Drivers and Sample Code - Practical Cassandra - page 139

Disconnecting
To disconnect from the cluster, all you need to do is call Shutdown on the cluster
object. Listing 9.10 shows how to do this.
Listing 9.10 Using C# to Disconnect from a Cluster
public void Close() {
cluster.Shutdown();
}
Schema Creation
Now that all of the connections have been created, we can create our schema.
When creating the schema, we can use the optional IF NOT EXISTS condition-
al, which will allow running the command multiple times without error. When this
conditional is not specified, additional executions of the schema creation code will
result in a QueryExecutionException . This conditional is available only in
Cassandra 2.0 and later. Listing 9.11 shows how to create a keyspace and a sample
table.
Listing 9.11 Creating a Schema in C#
Click here to view code image
public void CreateSchema() {
session.Execute("CREATE KEYSPACE IF NOT EXISTS
portfolio_demo " +
"WITH REPLICATION = { 'class': 'Sim-
pleStrategy', " +
"'replication_factor': 1 };");
session.Execute("CREATE TABLE IF NOT EXISTS port-
folio_demo.portfolio (" +
"portfolio_id UUID, ticker TEXT, " +
"current_price DECIMAL, current_change
DECIMAL, " +
"current_change_percent FLOAT, " +
"PRIMARY KEY(portfolio_id, ticker));");
}