change Iterator struct naming to 'Rows' and making compatible interface to sql.Rows

base_test.go

@@ -1529,17 +1529,22 @@ func testIterate(engine *Engine, t *testing.T) {
 	}
 }
 
-func testScroll(engine *Engine, t *testing.T) {
-	iterator, err := engine.Omit("is_man").Scroll(new(Userinfo))
+func testRows(engine *Engine, t *testing.T) {
+	rows, err := engine.Omit("is_man").Rows(new(Userinfo))
 	if err != nil {
 		t.Error(err)
 		panic(err)
 	}
-	defer iterator.Close()
+	defer rows.Close()
 
 	idx := 0
-	for bean, err := iterator.Next(); err != nil; bean, err = iterator.NextReuse(bean) {
-		user := bean.(*Userinfo)
+	user := new(Userinfo)
+	for hasNext := rows.Next(); hasNext; hasNext = rows.Next() {
+		err = rows.Scan(user)
+		if err != nil {
+			t.Error(err)
+			panic(err)
+		}
 		fmt.Println(idx, "--", user)
 		idx++
 	}
@@ -3436,8 +3441,8 @@ func testAll2(engine *Engine, t *testing.T) {
 	testMetaInfo(engine, t)
 	fmt.Println("-------------- testIterate --------------")
 	testIterate(engine, t)
-	fmt.Println("-------------- testScroll --------------")
-	testScroll(engine, t)
+	fmt.Println("-------------- testRows --------------")
+	testRows(engine, t)
 	fmt.Println("-------------- testStrangeName --------------")
 	testStrangeName(engine, t)
 	fmt.Println("-------------- testVersion --------------")

engine.go

@@ -935,9 +935,9 @@ func (engine *Engine) Iterate(bean interface{}, fun IterFunc) error {
 
 // Similar to Iterate(), return a forward Iterator object for iterating record by record, bean's non-empty fields
 // are conditions.
-func (engine *Engine) Scroll(bean interface{}) (*Iterator, error) {
+func (engine *Engine) Rows(bean interface{}) (*Rows, error) {
 	session := engine.NewSession()
-	return session.Scroll(bean)
+	return session.Rows(bean)
 }
 
 // Count counts the records. bean's non-empty fields

iterator.go

@@ -1,99 +0,0 @@
-package xorm
-
-import (
-	"database/sql"
-	"reflect"
-)
-
-type Iterator struct {
-	session  *Session
-	stmt     *sql.Stmt
-	rows     *sql.Rows
-	fields   []string
-	beanType reflect.Type
-}
-
-func newIterator(session *Session, bean interface{}) (*Iterator, error) {
-	iterator := new(Iterator)
-	iterator.session = session
-	iterator.beanType = reflect.Indirect(reflect.ValueOf(bean)).Type()
-
-	err := iterator.session.newDb()
-	if err != nil {
-		return nil, err
-	}
-
-	defer iterator.session.Statement.Init()
-
-	var sql string
-	var args []interface{}
-	iterator.session.Statement.RefTable = iterator.session.Engine.autoMap(bean)
-	if iterator.session.Statement.RawSQL == "" {
-		sql, args = iterator.session.Statement.genGetSql(bean)
-	} else {
-		sql = iterator.session.Statement.RawSQL
-		args = iterator.session.Statement.RawParams
-	}
-
-	for _, filter := range iterator.session.Engine.Filters {
-		sql = filter.Do(sql, session)
-	}
-
-	iterator.session.Engine.LogSQL(sql)
-	iterator.session.Engine.LogSQL(args)
-
-	iterator.stmt, err = iterator.session.Db.Prepare(sql)
-	if err != nil {
-		defer iterator.Close()
-		return nil, err
-	}
-
-	iterator.rows, err = iterator.stmt.Query(args...)
-	if err != nil {
-		defer iterator.Close()
-		return nil, err
-	}
-
-	iterator.fields, err = iterator.rows.Columns()
-	if err != nil {
-		defer iterator.Close()
-		return nil, err
-	}
-
-	return iterator, nil
-}
-
-// iterate to next record and reuse passed bean obj
-func (iterator *Iterator) NextReuse(bean interface{}) (interface{}, error) {
-	if iterator.rows != nil && iterator.rows.Next() {
-		result, err := row2map(iterator.rows, iterator.fields) // !nashtsai! TODO remove row2map then scanMapIntoStruct conversation for better performance
-		if err == nil {
-			err = iterator.session.scanMapIntoStruct(bean, result)
-		}
-		if err == nil {
-			return bean, nil
-		} else {
-			return nil, err
-		}
-	}
-	return nil, sql.ErrNoRows
-}
-
-// iterate to next record
-func (iterator *Iterator) Next() (interface{}, error) {
-	b := reflect.New(iterator.beanType).Interface()
-	return iterator.NextReuse(b)
-}
-
-// close session if session.IsAutoClose is true, and claimed any opened resources
-func (iterator *Iterator) Close() {
-	if iterator.session.IsAutoClose {
-		defer iterator.session.Close()
-	}
-	if iterator.stmt != nil {
-		defer iterator.stmt.Close()
-	}
-	if iterator.rows != nil {
-		defer iterator.rows.Close()
-	}
-}

