diff --git a/library/think/db/connector/Mysql.php b/library/think/db/connector/Mysql.php
index 31435694..0a14e48e 100644
--- a/library/think/db/connector/Mysql.php
+++ b/library/think/db/connector/Mysql.php
@@ -21,6 +21,8 @@ use think\Log;
 class Mysql extends Connection
 {
 
+    protected $builder = '\\think\\db\\builder\\Mysql';
+
     /**
      * 解析pdo连接的dsn信息
      * @access protected
diff --git a/library/think/db/connector/Pgsql.php b/library/think/db/connector/Pgsql.php
index 4f8756ca..04c3e782 100644
--- a/library/think/db/connector/Pgsql.php
+++ b/library/think/db/connector/Pgsql.php
@@ -19,6 +19,7 @@ use think\db\Connection;
  */
 class Pgsql extends Connection
 {
+    protected $builder = '\\think\\db\\builder\\Pgsql';
 
     /**
      * 解析pdo连接的dsn信息
diff --git a/library/think/db/connector/Sqlite.php b/library/think/db/connector/Sqlite.php
index 4a08c740..a0e0873c 100644
--- a/library/think/db/connector/Sqlite.php
+++ b/library/think/db/connector/Sqlite.php
@@ -20,6 +20,8 @@ use think\db\Connection;
 class Sqlite extends Connection
 {
 
+    protected $builder = '\\think\\db\\builder\\Sqlite';
+
     /**
      * 解析pdo连接的dsn信息
      * @access protected
diff --git a/library/think/db/connector/Sqlsrv.php b/library/think/db/connector/Sqlsrv.php
index 18148051..20d3491d 100644
--- a/library/think/db/connector/Sqlsrv.php
+++ b/library/think/db/connector/Sqlsrv.php
@@ -25,7 +25,7 @@ class Sqlsrv extends Connection
         PDO::ATTR_ERRMODE           => PDO::ERRMODE_EXCEPTION,
         PDO::ATTR_STRINGIFY_FETCHES => false,
     ];
-
+    protected $builder = '\\think\\db\\builder\\Sqlsrv';
     /**
      * 解析pdo连接的dsn信息
      * @access protected