make pluck works

main.go

@@ -224,7 +224,7 @@ func (s *DB) Related(value interface{}, foreign_keys ...string) *DB {
 }
 
 func (s *DB) Pluck(column string, value interface{}) *DB {
-	return s.do(s.Value).pluck(column, value).db
+	return s.NewScope(s.Value).pluck(column, value).db
 }
 
 func (s *DB) Count(value interface{}) *DB {

scope.go

@@ -191,6 +191,10 @@ func (scope *Scope) TableName() string {
 	if len(scope.Search.tableName) > 0 {
 		return scope.Search.tableName
 	} else {
+		if scope.Value == nil {
+			scope.Err(errors.New("can't get table name"))
+			return ""
+		}
 		data := reflect.Indirect(reflect.ValueOf(scope.Value))
 
 		if data.Kind() == reflect.Slice {
@@ -380,22 +384,6 @@ func (scope *Scope) CommitOrRollback() *Scope {
 	return scope
 }
 
-func (scope *Scope) prepareQuerySql() {
-	if scope.Search.raw {
-		scope.Raw(strings.TrimLeft(scope.CombinedConditionSql(), "WHERE "))
-	} else {
-		scope.Raw(fmt.Sprintf("SELECT %v FROM %v %v", scope.selectSql(), scope.TableName(), scope.CombinedConditionSql()))
-	}
-	return
-}
-
-func (scope *Scope) inlineCondition(values []interface{}) *Scope {
-	if len(values) > 0 {
-		scope.Search = scope.Search.clone().where(values[0], values[1:]...)
-	}
-	return scope
-}
-
 func (scope *Scope) row() *sql.Row {
 	defer scope.Trace(time.Now())
 	scope.prepareQuerySql()
@@ -416,3 +404,23 @@ func (scope *Scope) initialize() *Scope {
 	scope.updatedAttrsWithValues(convertInterfaceToMap(scope.Search.assignAttrs), false)
 	return scope
 }
+
+func (scope *Scope) pluck(column string, value interface{}) *Scope {
+	dest := reflect.Indirect(reflect.ValueOf(value))
+	scope.Search = scope.Search.clone().selects(column)
+	if dest.Kind() != reflect.Slice {
+		scope.Err(errors.New("Results should be a slice"))
+		return scope
+	}
+
+	rows, err := scope.rows()
+	if scope.Err(err) == nil {
+		defer rows.Close()
+		for rows.Next() {
+			elem := reflect.New(dest.Type().Elem()).Interface()
+			scope.Err(rows.Scan(elem))
+			dest.Set(reflect.Append(dest, reflect.ValueOf(elem).Elem()))
+		}
+	}
+	return scope
+}

scope_condition.go

@@ -233,3 +233,19 @@ func (s *Scope) havingSql() string {
 func (s *Scope) joinsSql() string {
 	return s.Search.joinsStr + " "
 }
+
+func (scope *Scope) prepareQuerySql() {
+	if scope.Search.raw {
+		scope.Raw(strings.TrimLeft(scope.CombinedConditionSql(), "WHERE "))
+	} else {
+		scope.Raw(fmt.Sprintf("SELECT %v FROM %v %v", scope.selectSql(), scope.TableName(), scope.CombinedConditionSql()))
+	}
+	return
+}
+
+func (scope *Scope) inlineCondition(values []interface{}) *Scope {
+	if len(values) > 0 {
+		scope.Search = scope.Search.clone().where(values[0], values[1:]...)
+	}
+	return scope
+}