Query Mode

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Revision as of 18:31, 12 December 2010 by AW (talk | contribs) (→‎Example)
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In the query mode a query can be send to the server and executed in an iterative manner. For this you have to call the query() function of the Session with your defined query. This will return a query object which comes with an forward-only iterator to get each result of the query. Furthermore it is possible to bind variables to the query using the bind() function of the query object.

Usage

The query execution works as follows:

  1. Create a new session instance with hostname, port, username and password.
  2. Call the query() function of the session with the query as argument to get your query object.
  3. Optionally bind variables to the query with the bind() function.
  4. Initialize query output via init().
  5. Iterate through the query object with the more() and next() functions. If an error occurs, an exception is thrown.
  6. Close the query with close().

Example

  1. Create a session object: Session session = new Session("localhost", 1984, "admin", "admin");
  2. Define a query and create a query object:
    String q = "declare variable $name external; " "for $i in 1 to 10 return element { $name } { $i }";

Query query = session.query(q);

  1. Call the bind method of your query object:
    query.bind("$name", "Number");
  2. Call the init method of your query object:
    <
    print query.init();
  3. Iterate through the query object:
    while(query.more()) print query.next();
  4. Close your query object:
    print query.close();