mapping now supported single mapping and struct derive

engine.go

@@ -2,7 +2,7 @@ package xorm
 
 import (
 	"database/sql"
-	//"fmt"
+	"fmt"
 	"reflect"
 	"strconv"
 	"strings"
@@ -154,7 +154,7 @@ func (engine *Engine) MapType(t reflect.Type) *Table {
 
 		if ormTagStr != "" {
 			col = Column{FieldName: t.Field(i).Name, Nullable: true, IsPrimaryKey: false,
-				IsAutoIncrement: false}
+				IsAutoIncrement: false, MapType: TWOSIDES}
 			ormTagStr = strings.ToLower(ormTagStr)
 			tags := strings.Split(ormTagStr, " ")
 			// TODO:
@@ -162,9 +162,22 @@ func (engine *Engine) MapType(t reflect.Type) *Table {
 				if tags[0] == "-" {
 					continue
 				}
+				if (tags[0] == "extends") &&
+					(fieldType.Kind() == reflect.Struct) &&
+					t.Field(i).Anonymous {
+					parentTable := engine.MapType(fieldType)
+					for name, col := range parentTable.Columns {
+						col.FieldName = fmt.Sprintf("%v.%v", fieldType.Name(), col.FieldName)
+						table.Columns[name] = col
+					}
+				}
 				for j, key := range tags {
 					k := strings.ToLower(key)
 					switch {
+					case k == "<-":
+						col.MapType = ONLYFROMDB
+					case k == "->":
+						col.MapType = ONLYTODB
 					case k == "pk":
 						col.IsPrimaryKey = true
 						col.Nullable = false
@@ -230,7 +243,7 @@ func (engine *Engine) MapType(t reflect.Type) *Table {
 		} else {
 			sqlType := Type2SQLType(fieldType)
 			col = Column{engine.Mapper.Obj2Table(t.Field(i).Name), t.Field(i).Name, sqlType,
-				sqlType.DefaultLength, sqlType.DefaultLength2, true, "", false, false, false}
+				sqlType.DefaultLength, sqlType.DefaultLength2, true, "", false, false, false, TWOSIDES}
 
 			if col.Name == "id" {
 				col.IsPrimaryKey = true

examples/derive.go

@@ -0,0 +1,65 @@
+package main
+
+import (
+	"fmt"
+	_ "github.com/mattn/go-sqlite3"
+	"os"
+	. "xorm"
+)
+
+type User struct {
+	Id   int64
+	Name string
+}
+
+type LoginInfo struct {
+	Id     int64
+	IP     string
+	UserId int64
+}
+
+type LoginInfo1 struct {
+	LoginInfo `xorm:"extends"`
+	UserName  string
+}
+
+func main() {
+	f := "derive.db"
+	os.Remove(f)
+
+	Orm, err := NewEngine("sqlite3", f)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	Orm.ShowSQL = true
+	err = Orm.CreateTables(&User{}, &LoginInfo{})
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	_, err = Orm.Insert(&User{1, "xlw"}, &LoginInfo{1, "127.0.0.1", 1})
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	info := LoginInfo{}
+	_, err = Orm.Id(1).Get(&info)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	fmt.Println(info)
+
+	infos := make([]LoginInfo1, 0)
+	err = Orm.Sql(`select *, (select name from user where id = login_info.user_id) as user_name from 
+			 login_info limit 10`).Find(&infos)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	fmt.Println(infos)
+}

examples/singlemapping.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"fmt"
+	_ "github.com/mattn/go-sqlite3"
+	"os"
+	. "xorm"
+)
+
+type User struct {
+	Id   int64
+	Name string
+}
+
+type LoginInfo struct {
+	Id     int64
+	IP     string
+	UserId int64
+	// timestamp should be updated by database, so only allow get from db
+	TimeStamp string `xorm:"<-"`
+	// assume
+	Nonuse int `xorm:"->"`
+}
+
+func main() {
+	f := "singleMapping.db"
+	os.Remove(f)
+
+	Orm, err := NewEngine("sqlite3", f)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	Orm.ShowSQL = true
+	err = Orm.CreateTables(&User{}, &LoginInfo{})
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	_, err = Orm.Insert(&User{1, "xlw"}, &LoginInfo{1, "127.0.0.1", 1, "", 23})
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	info := LoginInfo{}
+	_, err = Orm.Id(1).Get(&info)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	fmt.Println(info)
+}

