MySQL Laravel 无法删除或更新父行：外键约束失败
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Laravel Cannot delete or update a parent row: a foreign key constraint fails
提问by BARNOWL
For some reason a user cannot delete a post if it has been liked, it was working before but when I linked posts with likes I have been getting this error, I can't even delete it in Sequel Pro, unless I delete the likes associated with the post first.
出于某种原因，用户无法删除已被喜欢的帖子，它以前可以使用，但是当我将帖子与喜欢的链接链接时，我收到此错误，我什至无法在 Sequel Pro 中删除它，除非我删除相关的喜欢先用帖子。
Error
错误
SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (
eliapi8.likes, CONSTRAINTlikes_post_id_foreignFOREIGN KEY (post_id) REFERENCESposts(id)) (SQL: delete frompostswhereid= 149)
SQLSTATE[23000]: 完整性约束违规：1451 无法删除或更新父行：外键约束失败 (
eliapi8.likes, CONSTRAINTlikes_post_id_foreignFOREIGN KEY (post_id) REFERENCESposts(id)) (SQL: delete frompostswhereid= 149)
Maybe it's my schema?
也许这是我的架构？
Posts Schema
帖子架构
Schema::create('posts', function (Blueprint $table) {
$table->increments('id');
$table->string('title');
$table->text('body');
$table->integer('user_id')->unsigned();
$table->foreign('user_id')->references('id')->on('users');
$table->timestamps();
});
Likes Schema
喜欢架构
Schema::create('likes', function (Blueprint $table) {
$table->increments('id');
$table->integer('post_id')->unsigned();
$table->integer('user_id')->unsigned();
$table->foreign('post_id')->references('id')->on('posts');
$table->foreign('user_id')->references('id')->on('users');
$table->softDeletes();
$table->timestamps();
});
I can like and unlike a post, but a user cannot delete a post that has been liked.
我可以喜欢和不喜欢帖子，但用户不能删除已喜欢的帖子。
PostController.php
后控制器.php
public function destroy(Post $post){
$this->authorize('delete', $post);
$postl = Post::with('likes')->whereId($post)->delete();
if ($post->delete()) {
if($postl){
return response()->json(['message' => 'deleted']);
}
};
return response()->json(['error' => 'something went wrong'], 400);
}
回答by Camilo
Yes, it's your schema. The constraint on likes.post_idwill prevent you from deleting records from the poststable.
是的，这是您的架构。的约束likes.post_id将阻止您从posts表中删除记录。
One solution could be using onDelete('cascade')in the likesmigration file:
一种解决方案可能是onDelete('cascade')在likes迁移文件中使用：
Schema::create('likes', function (Blueprint $table) {
// Some other fields...
$table->integer('post_id')->unsigned();
$table->foreign('post_id')->references('id')->on('posts')->onDelete('cascade');
});
This way, when a post is deleted, all related likes will be deleted too.
这样，当帖子被删除时，所有相关的赞也将被删除。
Or, if you have a relationship from the Post model to the Like model, you can $post->likes()->delete()before deleting the post itself.
或者，如果您有 Post 模型和 Like 模型的关系，您可以$post->likes()->delete()在删除帖子本身之前。
