Ensured latitude and longitude are set as float in DB

data/migrations/Version20200105165647.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ShlinkMigrations;
+
+use Doctrine\DBAL\DBALException;
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\DBAL\Types\Type;
+use Doctrine\DBAL\Types\Types;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20200105165647 extends AbstractMigration
+{
+    private const COLUMNS = ['latitude', 'longitude'];
+
+    public function preUp(Schema $schema): void
+    {
+        foreach (self::COLUMNS as $columnName) {
+            $qb = $this->connection->createQueryBuilder();
+            $qb->update('visit_locations')
+               ->set($columnName, '"0"')
+               ->where($columnName . '=""')
+               ->orWhere($columnName . ' IS NULL')
+               ->execute();
+        }
+    }
+
+    /**
+     * @throws DBALException
+     */
+    public function up(Schema $schema): void
+    {
+        $visitLocations = $schema->getTable('visit_locations');
+
+        foreach (self::COLUMNS as $columnName) {
+            $visitLocations->getColumn($columnName)->setType(Type::getType(Types::FLOAT));
+        }
+    }
+
+    /**
+     * @throws DBALException
+     */
+    public function down(Schema $schema): void
+    {
+        $visitLocations = $schema->getTable('visit_locations');
+
+        foreach (self::COLUMNS as $columnName) {
+            $visitLocations->getColumn($columnName)->setType(Type::getType(Types::STRING));
+        }
+    }
+}

module/Core/config/entities-mappings/Shlinkio.Shlink.Core.Entity.VisitLocation.php

@@ -25,14 +25,22 @@ $columns = [
     'country_name' => 'countryName',
     'region_name' => 'regionName',
     'city_name' => 'cityName',
-    'latitude' => 'latitude',
-    'longitude' => 'longitude',
     'timezone' => 'timezone',
 ];
 
 foreach ($columns as $columnName => $fieldName) {
     $builder->createField($fieldName, Type::STRING)
-        ->columnName($columnName)
+            ->columnName($columnName)
+            ->nullable()
+            ->build();
+}
+
+$builder->createField('latitude', Type::FLOAT)
+        ->columnName('latitude')
+        ->nullable()
+        ->build();
+
+$builder->createField('longitude', Type::FLOAT)
+        ->columnName('longitude')
         ->nullable()
         ->build();
-}

module/Core/src/Entity/Visit.php

@@ -15,10 +15,10 @@ use Shlinkio\Shlink\Core\Visit\Model\VisitLocationInterface;
 
 class Visit extends AbstractEntity implements JsonSerializable
 {
-    private string $referer;
+    private string $referer = '';
     private Chronos $date;
-    private ?string $remoteAddr;
-    private string $userAgent;
+    private ?string $remoteAddr = null;
+    private string $userAgent = '';
     private ShortUrl $shortUrl;
     private ?VisitLocation $visitLocation = null;