session.go

@@ -157,8 +157,21 @@ func (session *Session) scanMapIntoStruct(obj interface{}, objMap map[string][]b
 	table := session.Engine.Tables[Type(obj)]
 
 	for key, data := range objMap {
-		structField := dataStruct.FieldByName(table.Columns[key].FieldName)
-		if !structField.CanSet() {
+		fieldName := table.Columns[key].FieldName
+		fieldPath := strings.Split(fieldName, ".")
+		var structField reflect.Value
+		if len(fieldPath) > 2 {
+			fmt.Printf("xorm: Warning! Unsupported mutliderive %v\n", fieldName)
+			continue
+		} else if len(fieldPath) == 2 {
+			parentField := dataStruct.FieldByName(fieldPath[0])
+			if parentField.IsValid() {
+				structField = parentField.FieldByName(fieldPath[1])
+			}
+		} else {
+			structField = dataStruct.FieldByName(fieldName)
+		}
+		if !structField.IsValid() || !structField.CanSet() {
 			continue
 		}
 
@@ -618,6 +631,9 @@ func (session *Session) InsertMulti(rowsSlicePtr interface{}) (int64, error) {
 				if col.IsAutoIncrement && fieldValue.Int() == 0 {
 					continue
 				}
+				if col.MapType == ONLYFROMDB {
+					continue
+				}
 				if table, ok := session.Engine.Tables[fieldValue.Type()]; ok {
 					pkField := reflect.Indirect(fieldValue).FieldByName(table.PKColumn().FieldName)
 					fmt.Println(pkField.Interface())
@@ -636,6 +652,9 @@ func (session *Session) InsertMulti(rowsSlicePtr interface{}) (int64, error) {
 				if col.IsAutoIncrement && fieldValue.Int() == 0 {
 					continue
 				}
+				if col.MapType == ONLYFROMDB {
+					continue
+				}
 				if table, ok := session.Engine.Tables[fieldValue.Type()]; ok {
 					pkField := reflect.Indirect(fieldValue).FieldByName(table.PKColumn().FieldName)
 					args = append(args, pkField.Interface())
@@ -681,6 +700,9 @@ func (session *Session) InsertOne(bean interface{}) (int64, error) {
 		if col.IsAutoIncrement && fieldValue.Int() == 0 {
 			continue
 		}
+		if col.MapType == ONLYFROMDB {
+			continue
+		}
 		if fieldTable, ok := session.Engine.Tables[fieldValue.Type()]; ok {
 			if fieldTable.PrimaryKey != "" {
 				pkField := reflect.Indirect(fieldValue).FieldByName(fieldTable.PKColumn().FieldName)

statement.go

@@ -202,7 +202,9 @@ func (statement *Statement) selectColumnStr() string {
 	table := statement.RefTable
 	colNames := make([]string, 0)
 	for _, col := range table.Columns {
-		colNames = append(colNames, statement.TableName()+"."+col.Name)
+		if col.MapType != ONLYTODB {
+			colNames = append(colNames, statement.TableName()+"."+col.Name)
+		}
 	}
 	return strings.Join(colNames, ", ")
 }

table.go

@@ -64,6 +64,12 @@ func Type2SQLType(t reflect.Type) (st SQLType) {
 	return
 }
 
+const (
+	TWOSIDES = iota + 1
+	ONLYTODB
+	ONLYFROMDB
+)
+
 type Column struct {
 	Name            string
 	FieldName       string
@@ -75,6 +81,7 @@ type Column struct {
 	IsUnique        bool
 	IsPrimaryKey    bool
 	IsAutoIncrement bool
+	MapType         int
 }
 
 type Table struct {