java - 使用 DataStax 客户端将参数传递给 Cassandra CQL 查询

Question

我正在使用 datastax 作为连接到 cassandra 的客户端。我已经通过 Java 成功连接到 cassandra cluster/keyspace/column family。我正在尝试，通过 java 对 cassandra 列族进行一些查询。对我来说，它适用于像

这样的简单查询

ResultSet results = session.execute("select * from demodb.customer where id = 1");

现在我想从用户那里获取 id 参数并将其传递给 session.execute(); 语句。我该怎么办？

Answer 1

这是一个使用准备好的语句插入有关图像的数据的代码示例。

PreparedStatement statement = getSession().prepare(
                               "INSERT INTO pixelstore.image " +
                               "(image_name, " +
                               " upload_time, " + 
                               " upload_by, " + 
                               " file_type, " + 
                               " file_size" +
                               ") VALUES (?, ?, ?, ?, ?);"); 

// create the bound statement and initialise it with your prepared statement
BoundStatement boundStatement = new BoundStatement(statement);

session.execute( // this is where the query is executed
  boundStatement.bind( // here you are binding the 'boundStatement'
    "background", TimeUtil.getTimeUUID(),  "lyubent", "png", "130527"));

最近有两篇关于 planet cassandra 的博客文章演示了驱动程序可以做什么，它们包含代码示例，请查看:

1. Materialized View with Cassandra and DataStax Java Driver
2. Small Java Application using DataStax Java Driver and Cassandra 1.2 working