CODEWITHSUNDEEP
javacassandra
John Doee
John Doee

Reputation: 59

Cassandra Java request

I trying to execute a simple request in Java with Cassandra database but I don't understand my example it don't work :

public class Test {

    public static void main( String[] args )
    {
        Cluster cluster = Cluster.builder()
                          .addContactPoints("127.0.0.1")
                          .build();
        Session session = cluster.connect("test");

        ResultSet results = session.execute("SELECT * FROM datatest");
        for ( Row row : results ) {
            System.out.println(row.getString("name"));
        }
    }

}

When I execute my code I have this error :

[main] INFO com.datastax.driver.core.policies.DCAwareRoundRobinPolicy - Using data-center name 'datacenter1' for DCAwareRoundRobinPolicy (if this is incorrect, please provide the correct datacenter name with DCAwareRoundRobinPolicy constructor)
[main] INFO com.datastax.driver.core.Cluster - New Cassandra host /127.0.0.1:9042 added
Exception in thread "main" java.lang.IllegalArgumentException: name is not a column defined in this metadata
    at com.datastax.driver.core.ColumnDefinitions.getAllIdx(ColumnDefinitions.java:273)
    at com.datastax.driver.core.ColumnDefinitions.getFirstIdx(ColumnDefinitions.java:279)
    at com.datastax.driver.core.ArrayBackedRow.getIndexOf(ArrayBackedRow.java:69)
    at com.datastax.driver.core.AbstractGettableData.getString(AbstractGettableData.java:137)
    at fakemillions.Test.main(Test.java:23)

This is my database :

My database screenshot

Upvotes: 3

Views: 4662

Answers (3)

Pradeep Bihani
Pradeep Bihani

Reputation: 111

Try this work in my case

Cluster.Builder builder = Cluster.builder();
Cluster cluster=builder.withLoadBalancingPolicy(new TokenAwarePolicy(new DCAwareRoundRobinPolicy("us-east"))).addContactPoints("127.0.0.1").build();

Upvotes: 1

Roman Tumaykin
Roman Tumaykin

Reputation: 1931

When you create a table using thrift, which contains dynamic columns, and therefore did not give explicit column definitions, then CQL by default assign the following names: key, column1, value. In your case it will have column1 contain the value "name", value column will contain "TiTi", etc.

Think about it as this. The data is stored really as key-value pairs. CQL can't infer any column names from these key-value pairs, since there may be billions of different keys (column names) in the same row.

Here is a good guide to migrate thrift tables to cql: http://www.datastax.com/dev/blog/thrift-to-cql3

Upvotes: 2

Ruba
Ruba

Reputation: 494

It sounds like you haven't defined a column with the name "name" in the table datatest. I haven't used Datastax driver before, but as the documentation says the IllegalArgumentException is thrown if

name is not part of the ResultSet this row is part of, i.e. if !this.columns().names().contains(name)

It'd be better if you provided how you created the datatest table.

Upvotes: 3

Related Questions