Cols("*") error

when my code Cols("*")   it will Gen. Sql like
SELECT "*" FROM.   it is no work in postgresql.

statement.go

@@ -782,7 +782,15 @@ func (statement *Statement) Cols(columns ...string) *Statement {
 	for _, nc := range newColumns {
 		statement.columnMap[strings.ToLower(nc)] = true
 	}
+
+	// by hzm
+	if len(newColumns) == 1 {
+		statement.ColumnStr = newColumns
+
+	} else {
 		statement.ColumnStr = statement.Engine.Quote(strings.Join(newColumns, statement.Engine.Quote(", ")))
+	}
+
 	if strings.Contains(statement.ColumnStr, ".") {
 		statement.ColumnStr = strings.Replace(statement.ColumnStr, ".", statement.Engine.Quote("."), -1)
 	}