diff --git a/library/think/db/builder/Mysql.php b/library/think/db/builder/Mysql.php
index 94f82b83..8eee746f 100644
--- a/library/think/db/builder/Mysql.php
+++ b/library/think/db/builder/Mysql.php
@@ -82,15 +82,18 @@ class Mysql extends Builder
     /**
      * 字段和表名处理
      * @access protected
-     * @param string $key
+     * @param mixed  $key
      * @param array  $options
      * @return string
      */
     protected function parseKey($key, $options = [], $strict = false)
     {
-        if (is_int($key)) {
+        if (is_numeric($key)) {
             return $key;
+        } elseif ($key instanceof Expression) {
+            return $key->getValue();
         }
+
         $key = trim($key);
         if (strpos($key, '$.') && false === strpos($key, '(')) {
             // JSON字段支持
diff --git a/library/think/db/builder/Pgsql.php b/library/think/db/builder/Pgsql.php
index 5885e721..acc22896 100644
--- a/library/think/db/builder/Pgsql.php
+++ b/library/think/db/builder/Pgsql.php
@@ -44,12 +44,18 @@ class Pgsql extends Builder
     /**
      * 字段和表名处理
      * @access protected
-     * @param string $key
+     * @param mixed  $key
      * @param array  $options
      * @return string
      */
     protected function parseKey($key, $options = [], $strict = false)
     {
+        if (is_numeric($key)) {
+            return $key;
+        } elseif ($key instanceof Expression) {
+            return $key->getValue();
+        }
+
         $key = trim($key);
         if (strpos($key, '$.') && false === strpos($key, '(')) {
             // JSON字段支持
diff --git a/library/think/db/builder/Sqlite.php b/library/think/db/builder/Sqlite.php
index fbd3bbaf..c727f04b 100644
--- a/library/think/db/builder/Sqlite.php
+++ b/library/think/db/builder/Sqlite.php
@@ -52,12 +52,18 @@ class Sqlite extends Builder
     /**
      * 字段和表名处理
      * @access protected
-     * @param string $key
+     * @param mixed  $key
      * @param array  $options
      * @return string
      */
     protected function parseKey($key, $options = [], $strict = false)
     {
+        if (is_numeric($key)) {
+            return $key;
+        } elseif ($key instanceof Expression) {
+            return $key->getValue();
+        }
+
         $key = trim($key);
         if (strpos($key, '.')) {
             list($table, $key) = explode('.', $key, 2);
diff --git a/library/think/db/builder/Sqlsrv.php b/library/think/db/builder/Sqlsrv.php
index e904827a..f79ae030 100644
--- a/library/think/db/builder/Sqlsrv.php
+++ b/library/think/db/builder/Sqlsrv.php
@@ -73,14 +73,16 @@ class Sqlsrv extends Builder
     /**
      * 字段和表名处理
      * @access protected
-     * @param string $key
+     * @param mixed  $key
      * @param array  $options
      * @return string
      */
     protected function parseKey($key, $options = [], $strict = false)
     {
-        if (is_int($key)) {
+        if (is_numeric($key)) {
             return $key;
+        } elseif ($key instanceof Expression) {
+            return $key->getValue();
         }
         $key = trim($key);
         if (strpos($key, '.') && !preg_match('/[,\'\"\(\)\[\s]/', $key)) {