Fixes/integrity constraint (#6755)

* Migration to fix nullables

This should fix an issue introduced in 90cddb7aee where we’re passing null instead of an empty string (necessary to nullify values via the API)

* Removed asset migration - serial was already fixed

database/migrations/2019_02_21_224703_make_fields_nullable_for_integrity.php

@@ -0,0 +1,64 @@
+<?php
+
+use Illuminate\Support\Facades\Schema;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Database\Migrations\Migration;
+
+class MakeFieldsNullableForIntegrity extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+
+
+        Schema::table('locations', function (Blueprint $table) {
+            $table->string('city')->nullable()->default(null)->change();
+            $table->string('state')->nullable()->default(null)->change();
+            $table->string('country')->nullable()->default(null)->change();
+            $table->integer('user_id')->nullable()->default(null)->change();
+            $table->string('address')->nullable()->default(null)->change();
+            $table->string('address2')->nullable()->default(null)->change();
+        });
+
+        Schema::table('users', function (Blueprint $table) {
+            $table->string('last_name')->nullable()->default(null)->change();
+        });
+
+        Schema::table('suppliers', function (Blueprint $table) {
+            $table->integer('user_id')->nullable()->default(null)->change();
+        });
+
+        Schema::table('status_labels', function (Blueprint $table) {
+            $table->integer('user_id')->nullable()->default(null)->change();
+        });
+
+        Schema::table('models', function (Blueprint $table) {
+            $table->integer('user_id')->nullable()->default(null)->change();
+            $table->integer('manufacturer_id')->nullable()->default(null)->change();
+            $table->integer('category_id')->nullable()->default(null)->change();
+        });
+
+        Schema::table('licenses', function (Blueprint $table) {
+            $table->integer('user_id')->nullable()->default(null)->change();
+            $table->boolean('maintained')->nullable()->default(null)->change();
+        });
+
+        Schema::table('depreciations', function (Blueprint $table) {
+            $table->integer('user_id')->nullable()->default(null)->change();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        //
+    }
+}