diff --git a/base.php b/base.php
index db918e7f..a60c6988 100644
--- a/base.php
+++ b/base.php
@@ -13,7 +13,7 @@
 define('START_TIME', microtime(true));
 define('START_MEM', memory_get_usage());
 //  版本信息
-define('THINK_VERSION', '5.0.0 RC2');
+define('THINK_VERSION', '5.0.0 RC3');
 // 系统常量
 defined('DS') or define('DS', DIRECTORY_SEPARATOR);
 defined('THINK_PATH') or define('THINK_PATH', dirname(__FILE__) . DS);
diff --git a/library/think/Model.php b/library/think/Model.php
index bc390fd0..0b2bee0e 100644
--- a/library/think/Model.php
+++ b/library/think/Model.php
@@ -839,13 +839,18 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
                 $value = $this->$method($value, $this->data);
             } elseif (isset($this->type[$name])) {
                 // 类型转换
-                $type = $this->type[$name];
+                $type               = $this->type[$name];
+                list($type, $param) = explode(':', $type);
                 switch ($type) {
                     case 'integer':
                         $value = (int) $value;
                         break;
                     case 'float':
-                        $value = (float) $value;
+                        if (empty($param)) {
+                            $value = (float) $value;
+                        } else {
+                            $value = (float) number_format($value, $param);
+                        }
                         break;
                     case 'boolean':
                         $value = (bool) $value;
@@ -858,6 +863,7 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
                             $value = json_encode($value, JSON_FORCE_OBJECT);
                         }
                         break;
+                    case 'json':
                     case 'array':
                         if (is_array($value)) {
                             $value = json_encode($value, JSON_UNESCAPED_UNICODE);
@@ -891,20 +897,27 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
             return $this->$method($value, $this->data);
         } elseif (!is_null($value) && isset($this->type[$name])) {
             // 类型转换
-            $type = $this->type[$name];
+            $type               = $this->type[$name];
+            list($type, $param) = explode(':', $type);
             switch ($type) {
                 case 'integer':
                     $value = (int) $value;
                     break;
                 case 'float':
-                    $value = (float) $value;
+                    if (empty($param)) {
+                        $value = (float) $value;
+                    } else {
+                        $value = (float) number_format($value, $param);
+                    }
                     break;
                 case 'boolean':
                     $value = (bool) $value;
                     break;
                 case 'datetime':
-                    $value = date($this->dateFormat, $value);
+                    $format = $param ?: $this->dateFormat;
+                    $value  = date($format, $value);
                     break;
+                case 'json':
                 case 'array':
                     $value = json_decode($value, true);
                     break;
diff --git a/library/think/db/Builder.php b/library/think/db/Builder.php
index 905a6905..3d5be97a 100644
--- a/library/think/db/Builder.php
+++ b/library/think/db/Builder.php
@@ -89,7 +89,7 @@ abstract class Builder
         $result = [];
         foreach ($data as $key => $val) {
             if (!in_array($key, $fields, true)) {
-                if ($this->connection->getAttribute('fields_strict')) {
+                if ($this->connection->getConfig('fields_strict')) {
                     throw new Exception(' fields not exists :[' . $key . ']');
                 }
             } else {
@@ -106,7 +106,6 @@ abstract class Builder
                         $this->query->bind($key, $val, isset($bind[$key]) ? $bind[$key] : PDO::PARAM_STR);
                         $result[$item] = ':' . $key;
                     }
-
                 }
             }
         }
@@ -573,7 +572,7 @@ abstract class Builder
         foreach ($dataSet as &$data) {
             foreach ($data as $key => $val) {
                 if (!in_array($key, $fields, true)) {
-                    if ($this->connection->getAttribute('fields_strict')) {
+                    if ($this->connection->getConfig('fields_strict')) {
                         throw new Exception(' fields not exists :[' . $key . ']');
                     }
                     unset($data[$key]);
diff --git a/library/think/db/Connection.php b/library/think/db/Connection.php
index c16956e7..adfc1635 100644
--- a/library/think/db/Connection.php
+++ b/library/think/db/Connection.php
@@ -167,11 +167,23 @@ abstract class Connection
      * @param string $config 配置名称
      * @return mixed
      */
-    public function getAttribute($config)
+    public function getConfig($config)
     {
         return $this->config[$config];
     }
 
+    /**
+     * 设置数据库的配置参数
+     * @access public
+     * @param string $config 配置名称
+     * @param mixed $value 配置值
+     * @return void
+     */
+    public function setConfig($config, $value)
+    {
+        $this->config[$config] = $value;
+    }
+
     /**
      * 连接数据库方法
      * @access public
diff --git a/library/think/db/Query.php b/library/think/db/Query.php
index 7f6ca17c..6929d69b 100644
--- a/library/think/db/Query.php
+++ b/library/think/db/Query.php
@@ -336,7 +336,7 @@ class Query
                 }
             }
         } else {
-            $prefix = $this->connection->getAttribute('prefix');
+            $prefix = $this->connection->getConfig('prefix');
             // 传入的表名为数组
             if (is_array($join)) {
                 if (0 !== $key = key($join)) {