如何在不使用Laravel中任何关系的情况下删除多表数据库中的数据

Question

I have 2 table in my database.

first is table post

Schema::create('posts', function (Blueprint $table) {
        $table->increments('id');
        $table->date('PostDate');
        $table->string('PostTitle', 200);
        $table->string('GroupID', 100)->nullable();
        $table->integer('LanguageID')->default(1);
        $table->timestamps();
    });

second is table post_categories

Schema::create('post_categories', function (Blueprint $table) {
        $table->integer('post_id');
        $table->integer('category_id');
        $table->timestamps();
    });

Every time I store post data into database, it will stored as two rows.. because I have two active language. In my post_categories table, there has category_id column.. So, if the post data with id = 1 has 2 categories.. and the post data with id = 2 has 3 categories, it will create 5 rows in post_categories table. But when I want to delete the post, I will check from the group ID first.. So, I will delete 2 rows too.. But the problem is, I can not delete the data in post_categories.. I have using foreach but the data won't be deleted..

This is my delete Controller:

public function destroy($id)
{
    $post = Post::findOrFail($id);
    Post::where('GroupID', $post->GroupID)->delete();
    $postGroups = Post::where('GroupID', $post->GroupID)->get();
    foreach ($postGroups as $postGroup) {
        DB::table('post_categories')->where('post_id', $postGroup->id)->delete();
    }

    return response()->json([
        "error" => "0",
        "message" => "Success"
    ]);
}

I can delete all the post with same group ID, but I can not delete the post_categories data that has same post_id.

Answer 1

You've already chosen the answer, but in your case it's much better to use whereIn() :

$post = Post::findOrFail($id);
$postGroups = Post::where('GroupID', $post->GroupID)->get();
DB::table('post_categories')->whereIn('post_id', $postGroups->pluck('id'))->delete();
Post::where('GroupID', $post->GroupID)->delete();

Answer 2

Delete the categories before deleting the post.

public function destroy($id)
{
    $post = Post::findOrFail($id);

    $postGroups = Post::where('GroupID', $post->GroupID)->get();
    foreach ($postGroups as $postGroup) {
        DB::table('post_categories')->where('post_id', $postGroup->id)->delete();
    }

    Post::where('GroupID', $post->GroupID)->delete();

    return response()->json([
        "error" => "0",
        "message" => "Success"
    ]);

}

In order to have a better code experience, I recommend using a table structure like posts , posts_categories and posts_languages . This last one will contain the data regarding the content in multiple languages, and will be related to posts