improve gvar by changig gvar.Var from type struct to interface

database/gdb/gdb.go

@@ -173,7 +173,7 @@ type Link interface {
 
 type (
 	// Value is the field value type.
-	Value = *gvar.Var
+	Value = gvar.Var
 
 	// Record is the row record of the table.
 	Record map[string]Value

database/gdb/gdb_core.go

@@ -244,12 +244,12 @@ func (c *Core) GetScan(pointer interface{}, sql string, args ...interface{}) err
 func (c *Core) GetValue(sql string, args ...interface{}) (Value, error) {
 	one, err := c.DB.GetOne(sql, args...)
 	if err != nil {
-		return nil, err
+		return gvar.New(nil), err
 	}
 	for _, v := range one {
 		return v, nil
 	}
-	return nil, nil
+	return gvar.New(nil), nil
 }
 
 // GetCount queries and returns the count from database.

database/gdb/gdb_model_select.go

@@ -8,6 +8,7 @@ package gdb
 
 import (
 	"fmt"
+	"github.com/gogf/gf/container/gvar"
 	"github.com/gogf/gf/util/gconv"
 	"reflect"
 )
@@ -118,12 +119,12 @@ func (m *Model) Value(fieldsAndWhere ...interface{}) (Value, error) {
 	}
 	one, err := m.One()
 	if err != nil {
-		return nil, err
+		return gvar.New(nil), err
 	}
 	for _, v := range one {
 		return v, nil
 	}
-	return nil, nil
+	return gvar.New(nil), nil
 }
 
 // Array queries and returns data values as slice from database.

database/gredis/gredis.go

@@ -210,8 +210,8 @@ func (r *Redis) Do(command string, args ...interface{}) (interface{}, error) {
 	return conn.Do(command, args...)
 }
 
-// DoVar returns value from Do as *gvar.Var.
-func (r *Redis) DoVar(command string, args ...interface{}) (*gvar.Var, error) {
+// DoVar returns value from Do as gvar.Var.
+func (r *Redis) DoVar(command string, args ...interface{}) (gvar.Var, error) {
 	v, err := r.Do(command, args...)
 	if result, ok := v.([]byte); ok {
 		return gvar.New(gconv.UnsafeBytesToStr(result)), err

database/gredis/gredis_conn.go

@@ -44,13 +44,13 @@ func (c *Conn) Do(commandName string, args ...interface{}) (reply interface{}, e
 }
 
 // DoVar retrieves and returns the result from command as gvar.Var.
-func (c *Conn) DoVar(command string, args ...interface{}) (*gvar.Var, error) {
+func (c *Conn) DoVar(command string, args ...interface{}) (gvar.Var, error) {
 	v, err := c.Do(command, args...)
 	return gvar.New(v), err
 }
 
 // ReceiveVar receives a single reply as gvar.Var from the Redis server.
-func (c *Conn) ReceiveVar() (*gvar.Var, error) {
+func (c *Conn) ReceiveVar() (gvar.Var, error) {
 	v, err := c.Receive()
 	return gvar.New(v), err
 }

database/gredis/gredis_z_example_test.go

@@ -15,7 +15,7 @@ import (
 func Example_autoMarshalUnmarshalMap() {
 	var (
 		err    error
-		result *gvar.Var
+		result gvar.Var
 		key    = "user"
 		data   = g.Map{
 			"id":   10000,
@@ -40,7 +40,7 @@ func Example_autoMarshalUnmarshalStruct() {
 	}
 	var (
 		err    error
-		result *gvar.Var
+		result gvar.Var
 		key    = "user"
 		user   = &User{
 			Id:   10000,
@@ -71,7 +71,7 @@ func Example_autoMarshalUnmarshalStructSlice() {
 	}
 	var (
 		err    error
-		result *gvar.Var
+		result gvar.Var
 		key    = "user-slice"
 		users1 = []User{
 			{
@@ -104,7 +104,7 @@ func Example_autoMarshalUnmarshalStructSlice() {
 func Example_hashSet() {
 	var (
 		err    error
-		result *gvar.Var
+		result gvar.Var
 		key    = "user"
 	)
 	_, err = g.Redis().Do("HSET", key, "id", 10000)

database/gredis/gredis_z_unit_test.go

@@ -356,7 +356,7 @@ func Test_Auto_MarshalSlice(t *testing.T) {
 
 	gtest.C(t, func(t *gtest.T) {
 		var (
-			result *gvar.Var
+			result gvar.Var
 			key    = "user-slice"
 			users1 = []User{
 				{