diff --git a/gdb/sqldb/db.go b/gdb/sqldb/db.go
index c36378d..32fa4fc 100644
--- a/gdb/sqldb/db.go
+++ b/gdb/sqldb/db.go
@@ -21,7 +21,7 @@ import (
 	"time"
 )
 
-var DM *DbMap
+var dm *DbMap
 
 type DbOption struct {
 	Type               string
@@ -65,13 +65,24 @@ func InitDb(opt DbOption) error {
 	default:
 		return errors.New("unrecognized database driver")
 	}
-	DM = &DbMap{
+	dm = &DbMap{
 		Db:      db,
 		Dialect: dialect,
 	}
 	return nil
 }
 
+// 通过函数暴露句柄
+func GetDm() *DbMap {
+	if dm == nil {
+		InitDb(DbOption{
+			Type: "sqlite3",
+			Dsn:  ":memory:",
+		})
+	}
+	return dm
+}
+
 // DbMap is the root sqldb mapping object. Create one of these for each
 // database schema you wish to map.  Each DbMap contains a list of
 // mapped tables.