Question

任何人都可以使用cassandra的hector api来帮助知道如何使用特定列值更新行。

，相当于

UPDATE table_name SET value =“”其中column_name = column_value;

Answer 1

Cassandra中的更新可能只能通过主键完成。

（更一般地说，我建议在https://github.com/datastax/java-driver使用本地CQL驱动程序而不是半过时的Hector。）

Answer 2

    StringSerializer ss = StringSerializer.get();
    String keyspaceName = "Test_Keyspace";
    Cluster cluster = HFactory.getOrCreateCluster("TestCluster", new CassandraHostConfigurator("localhost:9160"));
    Keyspace ksp = HFactory.createKeyspace(keyspaceName, cluster);

// UPDATE =============================

ColumnFamilyTemplate<String, String> template = new ThriftColumnFamilyTemplate<String, String>(ksp,"Standard1",ss,ss);

    ColumnFamilyUpdater<String, String> updater = template.createUpdater("jsmith");
    updater.setString("first", "Devid");

    ColumnFamilyUpdater<String, String> updater2 = template.createUpdater("ksmith");
    updater2.setString("first", "Kohli");
    updater2.setString("middle", "Virat");

    try {
        template.update(updater);
        template.update(updater2);

        RangeSlicesQuery<String, String, String> rangeSlicesQuery3 = HFactory.createRangeSlicesQuery(ksp,ss,ss,ss);
        rangeSlicesQuery3.setColumnFamily("Standard1");
        rangeSlicesQuery3.setKeys("jsmith", "ksmith");
        rangeSlicesQuery3.setRange("jsmith", null, false, 4);
        QueryResult<OrderedRows<String, String, String>> result6 = rangeSlicesQuery3.execute();
    //  System.out.println(result6.get());
    } catch (HectorException e) {
        // do something ...
        e.printStackTrace();
    }

使用hector api基于cassandra中的列值更新行

2 个答案: