Statements

To execute a query, you create a Statement instance and pass it to Session#execute(). The driver provides various implementations:

  • SimpleStatement: a simple implementation built directly from a character string. Typically used for queries that are executed only once or a few times.
  • BoundStatement: obtained by binding values to a prepared statement. Typically used for queries that are executed often, with different values.
  • BuiltStatement: a statement built with the QueryBuilder DSL. It can be executed directly like a simple statement, or prepared.
  • BatchStatement: a statement that groups multiple statements to be executed as a batch.

Session also has a shortcut to build and execute a simple statement in a single call:

session.execute("select release_version from system.local");

// Is equivalent to:
Statement s = new SimpleStatement("select release_version from system.local");
session.execute(s);

Customizing execution

Before executing a statement, you might want to customize certain aspects of its execution. Statement provides a number of methods for this, for example:

Statement s = new SimpleStatement("select release_version from system.local");
s.enableTracing();
session.execute(s);

If you use custom policies (RetryPolicy, LoadBalancingPolicy, SpeculativeExecutionPolicy…), you might also want to have custom properties that influence statement execution. To achieve this, you can wrap your statements in a custom StatementWrapper implementation.