回 1？
I empty the table before seeding it and if I didn't do migrate:refreshbefore seeding it then it continues the auto increment of the ID from the last position, e.g., 4.
我在播种之前清空表格，如果我migrate:refresh在播种之前没有这样做，那么它会从最后一个位置继续自动增加 ID，例如 4。
Table seed:
表种子：
public function run()
{
DB::table('products')->delete();
// Product table seeder
$product = new \App\Product([
'category_id' => 1,
'image_path' => '/images/products/1/000001.jpg',
'title' => 'test',
]);
$product->save();
}
Creating the table:
创建表：
Schema::create('products', function (Blueprint $table) {
$table->increments('id');
$table->integer('category_id')->unsigned();
$table->foreign('category_id')->references('id')->on('categories');
$table->string('image_path');
$table->string('title');
$table->timestamps();
});
回答by Rimon Khan
Try this:
尝试这个：
DB::statement('SET FOREIGN_KEY_CHECKS=0');
DB::table('products')->truncate();
Instead of
代替
DB::table('products')->delete();
回答by Alexey Mezenin
If you're using make:migrationor make:model -mcommands to create a migration, Laravel is creating down()method with dropIfExists()clause:
如果您使用make:migration或make:model -m命令来创建迁移，Laravel 将down()使用dropIfExists()子句创建方法：
public function down()
{
Schema::dropIfExists('products');
}
So when you run migrate:refreshcommand, Laravel will drop the table and will recraete it for you.
因此，当您运行migrate:refresh命令时，Laravel 会删除该表并为您重新创建它。
Also, you have foreign keys in the table, so you need to use dropForeign()first:
此外，您在表中有外键，因此您需要先使用dropForeign()：
public function down()
{
Schema::table('products', function (Blueprint $table) {
$table->dropForeign('products_category_id_foreign');
});
Schema::dropIfExists('products');
}
