bug.go

package main

import (
	"bytes"
	"fmt"
	"github.com/gocql/gocql"
	"log"
	"reflect"
)

// Result of execution of a CQL statement
type CQLResult struct {
	status string
	rows   [][]string
}

func Print(result *CQLResult) {
	buf := new(bytes.Buffer)
	if result.status != "OK" {
		fmt.Fprintf(buf, "status: %s\n", result.status)
	} else if len(result.rows) != 0 {
		fmt.Fprintf(buf, "%v\n", result.rows)
	} else {
		fmt.Fprint(buf, "OK\n")
	}
	fmt.Print(string(buf.Bytes()))
}

func Execute(session *gocql.Session, cql string) {

	var result CQLResult

	query := session.Query(cql)
	err := query.Exec()

	if err == nil {
		result.status = "OK"

		iter := query.Iter()
		row, _ := iter.RowData()
		for {
			if !iter.Scan(row.Values...) {
				break
			}
			strrow := make([]string, len(row.Values))
			for i, v := range row.Values {
				strrow[i] = fmt.Sprint(reflect.Indirect(reflect.ValueOf(v)))
			}
			result.rows = append(result.rows, strrow)
		}
	} else {
		result.status = "ERROR"
	}
	Print(&result)
}

func main() {

	cluster := gocql.NewCluster("127.0.0.1")
	cluster.RetryPolicy = &gocql.SimpleRetryPolicy{NumRetries: 1}
	cluster.Authenticator = gocql.PasswordAuthenticator{Username: "cassandra", Password: ""}
	cluster.Keyspace = "test"
	session, err := cluster.CreateSession()
	if err != nil {
		log.Fatal(err)
	}
	statements := []string{
		"create table lwt (a int, listint list<int>, primary key (a))",
		"insert into lwt (a) values (1)",
		"update lwt set listint = listint + [5] where a = 1",
		"update lwt set listint = [-1] + listint where a = 1",
		"select * from lwt allow filtering",
	}
	for _, v := range statements {
		Execute(session, v)
	}
}