add example code for gconv.Map; comment updates of gdb

g/database/gdb/gdb_mssql.go

@@ -11,6 +11,7 @@
     2.不支持save/replace方法
     3.不支持LastInsertId方法
 */
+
 package gdb
 
 import (

g/database/gdb/gdb_oracle.go

@@ -11,6 +11,7 @@
     2.不支持save/replace方法，可以调用这2个方法估计会报错，还没测试过,(应该是可以通过oracle的merge来实现这2个功能的，还没仔细研究)
     3.不支持LastInsertId方法
 */
+
 package gdb
 
 import (

g/database/gdb/gdb_structure.go

@@ -4,7 +4,6 @@
 // If a copy of the MIT was not distributed with this file,
 // You can obtain one at https://github.com/gogf/gf.
 
-
 package gdb
 
 import (

geg/util/gconv/gconv_map2.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+    "fmt"
+    "github.com/gogf/gf/g/util/gconv"
+)
+
+func main() {
+    type User struct {
+        Uid      int
+        Name     string `gconv:"-"`
+        NickName string `gconv:"nickname, omitempty"`
+        Pass1    string `gconv:"password1"`
+        Pass2    string `gconv:"password2"`
+    }
+    user := User{
+        Uid      : 100,
+        Name     : "john",
+        Pass1    : "123",
+        Pass2    : "456",
+    }
+    fmt.Println(gconv.Map(user))
+}