fix #74 [BREAKING CHANGE] Select#GroupBy and Select#OrderBy behavior change.

Previous, GroupBy and OrderBy only keep the columns in the last call. Now, all columns are kept.

Author: huandu

go.mod

@@ -1,6 +1,6 @@
 module github.com/huandu/go-sqlbuilder
 
-go 1.12
+go 1.13
 
 require (
 	github.com/huandu/go-assert v1.1.5

injection.go

@@ -15,11 +15,6 @@ type injection struct {
 
 type injectionMarker int
 
-type injectedSQL struct {
-	marker injectionMarker
-	sql    string
-}
-
 // newInjection creates a new injection.
 func newInjection() *injection {
 	return &injection{

select.go

@@ -153,14 +153,14 @@ func (sb *SelectBuilder) Having(andExpr ...string) *SelectBuilder {
 
 // GroupBy sets columns of GROUP BY in SELECT.
 func (sb *SelectBuilder) GroupBy(col ...string) *SelectBuilder {
-	sb.groupByCols = col
+	sb.groupByCols = append(sb.groupByCols, col...)
 	sb.marker = selectMarkerAfterGroupBy
 	return sb
 }
 
 // OrderBy sets columns of ORDER BY in SELECT.
 func (sb *SelectBuilder) OrderBy(col ...string) *SelectBuilder {
-	sb.orderByCols = col
+	sb.orderByCols = append(sb.orderByCols, col...)
 	sb.marker = selectMarkerAfterOrderBy
 	return sb
 }

struct_test.go

@@ -245,7 +245,6 @@ func (db testDB) Query(query string, args ...interface{}) (testRows, error) {
 }
 
 func (db testDB) Exec(query string, args ...interface{}) {
-	return
 }
 
 func (rows testRows) Close() error {