improve Struct convertion for package gdb; improve IsNil function for package internal/empty

database/gdb/gdb_func.go

@@ -1,4 +1,4 @@
-// Copyright GoFrame Author(https://github.com/gogf/gf). All Rights Reserved.
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
 //
 // This Source Code Form is subject to the terms of the MIT License.
 // If a copy of the MIT was not distributed with this file,
@@ -48,9 +48,9 @@ type apiMapStrAny interface {
 }
 
 const (
-	ORM_TAG_FOR_STRUCT  = "orm"
-	ORM_TAG_FOR_UNIQUE  = "unique"
-	ORM_TAG_FOR_PRIMARY = "primary"
+	OrmTagForStruct  = "orm"
+	OrmTagForUnique  = "unique"
+	OrmTagForPrimary = "primary"
 )
 
 var (
@@ -58,7 +58,7 @@ var (
 	quoteWordReg = regexp.MustCompile(`^[a-zA-Z0-9\-_]+$`)
 
 	// Priority tags for struct converting for orm field mapping.
-	structTagPriority = append([]string{ORM_TAG_FOR_STRUCT}, gconv.StructTagPriority...)
+	structTagPriority = append([]string{OrmTagForStruct}, gconv.StructTagPriority...)
 )
 
 // ListItemValues retrieves and returns the elements of all item struct/map with key <key>.
@@ -315,14 +315,14 @@ func doQuoteString(s, charLeft, charRight string) string {
 // GetWhereConditionOfStruct returns the where condition sql and arguments by given struct pointer.
 // This function automatically retrieves primary or unique field and its attribute value as condition.
 func GetWhereConditionOfStruct(pointer interface{}) (where string, args []interface{}, err error) {
-	tagField, err := structs.TagFields(pointer, []string{ORM_TAG_FOR_STRUCT})
+	tagField, err := structs.TagFields(pointer, []string{OrmTagForStruct})
 	if err != nil {
 		return "", nil, err
 	}
 	array := ([]string)(nil)
 	for _, field := range tagField {
 		array = strings.Split(field.TagValue, ",")
-		if len(array) > 1 && gstr.InArray([]string{ORM_TAG_FOR_UNIQUE, ORM_TAG_FOR_PRIMARY}, array[1]) {
+		if len(array) > 1 && gstr.InArray([]string{OrmTagForUnique, OrmTagForPrimary}, array[1]) {
 			return array[0], []interface{}{field.Value()}, nil
 		}
 		if len(where) > 0 {
@@ -336,14 +336,14 @@ func GetWhereConditionOfStruct(pointer interface{}) (where string, args []interf
 
 // GetPrimaryKey retrieves and returns primary key field name from given struct.
 func GetPrimaryKey(pointer interface{}) (string, error) {
-	tagField, err := structs.TagFields(pointer, []string{ORM_TAG_FOR_STRUCT})
+	tagField, err := structs.TagFields(pointer, []string{OrmTagForStruct})
 	if err != nil {
 		return "", err
 	}
 	array := ([]string)(nil)
 	for _, field := range tagField {
 		array = strings.Split(field.TagValue, ",")
-		if len(array) > 1 && array[1] == ORM_TAG_FOR_PRIMARY {
+		if len(array) > 1 && array[1] == OrmTagForPrimary {
 			return array[0], nil
 		}
 	}
@@ -741,7 +741,7 @@ func FormatSqlWithArgs(sql string, args []interface{}) string {
 // convertMapToStruct maps the <data> to given struct.
 // Note that the given parameter <pointer> should be a pointer to s struct.
 func convertMapToStruct(data map[string]interface{}, pointer interface{}) error {
-	tagNameMap, err := structs.TagMapName(pointer, []string{ORM_TAG_FOR_STRUCT})
+	tagNameMap, err := structs.TagMapName(pointer, []string{OrmTagForStruct})
 	if err != nil {
 		return err
 	}

database/gdb/gdb_type_record.go

@@ -11,6 +11,7 @@ import (
 	"github.com/gogf/gf/container/gmap"
 	"github.com/gogf/gf/encoding/gparser"
 	"github.com/gogf/gf/errors/gerror"
+	"github.com/gogf/gf/internal/empty"
 	"github.com/gogf/gf/util/gconv"
 	"reflect"
 )
@@ -47,7 +48,7 @@ func (r Record) GMap() *gmap.StrAnyMap {
 // Note that it returns sql.ErrNoRows if <r> is empty.
 func (r Record) Struct(pointer interface{}) error {
 	// If the record is empty, it returns error.
-	if r.IsEmpty() {
+	if r.IsEmpty() && !empty.IsNil(pointer, true) {
 		return sql.ErrNoRows
 	}
 	// Special handling for parameter type: reflect.Value

