How to remove unique constraint from a column using Laravel migrations?

Question

I have to remove a unique constraint from an email column using Laravel migrations. Here is my code:

class AlterEmailToUsers extends Migration
{
/**
 * Run the migrations.
 *
 * @return void
 */
public function up()
{
    Schema::table('users', function (Blueprint $table) {
        $table->string('email')->unique(false)->nullable()->change();
    });
}

/**
 * Reverse the migrations.
 *
 * @return void
 */
public function down()
{
    Schema::table('users', function (Blueprint $table) {
       $table->string('email')->nullable(false)->unique()->change();
    });
}

}

But when I run php artisan migrate, I get the following error:

SQLSTATE[42000]: Syntax error or access violation: 1061 Duplicate key name 'users_email_unique' (SQL: alter table `users` add unique `users_email_unique`(`email`))

to remove the index, `$table->dropUnique('email');` Drop a unique index from the "users" table., Refer [here](https://laravel.com/docs/5.6/migrations#dropping-indexes) — iamab.in, Apr 13 '18 at 07:49

Kuldeep Mishra · Accepted Answer · 2018-04-13T07:54:32.790

35

 public function up()
 {
   Schema::table('users', function (Blueprint $table) {
    $table->string('email')->unique(false)->nullable()->change();
   });
  }

change to

$table->dropUnique('users_email_unique');

edited Apr 13 '18 at 07:54

answered Apr 13 '18 at 07:49

Kuldeep Mishra

3,846
1
21
26

Its not working. Problem is not in down method, problem is somewhere in up method. I am editing my question. Please review my question too. – aishazafar Apr 13 '18 at 07:52
I need to ask something about the same migration. Should I ask here or should I create new question for it. – aishazafar Apr 13 '18 at 08:29
I want to make the same field nullable to in the same step. but its not working in one step. – aishazafar Apr 13 '18 at 08:40
Please give me few minutes. – aishazafar Apr 13 '18 at 08:50
Its working thank you so much for your help @Kuldeep Mishra – aishazafar Apr 13 '18 at 08:55

score 23 · Answer 2 · answered Apr 06 '21 at 04:59

23

The provided solution works just fine but just one small tip here:
You can pass an array with the name of the column like so:

$table->dropUnique(['email']);

in this case, Laravel will generate the index name automatically based on its conventions

answered Apr 06 '21 at 04:59

4unkur

827
9
14

Rodrigo Carvalho de Brito · Answer 3 · 2022-07-11T13:51:11.607

2

I went through this problem, when using softDeletes on all tables, which caused this need, for new users, once deleted logically.

So, I created a migration by setting the users table (--table=users) and placed the removal of the constraint, but then I redid the action for possible new inclusion needs.

But I used it only because of the softDeletes, be careful with your business rules. I keep validating existence in request rules.

The code is as follows (up and down methods only):

public function up()
{
    Schema::table('users', function (Blueprint $table) {
        $table->dropUnique(['email']);
    });
}


public function down()
{
    Schema::table('users', function (Blueprint $table) {
        $table->unique(['email']);
    });
}

edited Jul 11 '22 at 13:51

answered Jul 10 '22 at 13:29

Rodrigo Carvalho de Brito

121
4

While this code may solve the question, [including an explanation](https://meta.stackexchange.com/q/114762) of how and why this solves the problem would really help to improve the quality of your post, and probably result in more up-votes. Remember that you are answering the question for readers in the future, not just the person asking now. Please [edit] your answer to add explanations and give an indication of what limitations and assumptions apply. – Jeremy Caney Jul 11 '22 at 01:26

How to remove unique constraint from a column using Laravel migrations?

3 Answers3