I'm trying to get the number of key value pairs in a Cassandra column family. Following is the code I used.
PreparedStatement statement = client.session
.prepare("select count(*) from corpus.word_usage");
ResultSet results = client.session.execute(statement.bind());
Row row = results.one();
System.out.println(row.getVarint(0));
But when I ran this code, I'm getting following exception.
Exception in thread "main" com.datastax.driver.core.exceptions.InvalidTypeException: Column count is of type bigint
at com.datastax.driver.core.ColumnDefinitions.checkType(ColumnDefinitions.java:291)
at com.datastax.driver.core.ArrayBackedRow.getVarint(ArrayBackedRow.java:185)
at SimpleClient.main(SimpleClient.java:57)
According to datastax documentation (http://www.datastax.com/drivers/java/2.0/com/datastax/driver/core/Row.html) getVarint should return a BigInteger. So why I am getting a exception here? What an I doing wrong?
You can get value as a long, instead.
I couldn't test it but could you try this:
PreparedStatement statement = client.session.prepare("select count(*) from corpus.word_usage");
ResultSet results = client.session.execute(statement.bind());
Row row = results.one();
long expected = row.getLong("count");