rows.go

@@ -0,0 +1,141 @@
+package xorm
+
+import (
+	"database/sql"
+	"fmt"
+	"reflect"
+)
+
+type Rows struct {
+	NoTypeCheck bool
+
+	session   *Session
+	stmt      *sql.Stmt
+	rows      *sql.Rows
+	fields    []string
+	beanType  reflect.Type
+	lastError error
+}
+
+func newRows(session *Session, bean interface{}) (*Rows, error) {
+	rows := new(Rows)
+	rows.session = session
+	rows.beanType = reflect.Indirect(reflect.ValueOf(bean)).Type()
+
+	err := rows.session.newDb()
+	if err != nil {
+		return nil, err
+	}
+
+	defer rows.session.Statement.Init()
+
+	var sql string
+	var args []interface{}
+	rows.session.Statement.RefTable = rows.session.Engine.autoMap(bean)
+	if rows.session.Statement.RawSQL == "" {
+		sql, args = rows.session.Statement.genGetSql(bean)
+	} else {
+		sql = rows.session.Statement.RawSQL
+		args = rows.session.Statement.RawParams
+	}
+
+	for _, filter := range rows.session.Engine.Filters {
+		sql = filter.Do(sql, session)
+	}
+
+	rows.session.Engine.LogSQL(sql)
+	rows.session.Engine.LogSQL(args)
+
+	rows.stmt, err = rows.session.Db.Prepare(sql)
+	if err != nil {
+		rows.lastError = err
+		defer rows.Close()
+		return nil, err
+	}
+
+	rows.rows, err = rows.stmt.Query(args...)
+	if err != nil {
+		rows.lastError = err
+		defer rows.Close()
+		return nil, err
+	}
+
+	rows.fields, err = rows.rows.Columns()
+	if err != nil {
+		rows.lastError = err
+		defer rows.Close()
+		return nil, err
+	}
+
+	return rows, nil
+}
+
+// move cursor to next record, return false if end has reached
+func (rows *Rows) Next() bool {
+	if rows.lastError == nil && rows.rows != nil {
+		hasNext := rows.rows.Next()
+		if !hasNext {
+			rows.lastError = sql.ErrNoRows
+		}
+		return hasNext
+	}
+	return false
+}
+
+// Err returns the error, if any, that was encountered during iteration. Err may be called after an explicit or implicit Close.
+func (rows *Rows) Err() error {
+	return rows.lastError
+}
+
+// scan row record to bean properties
+func (rows *Rows) Scan(bean interface{}) error {
+	if rows.lastError != nil {
+		return rows.lastError
+	}
+
+	if !rows.NoTypeCheck && reflect.Indirect(reflect.ValueOf(bean)).Type() != rows.beanType {
+		return fmt.Errorf("scan arg is incompatible type to [%v]", rows.beanType)
+	}
+
+	result, err := row2map(rows.rows, rows.fields) // !nashtsai! TODO remove row2map then scanMapIntoStruct conversation for better performance
+	if err == nil {
+		err = rows.session.scanMapIntoStruct(bean, result)
+	}
+	return err
+}
+
+// // Columns returns the column names. Columns returns an error if the rows are closed, or if the rows are from QueryRow and there was a deferred error.
+// func (rows *Rows) Columns() ([]string, error) {
+// 	if rows.lastError == nil && rows.rows != nil {
+// 		return rows.rows.Columns()
+// 	}
+// 	return nil, rows.lastError
+// }
+
+// close session if session.IsAutoClose is true, and claimed any opened resources
+func (rows *Rows) Close() error {
+	if rows.session.IsAutoClose {
+		defer rows.session.Close()
+	}
+
+	if rows.lastError == nil {
+		if rows.rows != nil {
+			rows.lastError = rows.rows.Close()
+			if rows.lastError != nil {
+				defer rows.stmt.Close()
+				return rows.lastError
+			}
+		}
+		if rows.stmt != nil {
+			rows.lastError = rows.stmt.Close()
+		}
+	} else {
+		if rows.stmt != nil {
+			defer rows.stmt.Close()
+		}
+		if rows.rows != nil {
+			defer rows.rows.Close()
+		}
+	}
+	return rows.lastError
+}

session.go

@@ -820,8 +820,8 @@ type IterFunc func(idx int, bean interface{}) error
 
 // Similar to Iterate(), return a forward Iterator object for iterating record by record, bean's non-empty fields
 // are conditions.
-func (session *Session) Scroll(bean interface{}) (*Iterator, error) {
-	return newIterator(session, bean)
+func (session *Session) Rows(bean interface{}) (*Rows, error) {
+	return newRows(session, bean)
 }
 
 // Iterate record by record handle records from table, condiBeans's non-empty fields
@@ -829,14 +829,19 @@ func (session *Session) Scroll(bean interface{}) (*Iterator, error) {
 // map[int64]*Struct
 func (session *Session) Iterate(bean interface{}, fun IterFunc) error {
 
-	iterator, err := session.Scroll(bean)
+	rows, err := session.Rows(bean)
 	if err != nil {
 		return err
 	} else {
-		defer iterator.Close()
+		defer rows.Close()
 		//b := reflect.New(iterator.beanType).Interface()
 		i := 0
-		for b, err := iterator.Next(); err != nil; b, err = iterator.Next() {
+		for hasNext := rows.Next(); hasNext; hasNext = rows.Next() {
+			b := reflect.New(rows.beanType).Interface()
+			err = rows.Scan(b)
+			if err != nil {
+				return err
+			}
 			err = fun(i, b)
 			if err != nil {
 				return err