laravel 5 - 如何将 ->index() 添加到现有外键
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laravel 5 - How can i add ->index() to existing foreign key
提问by Dani Banai
Framework: Laravel 5.2 Database: MySQL PHP: 7.0
框架：Laravel 5.2 数据库：MySQL PHP：7.0
I have the table "pops":
我有桌子“弹出”：
Schema::create('pops', function (Blueprint $table) {
$table->string('id')->primary()->index();
$table->string('ab_test_parent_id')->nullable();
$table->string('cloned_parent_id')->nullable();
$table->timestamps();
});
And the table "conversions":
表“转换”：
Schema::create('conversions', function (Blueprint $table) {
$table->string('id')->primary()->index();
$table->integer('users')->default(null);
$table->string('name',256)->default(null);
$table->string('pop_id');
$table->foreign('pop_id')->references('id')->on('pops')->onDelete('cascade')->onUpdate('cascade');
$table->timestamps();
});
I have set a foreign key (pop_id) in the "conversions" table. Now does it's mean that the foreign key (pop_id) is also a index? if not... what i need to do in order to make it a index?
我在“conversions”表中设置了一个外键（pop_id）。现在这是否意味着外键（pop_id）也是一个索引？如果没有...我需要做什么才能使它成为索引？
Thank?
谢谢？
回答by chebaby
You can just do this.
你可以这样做。
<?php
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;
class AddIndexToLeads extends Migration {
/**
* Run the migrations.
*
* @return void
*/
public function up()
{
Schema::table('leads', function(Blueprint $table)
{
$table->index('trader_id');
});
}
/**
* Reverse the migrations.
*
* @return void
*/
public function down()
{
Schema::table('leads', function (Blueprint $table)
{
$table->dropIndex(['trader_id']);
});
}
}
credit to @bobbybouwmann
回答by Sandeesh
Laravel only adds a foreign key constraint and doesn't add index implicitly. But some databases such as MySQL automatically index foreign key columns.
Laravel 只添加了外键约束，并没有隐式添加索引。但有些数据库如 MySQL 会自动索引外键列。
If you need to add index to a field in another migration. Then you could do
如果您需要为另一个迁移中的字段添加索引。那么你可以做
$table->index('email');
回答by zarpio
Here is a perfect solution for you.
这里有一个完美的解决方案。
Up
向上
$table->string('poptin_id')->index('poptin_id');
Down
下
$table->dropIndex(['poptin_id']);
Suggestion to fix your migrations
修复迁移的建议
$table->string('id')->primary()->index();
replace above with below
用下面替换上面
$table->increments('id');
and fix your foreign key as below
并修复您的外键如下
$table->integer('poptin_id')->index('poptin_id')->unsigned();
回答by Vipertecpro
I was facing problem when i just write :-
我刚写的时候遇到了问题：-
$table->index('column_name');
So to be more exact first you need to create column with desired column type then assign it to be indexlike this :-
因此，更准确地说，您首先需要创建具有所需列类型的列，然后将其分配为这样的索引：-
$table->string('column_name');
$table->index('column_name');
//or
$table->string('column_name')->index();
I hope this helps
我希望这有帮助
