How to dynamically disable and enable foreign key check in laravel? - php

Question

I am trying to move entries from my old tables to the new one with the updated schema. The problem is, I have to move content from 10 tables with old config to 10 tables with the new config.
I am doing this with the help of console command. When I add the new table and execute the command, I get Duplicate entry error for the tables that already have data which is obvious.
When I try to use DB::connection('mysql_old')->table('users')->truncate();, It throws 1701 Cannot truncate a table referenced in a foreign key constraint Errror which is obvious too!
Here is how I am moving entries from old tables to the new one.
$entries = DB::connection('mysql_old')->table('users')->get();
DB::table('users')->truncate();
foreach($entries as $entry){
$user = \App\User::create([
'name' => $entry->name,
'email' => $entry->email,
'status' => $entry->status,
'credits' => $entry->credits,
'role' => $entry->user_role,
'email_subscription' => $entry->email_subscription,
'activation_key' => $entry->activation_key,
'password' => $entry->password,
'remember_token' => $entry->remember_token,
'created_at' => $entry->created_at,
'updated_at' => $entry->updated_at
]);
}
The only solution is to disable foreign key check before truncate and enable it again after truncate (I think). It is a relational database as obvious. So, is there any better way to complete this task?
I thought about giving a try to move entries from old table to the new one in a relational way but it is not possible in this case.
I can execute the command php artisan migrate:refresh every time the command is executed. But here is the problem with that, There are more than 25 tables and It takes about 20-30 seconds to complete migrate:refresh.
I am really confused how to get this done. Is there any proper or standard way?

Answer 1

You can do this:
Schema::disableForeignKeyConstraints();
// Your database operations go here..
Schema::enableForeignKeyConstraints();

Answer 2

Finally, I found the solution to turn off and turn on the foreign key check. Here is how I moved information from old table to new one.
// Disable foreign key checks!
DB::statement('SET FOREIGN_KEY_CHECKS=0;');
// Move users from old table to the new one
$entries = DB::connection('mysql_old')->table('users')->get();
DB::table('users')->truncate();
foreach($entries as $entry){
$user = \App\User::create([
'name' => $entry->name,
'email' => $entry->email,
'status' => $entry->status,
'credits' => $entry->credits,
'role' => $entry->user_role,
'email_subscription' => $entry->email_subscription,
'activation_key' => $entry->activation_key,
'password' => $entry->password,
'remember_token' => $entry->remember_token,
'created_at' => $entry->created_at,
'updated_at' => $entry->updated_at
]);
}
// Enable foreign key checks!
DB::statement('SET FOREIGN_KEY_CHECKS=1;');
It worked!

Answer 3

if you have migration table just make index to attribut like this:
just make ->index
like this
$table->unsignedBigInteger('city_id')->index();
$table->foreign('city_id')->references('id')
->on('cities')->onDelete('cascade');