Fix/postgres duration migration (#251)

Author: Quentin Schmick

database/migrations/2019_09_25_103421_update_task_results_duration_type.php

@@ -1,6 +1,7 @@
 <?php
 
 use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Facades\Schema;
 use Studio\Totem\Database\TotemMigration;
 
@@ -13,10 +14,7 @@ class UpdateTaskResultsDurationType extends TotemMigration
      */
     public function up()
     {
-        Schema::connection(TOTEM_DATABASE_CONNECTION)
-            ->table(TOTEM_TABLE_PREFIX.'task_results', function (Blueprint $table) {
-                $table->decimal('duration', 24, 14)->charset('')->collation('')->change();
-            });
+        $this->migrateDurationValues();
     }
 
     /**
@@ -26,9 +24,49 @@ public function up()
      */
     public function down()
     {
+        $this->migrateDurationValues(false);
+    }
+
+    /**
+     * @param bool $toFloat
+     */
+    private function migrateDurationValues(bool $toFloat = true)
+    {
+        Schema::connection(TOTEM_DATABASE_CONNECTION)
+            ->table(TOTEM_TABLE_PREFIX.'task_results', function (Blueprint $table) {
+                // Move string duration column temporarily
+                $table->renameColumn('duration', 'duration_old');
+            });
+
+        Schema::connection(TOTEM_DATABASE_CONNECTION)
+            ->table(TOTEM_TABLE_PREFIX.'task_results', function (Blueprint $table) use ($toFloat) {
+                // Create new decimal column
+                if ($toFloat) {
+                    $table->decimal('duration', 24, 14)->default(0.0)->charset('')->collation('');
+                } else {
+                    $table->string('duration')->default('');
+                }
+            });
+
+        // Copy old duration data into new column
+        DB::connection(TOTEM_DATABASE_CONNECTION)
+            ->table(TOTEM_TABLE_PREFIX.'task_results')
+            ->select(['id', 'duration_old'])
+            ->chunkById(100, function ($rows) use ($toFloat) {
+                foreach ($rows as $row) {
+                    DB::connection(TOTEM_DATABASE_CONNECTION)
+                        ->table(TOTEM_TABLE_PREFIX)
+                        ->where('id', $row->id)
+                        ->update([
+                            'duration' => $toFloat ? floatval($row->duration_old) : (string) $row->duration_old,
+                        ]);
+                }
+            });
+
         Schema::connection(TOTEM_DATABASE_CONNECTION)
             ->table(TOTEM_TABLE_PREFIX.'task_results', function (Blueprint $table) {
-                $table->string('duration', 255)->change();
+                // Remove temp column
+                $table->dropColumn('duration_old');
             });
     }
 }