修改connecttion和belongsTo若干文档注释错误

library/think/db/Connection.php

@@ -338,8 +338,8 @@ abstract class Connection
      * @param bool          $master 是否在主服务器读操作
      * @param bool          $pdo 是否返回PDO对象
      * @return mixed
-     * @throws BindParamException
      * @throws PDOException
+     * @throws \Exception
      */
     public function query($sql, $bind = [], $master = false, $pdo = false)
     {
@@ -400,8 +400,8 @@ abstract class Connection
      * @param string        $sql sql指令
      * @param array         $bind 参数绑定
      * @return int
-     * @throws BindParamException
      * @throws PDOException
+     * @throws \Exception
      */
     public function execute($sql, $bind = [])
     {
@@ -552,7 +552,7 @@ abstract class Connection
      * @access protected
      * @param bool   $pdo 是否返回PDOStatement
      * @param bool   $procedure 是否存储过程
-     * @return array
+     * @return PDOStatement|array
      */
     protected function getResult($pdo = false, $procedure = false)
     {
@@ -618,7 +618,8 @@ abstract class Connection
     /**
      * 启动事务
      * @access public
-     * @return void
+     * @return bool|mixed
+     * @throws \Exception
      */
     public function startTrans()
     {
@@ -782,7 +783,7 @@ abstract class Connection
     /**
      * 是否断线
      * @access protected
-     * @param \PDOException  $e 异常对象
+     * @param \PDOException|\Exception  $e 异常对象
      * @return bool
      */
     protected function isBreak($e)