how to get the list of all table of a key space in cassandra

Question

I am new to cassandra, I am currently using CassandraCSharpDriver in a dummy application. I want to get the list of all the tables a user has described in a given key space.

        Cluster cluster = Cluster.Builder().AddContactPoints("IPAddress").Build();
        Session session = cluster.Connect("MyKeySpace");

In this code I want to get the list of all the tables of MyKeySpace

Answer 1

I'll run through how I would prepare that list of tables with the DataStax Cassandra C# driver:

Connect to your cluster:

Cluster cluster = Cluster.Builder().AddContactPoints("IPAddress").Build();
Session session = cluster.Connect();

I'll create a List<String> and use a prepared statement (because that's just a good idea) to bind the name of your keyspace. My CQL statement is only selecting columnfamily_name, which should be what you need.

List<String> tableList = new List<String>();

String strCQL = "SELECT columnfamily_name "
    + "FROM system.schema_columnfamilies WHERE keyspace_name=? ";
PreparedStatement pStatement = _session.Prepare(strCQL);
BoundStatement boundStatement = new BoundStatement(pStatement);
boundStatement.Bind("MyKeySpace");

Now I'll execute the statement, iterate through the results, and add each table name to the List I created above.

RowSet results = session.Execute(boundStatement);

foreach (Row result in results.GetRows())
{
    tableName = result.GetValue<String>("columnfamily_name");
    tableList.Add(tableName);
}

Now you should have a list of tables that you can add to your UI.

Answer 2

You can run:

select * from system.schema_columnfamilies where keyspace_name='MyKeySpace';

It runs against the "system" keyspace.

Answer 3

1. Get column names:

   SELECT column_name FROM system.schema_columns WHERE keyspace_name = 'KeySpaceName' AND columnfamily_name = 'TableName';
   

2. Get column family names, i.e., table names:

   select columnfamily_name from system.schema_columnfamilies where keyspace_name='KeySpaceName';
   

Answer 4

There is the option to use cluster metadata as well to get a string listing of keyspaces like so

var cluster = Cluster.Builder().AddContactPoints("IPAddress").Build();
var keyspaces = cluster.Metadata.GetKeyspaces();
foreach (var keyspaceName in keyspaces)
{
   Console.WriteLine(keyspaceName);
}