diff --git a/library/think/Model.php b/library/think/Model.php
index ddeeb95e..450675dc 100644
--- a/library/think/Model.php
+++ b/library/think/Model.php
@@ -257,11 +257,11 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
                     list($type, $param) = explode(':', $type, 2);
                 }
                 switch ($type) {
-                    case 'timestamp':
+                    case 'datetime':
                         $format = !empty($param) ? $param : $this->dateFormat;
                         $value  = date($format, $_SERVER['REQUEST_TIME']);
                         break;
-                    case 'datetime':
+                    case 'timestamp':
                         $value = $_SERVER['REQUEST_TIME'];
                         break;
                 }
diff --git a/library/think/db/Connection.php b/library/think/db/Connection.php
index 73669031..bfdafe6c 100644
--- a/library/think/db/Connection.php
+++ b/library/think/db/Connection.php
@@ -16,11 +16,11 @@ use PDOStatement;
 use think\App;
 use think\Collection;
 use think\Db;
+use think\db\exception\BindParamException;
 use think\db\Query;
 use think\Debug;
 use think\Exception;
 use think\exception\PDOException;
-use think\db\exception\BindParamException;
 use think\Log;
 
 abstract class Connection
@@ -102,7 +102,7 @@ abstract class Connection
 
     // PDO连接参数
     protected $params = [
-        PDO::ATTR_CASE              => PDO::CASE_LOWER,
+        PDO::ATTR_CASE              => PDO::CASE_NATURAL,
         PDO::ATTR_ERRMODE           => PDO::ERRMODE_EXCEPTION,
         PDO::ATTR_ORACLE_NULLS      => PDO::NULL_NATURAL,
         PDO::ATTR_STRINGIFY_FETCHES => false,
@@ -188,7 +188,7 @@ abstract class Connection
      * @param array $info 字段信息
      * @return array
      */
-    protected function fieldCase($info)
+    public function fieldCase($info)
     {
         // 字段大小写转换
         switch ($this->attrCase) {
@@ -330,7 +330,7 @@ abstract class Connection
         }
         // 根据参数绑定组装最终的SQL语句
         $this->queryStr = $this->getRealSql($sql, $bind);
-        
+
         //释放前次的查询结果
         if (!empty($this->PDOStatement)) {
             $this->free();
@@ -482,7 +482,7 @@ abstract class Connection
         if (!empty($class)) {
             // 返回指定数据集对象类
             $result = new $class($result);
-        } elseif ('collection' == $this->resultSetType){
+        } elseif ('collection' == $this->resultSetType) {
             // 返回数据集Collection对象
             $result = new Collection($result);
         }
@@ -551,7 +551,7 @@ abstract class Connection
 
         ++$this->transTimes;
 
-        if ($this->transTimes == 1) {
+        if (1 == $this->transTimes) {
             $this->linkID->beginTransaction();
         } elseif ($this->transTimes > 1 && $this->supportSavepoint()) {
             $this->linkID->exec(
@@ -570,7 +570,7 @@ abstract class Connection
     {
         $this->initConnect(true);
 
-        if ($this->transTimes == 1) {
+        if (1 == $this->transTimes) {
             $this->linkID->commit();
         }
 
@@ -587,7 +587,7 @@ abstract class Connection
     {
         $this->initConnect(true);
 
-        if ($this->transTimes == 1) {
+        if (1 == $this->transTimes) {
             $this->linkID->rollBack();
         } elseif ($this->transTimes > 1 && $this->supportSavepoint()) {
             $this->linkID->exec(