Add ScanRows support

callbacks/query.go

@@ -105,7 +105,7 @@ func Query(db *gorm.DB) {
 	}
 	defer rows.Close()
 
-	Scan(rows, db)
+	gorm.Scan(rows, db, false)
 }
 
 func Preload(db *gorm.DB) {

finisher_api.go

@@ -186,8 +186,13 @@ func (db *DB) Scan(dest interface{}) (tx *DB) {
 	return
 }
 
-func (db *DB) ScanRows(rows *sql.Rows, result interface{}) error {
+func (db *DB) ScanRows(rows *sql.Rows, dest interface{}) error {
-	return nil
+	tx := db.getInstance()
+	tx.Error = tx.Statement.Parse(dest)
+	tx.Statement.Dest = dest
+	tx.Statement.ReflectValue = reflect.Indirect(reflect.ValueOf(dest))
+	Scan(rows, tx, true)
+	return tx.Error
 }
 
 // Transaction start a transaction as a block, return error will rollback, otherwise to commit.

scan.go

@@ -1,15 +1,14 @@
-package callbacks
+package gorm
 
 import (
 	"database/sql"
 	"reflect"
 	"strings"
 
-	"github.com/jinzhu/gorm"
 	"github.com/jinzhu/gorm/schema"
 )
 
-func Scan(rows *sql.Rows, db *gorm.DB) {
+func Scan(rows *sql.Rows, db *DB, initialized bool) {
 	columns, _ := rows.Columns()
 	values := make([]interface{}, len(columns))
 
@@ -19,7 +18,7 @@ func Scan(rows *sql.Rows, db *gorm.DB) {
 			values[idx] = new(interface{})
 		}
 
-		if rows.Next() {
+		if initialized || rows.Next() {
 			db.RowsAffected++
 			rows.Scan(values...)
 		}
@@ -39,7 +38,8 @@ func Scan(rows *sql.Rows, db *gorm.DB) {
 			values[idx] = new(interface{})
 		}
 
-		for rows.Next() {
+		for initialized || rows.Next() {
+			initialized = false
 			db.RowsAffected++
 			rows.Scan(values...)
 
@@ -50,7 +50,8 @@ func Scan(rows *sql.Rows, db *gorm.DB) {
 			*dest = append(*dest, v)
 		}
 	case *int, *int64, *uint, *uint64:
-		for rows.Next() {
+		for initialized || rows.Next() {
+			initialized = false
 			db.RowsAffected++
 			rows.Scan(dest)
 		}
@@ -78,7 +79,8 @@ func Scan(rows *sql.Rows, db *gorm.DB) {
 				}
 			}
 
-			for rows.Next() {
+			for initialized || rows.Next() {
+				initialized = false
 				elem := reflect.New(db.Statement.Schema.ModelType).Elem()
 				for idx, field := range fields {
 					if field != nil {
@@ -118,7 +120,7 @@ func Scan(rows *sql.Rows, db *gorm.DB) {
 				}
 			}
 
-			if rows.Next() {
+			if initialized || rows.Next() {
 				db.RowsAffected++
 				if err := rows.Scan(values...); err != nil {
 					db.AddError(err)
@@ -128,6 +130,6 @@ func Scan(rows *sql.Rows, db *gorm.DB) {
 	}
 
 	if db.RowsAffected == 0 && db.Statement.RaiseErrorOnNotFound {
-		db.AddError(gorm.ErrRecordNotFound)
+		db.AddError(ErrRecordNotFound)
 	}
 }

tests/scan_test.go

@@ -1,6 +1,9 @@
 package tests_test
 
 import (
+	"reflect"
+	"sort"
+	"strings"
 	"testing"
 
 	. "github.com/jinzhu/gorm/tests"
@@ -24,7 +27,7 @@ func TestScan(t *testing.T) {
 	}
 
 	var doubleAgeRes = &result{}
-	if err := DB.Debug().Table("users").Select("age + age as age").Where("id = ?", user3.ID).Scan(&doubleAgeRes).Error; err != nil {
+	if err := DB.Table("users").Select("age + age as age").Where("id = ?", user3.ID).Scan(&doubleAgeRes).Error; err != nil {
 		t.Errorf("Scan to pointer of pointer")
 	}
 
@@ -32,9 +35,44 @@ func TestScan(t *testing.T) {
 		t.Errorf("Scan double age as age, expect: %v, got %v", res.Age*2, doubleAgeRes.Age)
 	}
 
-	var ress []result
+	var results []result
-	DB.Table("users").Select("name, age").Where("id in ?", []uint{user2.ID, user3.ID}).Scan(&ress)
+	DB.Table("users").Select("name, age").Where("id in ?", []uint{user2.ID, user3.ID}).Scan(&results)
-	if len(ress) != 2 || ress[0].Name != user2.Name || ress[1].Name != user3.Name {
+
+	sort.Slice(results, func(i, j int) bool {
+		return strings.Compare(results[i].Name, results[j].Name) < -1
+	})
+
+	if len(results) != 2 || results[0].Name != user2.Name || results[1].Name != user3.Name {
 		t.Errorf("Scan into struct map")
 	}
 }
+
+func TestScanRows(t *testing.T) {
+	user1 := User{Name: "ScanRowsUser1", Age: 1}
+	user2 := User{Name: "ScanRowsUser2", Age: 10}
+	user3 := User{Name: "ScanRowsUser3", Age: 20}
+	DB.Save(&user1).Save(&user2).Save(&user3)
+
+	rows, err := DB.Table("users").Where("name = ? or name = ?", user2.Name, user3.Name).Select("name, age").Rows()
+	if err != nil {
+		t.Errorf("Not error should happen, got %v", err)
+	}
+
+	type Result struct {
+		Name string
+		Age  int
+	}
+
+	var results []Result
+	for rows.Next() {
+		var result Result
+		if err := DB.ScanRows(rows, &result); err != nil {
+			t.Errorf("should get no error, but got %v", err)
+		}
+		results = append(results, result)
+	}
+
+	if !reflect.DeepEqual(results, []Result{{Name: "ScanRowsUser2", Age: 10}, {Name: "ScanRowsUser3", Age: 20}}) {
+		t.Errorf("Should find expected results")
+	}
+}