How to view column families in HBase tables?
To view column families in an HBase table, you can use either the HBase shell or the HBase Java API to execute queries.
In HBase shell, you can use the following command to view column families in a table:
describe 'table_name'
This command will list all column families in the table along with their corresponding information.
You can use the Java API of HBase to retrieve the list of column families in a table with the following code:
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Table;
import java.io.IOException;
public class HBaseColumnFamilies {
public static void main(String[] args) throws IOException {
org.apache.hadoop.conf.Configuration config = HBaseConfiguration.create();
try (Connection connection = ConnectionFactory.createConnection(config);
Table table = connection.getTable(TableName.valueOf("table_name"))) {
HColumnDescriptor[] columnFamilies = table.getTableDescriptor().getColumnFamilies();
for (HColumnDescriptor columnFamily : columnFamilies) {
System.out.println("Column Family: " + columnFamily.getNameAsString());
}
}
}
}
The code above will connect to HBase, retrieve the list of column families in the specified table, and print out the name of each column family.