Add PostgreSQL Support (#3)

Reviewed-on: #3

src/Query/Count.php

@@ -33,4 +33,28 @@ class Count
     {
         return self::all($tableName) . ' WHERE ' . Query::whereByFields($fields, $match);
     }
+
+    /**
+     * Query to count matching documents using a JSON containment query (PostgreSQL only)
+     *
+     * @param string $tableName The name of the table in which documents should be counted
+     * @return string The query to count documents using a JSON containment query
+     * @throws DocumentException If the database mode is not PostgreSQL
+     */
+    public static function byContains(string $tableName): string
+    {
+        return self::all($tableName) . ' WHERE ' . Query::whereDataContains();
+    }
+
+    /**
+     * Query to count matching documents using a JSON Path match (PostgreSQL only)
+     *
+     * @param string $tableName The name of the table in which documents should be counted
+     * @return string The query to count documents using a JSON Path match
+     * @throws DocumentException If the database mode is not PostgreSQL
+     */
+    public static function byJsonPath(string $tableName): string
+    {
+        return self::all($tableName) . ' WHERE ' . Query::whereJsonPathMatches();
+    }
 }