laravel 5.6 Illuminate\Database\QueryException : SQLSTATE[42000]

create_properties_table-v0.php

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreatePropertiesTable extends Migration {

const TABLE_NAME = 'properties';

  /**
   * Run the migrations.
   *
   * @return void
   */
  public function up() {
    Schema::create(self::TABLE_NAME, function (Blueprint $table) {
      $table->increments('id');
      $table->integer('seller_id'); // users table FK
      $table->char('property_type', 50);
      $table->char('apartment_type', 25);
      $table->char('measurement', 10);
      $table->char('measurement_type', 20);
      $table->char('maintenance_charges', 10)->nullable();
      $table->char('ownership', 20); // Individual, Joint
      $table->char('joint_owners_name', 100)->nullable();
      $table->integer('sale_price', 10); // <---------------------------- This line creates problem
      $table->integer('min_expected_price', 10)->nullable(); // <---------------------------- This line creates problem
      $table->string('address', 500);
      $table->string('homeloan_details', 500)->nullable();
      $table->string('amenities', 800)->nullable();
      $table->text('locality_features')->nullable();
      $table->timestamps();
    });
  }

  /**
   * Reverse the migrations.
   *
   * @return void
   */
  public function down() {
    Schema::dropIfExists(self::TABLE_NAME);
  }
}

create_properties_table-v1.php

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreatePropertiesTable extends Migration {

const TABLE_NAME = 'properties';

  /**
   * Run the migrations.
   *
   * @return void
   */
  public function up() {
    Schema::create(self::TABLE_NAME, function (Blueprint $table) {
      $table->increments('id');
      $table->integer('seller_id'); // users table FK
      $table->char('property_type', 50);
      $table->char('apartment_type', 25);
      $table->char('measurement', 10);
      $table->char('measurement_type', 20);
      $table->char('maintenance_charges', 10)->nullable();
      $table->char('ownership', 20); // Individual, Joint
      $table->char('joint_owners_name', 100)->nullable();
      $table->integer('sale_price'); // <---------------------------- problem fixed
      $table->integer('min_expected_price')->nullable(); // <---------------------------- problem fixed
      $table->string('address', 500);
      $table->string('homeloan_details', 500)->nullable();
      $table->string('amenities', 800)->nullable();
      $table->text('locality_features')->nullable();
      $table->timestamps();
    });
  }

  /**
   * Reverse the migrations.
   *
   * @return void
   */
  public function down() {
    Schema::dropIfExists(self::TABLE_NAME);
  }
}

migration-issue

Illuminate\Database\QueryException  : SQLSTATE[42000]: Syntax error or access violation: 1075 Incorrect table definition; t
here can be only one auto column and it must be defined as a key 
(SQL: create table `properties` (`id` int unsigned not null auto_increment primary key, `seller_id` int not null, `
property_type` char(50) not null, `apartment_type` char(25) not null, `measurement` char(10) not null, 
`measurement_type` char(20) not null, `maintenance_charges` char(10) null, `ownership` char(20) not null, 
`joint_owners_name` char(100) null, `sale_price` int not null auto_increment primary key, 
`min_expected_price` int null auto_increment primary key, `address` varchar(500) not null, 
`homeloan_details` varchar(500) null, `amenities` varchar(800) null, `locality_features` text null, 
`created_at` timestampnull, `updated_at` timestamp null) default character set utf8mb4 collate utf8mb4_unicode_ci)

  at /var/www/html/sale-my-house/vendor/laravel/framework/src/Illuminate/Database/Connection.php: 664
    660|         // If an exception occurs when attempting to run a query, we'll format the error
    661|         // message to include the bindings with SQL, which will make this exception a
    662|         // lot more helpful to the developer instead of just the database's errors.
    663|         catch (Exception $e) {
  > 664|             throw new QueryException(
    665|                 $query, $this->prepareBindings($bindings), $e
    666|             );
    667|         }
    668|

I suggest to use the type decimal() when it's price: $table->decimal('price', 10,2).

Case want to integer, change integer() to smallInteger().
$table->smallInteger('sale_price');
$table->smallInteger('min_expected_price')->nullable();

See https://laravel.com/docs/5.8/migrations#columns