Fix very slow table display when filled with ugly data

app/Models/Row.php

@@ -31,17 +31,30 @@ class Row extends BaseModel
     public function scopeSortByCol(Builder $query, Column $column, $dir="asc")
     {
         $q = "data->>'".$column->id."'";
-        if ($column->type == 'int' || $column->type == 'float') {
-            $q = "CAST($q AS INTEGER)";
-        }
-        else if ($column->type == 'float') {
-            $q = "CAST($q AS FLOAT)";
-        }
 
-        if ($dir == 'asc') {
-            $q .= ' ASC';
-        } else {
-            $q .= ' DESC';
+        $dir = strtoupper($dir);
+
+        switch ($column->type) {
+            case 'int':
+                $q = "CAST($q AS INTEGER) $dir";
+                break;
+
+            case 'float':
+                $q = "CAST($q AS FLOAT) $dir";
+                break;
+
+            case 'string':
+                // Without a size restriction and a cast, this query becomes VERY slow
+                $q = "CAST($q AS CHAR(25)) $dir, data->>'_id' $dir";
+                // added _id as a fallback to ensure the order is the same between revisions
+                break;
+
+            case 'bool':
+                $q = "CAST($q AS boolean) $dir";
+                break;
+
+            default:
+                throw new \LogicException("Missing SQL cast for column type $column->type, performance will suffer.");
         }
 
         return $query->orderByRaw($q);