it returns error when Scan to a none empty slice with empty Result for package gdb (#2858)

contrib/drivers/mssql/mssql_z_basic_test.go

@@ -8,6 +8,7 @@ package mssql_test
 
 import (
 	"context"
+	"database/sql"
 	"fmt"
 	"testing"
 	"time"
@@ -804,8 +805,7 @@ func Test_DB_ToJson(t *testing.T) {
 		t.Assert(users[0].CreateTime, resultJson.Get("0.CREATE_TIME").String())
 
 		result = nil
-		err = result.Structs(&users)
-		t.AssertNil(err)
+		t.Assert(result.Structs(&users), sql.ErrNoRows)
 	})
 
 	gtest.C(t, func(t *gtest.T) {

contrib/drivers/mysql/mysql_core_test.go

@@ -8,6 +8,7 @@ package mysql_test
 
 import (
 	"context"
+	"database/sql"
 	"fmt"
 	"testing"
 	"time"
@@ -892,8 +893,7 @@ func Test_DB_ToJson(t *testing.T) {
 		t.Assert(users[0].CreateTime, resultJson.Get("0.create_time").String())
 
 		result = nil
-		err = result.Structs(&users)
-		t.AssertNil(err)
+		t.Assert(result.Structs(&users), sql.ErrNoRows)
 	})
 
 	gtest.C(t, func(t *gtest.T) {

contrib/drivers/mysql/mysql_feature_model_struct_test.go

@@ -301,7 +301,7 @@ func Test_Structs_Empty(t *testing.T) {
 		all, err := db.Model(table).Where("id>100").All()
 		t.AssertNil(err)
 		users := make([]User, 10)
-		t.Assert(all.Structs(&users), nil)
+		t.Assert(all.Structs(&users), sql.ErrNoRows)
 	})
 	gtest.C(t, func(t *gtest.T) {
 		all, err := db.Model(table).Where("id>100").All()
@@ -320,7 +320,7 @@ func Test_Structs_Empty(t *testing.T) {
 		all, err := db.Model(table).Where("id>100").All()
 		t.AssertNil(err)
 		users := make([]*User, 10)
-		t.Assert(all.Structs(&users), nil)
+		t.Assert(all.Structs(&users), sql.ErrNoRows)
 	})
 	gtest.C(t, func(t *gtest.T) {
 		all, err := db.Model(table).Where("id>100").All()

contrib/drivers/mysql/mysql_model_test.go

@@ -4665,3 +4665,44 @@ func Test_Builder_OmitEmptyWhere(t *testing.T) {
 		t.Assert(count, int64(TableSize))
 	})
 }
+
+func Test_Scan_Nil_Result_Error(t *testing.T) {
+	table := createInitTable()
+	defer dropTable(table)
+
+	type S struct {
+		Id    int
+		Name  string
+		Age   int
+		Score int
+	}
+	gtest.C(t, func(t *gtest.T) {
+		var s *S
+		err := db.Model(table).Where("id", 1).Scan(&s)
+		t.AssertNil(err)
+		t.Assert(s.Id, 1)
+	})
+	gtest.C(t, func(t *gtest.T) {
+		var s *S
+		err := db.Model(table).Where("id", 100).Scan(&s)
+		t.AssertNil(err)
+		t.Assert(s, nil)
+	})
+	gtest.C(t, func(t *gtest.T) {
+		var s S
+		err := db.Model(table).Where("id", 100).Scan(&s)
+		t.Assert(err, sql.ErrNoRows)
+	})
+	gtest.C(t, func(t *gtest.T) {
+		var ss []*S
+		err := db.Model(table).Scan(&ss)
+		t.AssertNil(err)
+		t.Assert(len(ss), TableSize)
+	})
+	// If the result is empty, it returns error.
+	gtest.C(t, func(t *gtest.T) {
+		var ss = make([]*S, 10)
+		err := db.Model(table).WhereGT("id", 100).Scan(&ss)
+		t.Assert(err, sql.ErrNoRows)
+	})
+}

contrib/drivers/sqlite/sqlite_core_test.go

@@ -8,6 +8,7 @@ package sqlite_test
 
 import (
 	"context"
+	"database/sql"
 	"fmt"
 	"testing"
 	"time"
@@ -839,8 +840,7 @@ func Test_DB_ToJson(t *testing.T) {
 		t.Assert(users[0].CreateTime, resultJson.Get("0.create_time").String())
 
 		result = nil
-		err = result.Structs(&users)
-		t.AssertNil(err)
+		t.Assert(result.Structs(&users), sql.ErrNoRows)
 	})
 
 	gtest.C(t, func(t *gtest.T) {

contrib/drivers/sqlitecgo/sqlite_core_test.go

@@ -8,6 +8,7 @@ package sqlitecgo_test
 
 import (
 	"context"
+	"database/sql"
 	"fmt"
 	"testing"
 	"time"
@@ -839,8 +840,7 @@ func Test_DB_ToJson(t *testing.T) {
 		t.Assert(users[0].CreateTime, resultJson.Get("0.create_time").String())
 
 		result = nil
-		err = result.Structs(&users)
-		t.AssertNil(err)
+		t.Assert(result.Structs(&users), sql.ErrNoRows)
 	})
 
 	gtest.C(t, func(t *gtest.T) {

database/gdb/gdb_type_result.go

@@ -7,10 +7,12 @@
 package gdb
 
 import (
+	"database/sql"
 	"math"
 
