}
	// for i, t := range tokens {
	// 	fmt.Printf("%d: %#v\n", i, t)
	// }
}

func TestParseSelectStatement(t *testing.T) {
	exp, err := ParseSelectStatement("select _3,_1,_2 as 'mytest'  from S3object")
	if err != nil {
		t.Fatalf("parse alias sql error: %v", err)
	}
	if exp.selectAST.Expression.Expressions[2].As != "mytest" {