database/gdb/gdb_z_mysql_model_test.go

@@ -981,6 +981,18 @@ func Test_Model_Struct(t *testing.T) {
 		err := db.Table(table).Where("id=-1").Struct(user)
 		t.Assert(err, sql.ErrNoRows)
 	})
+	gtest.C(t, func(t *gtest.T) {
+		type User struct {
+			Id         int
+			Passport   string
+			Password   string
+			NickName   string
+			CreateTime *gtime.Time
+		}
+		var user *User
+		err := db.Table(table).Where("id=-1").Struct(&user)
+		t.Assert(err, nil)
+	})
 }
 
 func Test_Model_Struct_CustomType(t *testing.T) {

database/gdb/gdb_z_mysql_struct_test.go

@@ -1,4 +1,4 @@
-// Copyright GoFrame Author(https://github.com/gogf/gf). All Rights Reserved.
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
 //
 // This Source Code Form is subject to the terms of the MIT License.
 // If a copy of the MIT was not distributed with this file,
@@ -262,7 +262,8 @@ func Test_Struct_Empty(t *testing.T) {
 		one, err := db.Table(table).Where("id=100").One()
 		t.Assert(err, nil)
 		var user *User
-		t.AssertNE(one.Struct(&user), nil)
+		t.Assert(one.Struct(&user), nil)
+		t.Assert(user, nil)
 	})
 
 	gtest.C(t, func(t *gtest.T) {

frame/g/g_func.go

@@ -52,9 +52,12 @@ func TryCatch(try func(), catch ...func(exception error)) {
 }
 
 // IsNil checks whether given <value> is nil.
+// Parameter <traceSource> is used for tracing to the source variable if given <value> is type
+// of a pinter that also points to a pointer. It returns nil if the source is nil when <traceSource>
+// is true.
 // Note that it might use reflect feature which affects performance a little bit.
-func IsNil(value interface{}) bool {
-	return empty.IsNil(value)
+func IsNil(value interface{}, traceSource ...bool) bool {
+	return empty.IsNil(value, traceSource...)
 }
 
 // IsEmpty checks whether given <value> empty.

internal/empty/empty.go

@@ -1,10 +1,10 @@
-// Copyright 2019 gf Author(https://github.com/gogf/gf). All Rights Reserved.
+// Copyright GoFrame gf Author(https://goframe.org). All Rights Reserved.
 //
 // This Source Code Form is subject to the terms of the MIT License.
 // If a copy of the MIT was not distributed with this file,
 // You can obtain one at https://github.com/gogf/gf.
 
-// Package empty provides functions for checking empty variables.
+// Package empty provides functions for checking empty/nil variables.
 package empty
 
 import (
@@ -152,8 +152,11 @@ func IsEmpty(value interface{}) bool {
 }
 
 // IsNil checks whether given <value> is nil.
+// Parameter <traceSource> is used for tracing to the source variable if given <value> is type
+// of a pinter that also points to a pointer. It returns nil if the source is nil when <traceSource>
+// is true.
 // Note that it might use reflect feature which affects performance a little bit.
-func IsNil(value interface{}) bool {
+func IsNil(value interface{}, traceSource ...bool) bool {
 	if value == nil {
 		return true
 	}
@@ -168,10 +171,24 @@ func IsNil(value interface{}) bool {
 		reflect.Map,
 		reflect.Slice,
 		reflect.Func,
-		reflect.Ptr,
 		reflect.Interface,
 		reflect.UnsafePointer:
-		return rv.IsNil()
+		return !rv.IsValid() || rv.IsNil()
+
+	case reflect.Ptr:
+		if len(traceSource) > 0 && traceSource[0] {
+			for rv.Kind() == reflect.Ptr {
+				rv = rv.Elem()
+			}
+			if !rv.IsValid() {
+				return true
+			}
+			if rv.Kind() == reflect.Ptr {
+				return rv.IsNil()
+			}
+		} else {
+			return !rv.IsValid() || rv.IsNil()
+		}
 	}
 	return false
 }

internal/empty/empty_test.go

@@ -1,4 +1,4 @@
-// Copyright 2019 gf Author(https://github.com/gogf/gf). All Rights Reserved.
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
 //
 // This Source Code Form is subject to the terms of the MIT License.
 // If a copy of the MIT was not distributed with this file,
@@ -108,3 +108,22 @@ func TestIsEmpty(t *testing.T) {
 		t.Assert(empty.IsEmpty(tmpF6), false)
 	})
 }
+
+func TestIsNil(t *testing.T) {
+	gtest.C(t, func(t *gtest.T) {
+		t.Assert(empty.IsNil(nil), true)
+	})
+	gtest.C(t, func(t *gtest.T) {
+		var i int
+		t.Assert(empty.IsNil(i), false)
+	})
+	gtest.C(t, func(t *gtest.T) {
+		var i *int
+		t.Assert(empty.IsNil(i), true)
+	})
+	gtest.C(t, func(t *gtest.T) {
+		var i *int
+		t.Assert(empty.IsNil(&i), false)
+		t.Assert(empty.IsNil(&i, true), true)
+	})
+}