 	"github.com/gogf/gf/v2/container/gvar"
 	"github.com/gogf/gf/v2/encoding/gjson"
+	"github.com/gogf/gf/v2/internal/empty"
 	"github.com/gogf/gf/v2/util/gconv"
 )
 
@@ -191,5 +193,12 @@ func (r Result) RecordKeyUint(key string) map[uint]Record {
 // Structs converts `r` to struct slice.
 // Note that the parameter `pointer` should be type of *[]struct/*[]*struct.
 func (r Result) Structs(pointer interface{}) (err error) {
+	// If the result is empty and the target pointer is not empty, it returns error.
+	if r.IsEmpty() {
+		if !empty.IsEmpty(pointer, true) {
+			return sql.ErrNoRows
+		}
+		return nil
+	}
 	return gconv.StructsTag(r, pointer, OrmTagForStruct)
 }

frame/g/g_func.go

@@ -80,7 +80,7 @@ func TryCatch(ctx context.Context, try func(ctx context.Context), catch ...func(
 
 // IsNil checks whether given `value` is nil.
 // Parameter `traceSource` is used for tracing to the source variable if given `value` is type
-// of pinter that also points to a pointer. It returns nil if the source is nil when `traceSource`
+// of pointer 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.
 func IsNil(value interface{}, traceSource ...bool) bool {
@@ -90,8 +90,12 @@ func IsNil(value interface{}, traceSource ...bool) bool {
 // IsEmpty checks whether given `value` empty.
 // It returns true if `value` is in: 0, nil, false, "", len(slice/map/chan) == 0.
 // Or else it returns true.
-func IsEmpty(value interface{}) bool {
-	return empty.IsEmpty(value)
+//
+// The parameter `traceSource` is used for tracing to the source variable if given `value` is type of pointer
+// that also points to a pointer. It returns true if the source is empty when `traceSource` is true.
+// Note that it might use reflect feature which affects performance a little.
+func IsEmpty(value interface{}, traceSource ...bool) bool {
+	return empty.IsEmpty(value, traceSource...)
 }
 
 // RequestFromCtx retrieves and returns the Request object from context.

frame/g/g_z_unit_test.go

@@ -1,3 +1,9 @@
+// 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,
+// You can obtain one at https://github.com/gogf/gf.
+
 package g_test
 
 import (

internal/empty/empty.go

@@ -37,7 +37,11 @@ type iTime interface {
 // IsEmpty checks whether given `value` empty.
 // It returns true if `value` is in: 0, nil, false, "", len(slice/map/chan) == 0,
 // or else it returns false.
-func IsEmpty(value interface{}) bool {
+//
+// The parameter `traceSource` is used for tracing to the source variable if given `value` is type of pointer
+// that also points to a pointer. It returns true if the source is empty when `traceSource` is true.
+// Note that it might use reflect feature which affects performance a little.
+func IsEmpty(value interface{}, traceSource ...bool) bool {
 	if value == nil {
 		return true
 	}
@@ -88,6 +92,11 @@ func IsEmpty(value interface{}) bool {
 		return len(result) == 0
 
 	default:
+		// Finally, using reflect.
+		var rv reflect.Value
+		if v, ok := value.(reflect.Value); ok {
+			rv = v
+		} else {
 			// =========================
 			// Common interfaces checks.
 			// =========================
@@ -115,11 +124,7 @@ func IsEmpty(value interface{}) bool {
 				}
 				return len(f.MapStrAny()) == 0
 			}
-		// Finally, using reflect.
-		var rv reflect.Value
-		if v, ok := value.(reflect.Value); ok {
-			rv = v
-		} else {
+
 			rv = reflect.ValueOf(value)
 		}
 
@@ -169,21 +174,27 @@ func IsEmpty(value interface{}) bool {
 			reflect.Array:
 			return rv.Len() == 0
 
+		case reflect.Ptr:
+			if len(traceSource) > 0 && traceSource[0] {
+				return IsEmpty(rv.Elem())
+			}
+			return rv.IsNil()
+
 		case
 			reflect.Func,
-			reflect.Ptr,
 			reflect.Interface,
 			reflect.UnsafePointer:
-			if rv.IsNil() {
+			return rv.IsNil()
+
+		case reflect.Invalid:
 			return true
 		}
 	}
-	}
 	return false
 }
 
 // IsNil checks whether given `value` is nil, especially for interface{} type value.
-// Parameter `traceSource` is used for tracing to the source variable if given `value` is type of pinter
+// Parameter `traceSource` is used for tracing to the source variable if given `value` is type of pointer
 // 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.
 func IsNil(value interface{}, traceSource ...bool) bool {

os/gfpool/gfpool_pool.go

@@ -62,7 +62,7 @@ func newFilePool(p *Pool, path string, flag int, perm os.FileMode, ttl time.Dura
 // File retrieves file item from the file pointer pool and returns it. It creates one if
 // the file pointer pool is empty.
 // Note that it should be closed when it will never be used. When it's closed, it is not
-// really closed the underlying file pointer but put back to the file pinter pool.
+// really closed the underlying file pointer but put back to the file pointer pool.
 func (p *Pool) File() (*File, error) {
 	if v, err := p.pool.Get(); err != nil {
 		return nil, err