Laravel 5.5迁移失败：将列数据类型字符串更新为json

Question

When I migrate my db I get a error on updating a table column from string to JSON.

The column value is like:

{"images":["/vendors/57/horse-16.png"]}

I checked if this is a valid JSON and that looks good to me..

My migration file is:

public function up()
{
    Schema::table('vendor_horses', function (Blueprint $table) {
        $table->json('image')->change();
    });
}

My error in Laravel:

SQLSTATE[42000]: Syntax error or access violation: 1253 COLLATION 'utf8mb4_  
      unicode_ci' is not valid for CHARACTER SET 'binary' (SQL: ALTER TABLE vendo  
      r_horses CHANGE image image JSON DEFAULT NULL COLLATE utf8mb4_unicode_ci)    

I don't know what's wrong, the strings are json correct so why does the update fails?

Answer 1

I dig some issues related to the error in Github and found that when changing into a JSON field, the collation should be set to an empty string and this issue will be solved. So you can try by changing the below code:

$table->json('image')->change();

to

$table->json('image')->customSchemaOptions(['collation' => ''])->change();

For more details you can check this issue