使用 DataStax 客户端将参数传递给 Cassandra CQL 查询 [英] Passing parameter to Cassandra CQL query using DataStax client

问题描述

我使用 datastax 作为连接到 cassandra 的客户端.我已经通过 Java 成功连接到 cassandra 集群/键空间/列族.我正在尝试，通过 java 对 cassandra 列族发出一些查询.对我来说，它适用于像

I am using datastax as a client for connecting to cassandra. I have successfully connected to cassandra cluster/keyspace/column families through Java. I am trying, firing some queries on cassandra column family thriugh java. For me it is working for simple queries like

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?

Now I want to take id parameter from user and pass it to session.execute(); statement. How should I go about it?

推荐答案

这里是使用准备好的语句插入有关图像的数据的代码示例.

Here is a code example of inserting data about an image using a prepared statements.

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"));

最近在 cassandra 星球上有两篇博客文章展示了驱动程序的功能，其中包含代码示例，请查看:

There have been two recent blog posts on planet cassandra with a demo of what the driver can do, they contain code examples so check them out:

1. 使用 Cassandra 和 DataStax Java 驱动程序的物化视图
2. 使用 DataStax Java 驱动程序的小型 Java 应用程序和 Cassandra 1.2 工作

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