改进数据库连接配置 支持dsn配置

src/Connection.php

@@ -185,13 +185,15 @@ public function connect(array $config = [], $linkNum = 0)
                 $this->config['pk'] = 'id';
             }
 
-            $host = 'mongodb://' . ($config['username'] ? "{$config['username']}" : '') . ($config['password'] ? ":{$config['password']}@" : '') . $config['hostname'] . ($config['hostport'] ? ":{$config['hostport']}" : '');
+            if (empty($config['dsn'])) {
+                $config['dsn'] = 'mongodb://' . ($config['username'] ? "{$config['username']}" : '') . ($config['password'] ? ":{$config['password']}@" : '') . $config['hostname'] . ($config['hostport'] ? ":{$config['hostport']}" : '');
+            }
 
             if ($config['debug']) {
                 $startTime = microtime(true);
             }
 
-            $this->links[$linkNum] = new Manager($host, $this->config['params']);
+            $this->links[$linkNum] = new Manager($config['dsn'], $config['params']);
 
             if ($config['debug']) {
                 // 记录数据库连接信息
@@ -829,7 +831,7 @@ public function update(Query $query)
         $pk = $query->getPk($options);
 
         if (empty($options['where'])) {
-            if ($this->getConfig('pk_convert_id') && $pk == '_id') {
+            if ($this->getConfig('pk_convert_id') && '_id' == $pk) {
                 $pk = 'id';
             }
 
@@ -887,7 +889,7 @@ public function update(Query $query)
 
             $query->trigger('after_update');
         }
-        
+
         $query->setOption('where', []);
 
         return $result;