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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Content before git sha 34fdeebefcbf183ed7f916f931aa0586fdaa1b40
* Copyright (c) 2016, The Gocql authors,
* provided under the BSD-3-Clause License.
* See the NOTICE file distributed with this work for additional information.
*/
package gocql_test
import (
"context"
"fmt"
"log"
gocql "github.com/gocql/gocql"
)
func Example() {
/* The example assumes the following CQL was used to setup the keyspace:
create keyspace example with replication = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 };
create table example.tweet(timeline text, id UUID, text text, PRIMARY KEY(id));
create index on example.tweet(timeline);
*/
cluster := gocql.NewCluster("localhost:9042")
cluster.Keyspace = "example"
cluster.Consistency = gocql.Quorum
// connect to the cluster
session, err := cluster.CreateSession()
if err != nil {
log.Fatal(err)
}
defer session.Close()
ctx := context.Background()
// insert a tweet
if err := session.Query(`INSERT INTO tweet (timeline, id, text) VALUES (?, ?, ?)`,
"me", gocql.TimeUUID(), "hello world").WithContext(ctx).Exec(); err != nil {
log.Fatal(err)
}
var id gocql.UUID
var text string
/* Search for a specific set of records whose 'timeline' column matches
* the value 'me'. The secondary index that we created earlier will be
* used for optimizing the search */
if err := session.Query(`SELECT id, text FROM tweet WHERE timeline = ? LIMIT 1`,
"me").WithContext(ctx).Consistency(gocql.One).Scan(&id, &text); err != nil {
log.Fatal(err)
}
fmt.Println("Tweet:", id, text)
fmt.Println()
// list all tweets
scanner := session.Query(`SELECT id, text FROM tweet WHERE timeline = ?`,
"me").WithContext(ctx).Iter().Scanner()
for scanner.Next() {
err = scanner.Scan(&id, &text)
if err != nil {
log.Fatal(err)
}
fmt.Println("Tweet:", id, text)
}
// scanner.Err() closes the iterator, so scanner nor iter should be used afterwards.
if err := scanner.Err(); err != nil {
log.Fatal(err)
}
// Tweet: cad53821-3731-11eb-971c-708bcdaada84 hello world
//
// Tweet: cad53821-3731-11eb-971c-708bcdaada84 hello world
// Tweet: d577ab85-3731-11eb-81eb-708bcdaada84 hello world
}
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