Altering Column Families
You can alter column families, including the default column family for a table, by
using the Admin.alterFamily()
method in the MapR Database JSON Java API library.
Permissions Required
Example
Here is an example of using the API to change the name of a column family:
public void alterColumnFamily(String tablePath, String familyName, String newFamilyName) throws DBException { try (Admin admin = MapRDB.newAdmin()) { /* Get a TableDescriptor object for the table. This object gives access to the column families that are in the table. */ TableDescriptor tableDesc = admin.getTableDescriptor(tablePath); /* Get a FamilyDescriptor object for the column family to change the name of. / FamilyDescriptor familyDesc = tableDesc.getFamily(familyName); // Rename the column family. familyDesc.setName(newFamilyName); /* Call alterFamily(), passing in the path of the table, the original name of the column family, and the FamilyDescriptor in which the new name was set. */ admin.alterFamily(tablePath, familyName, familyDesc); } }
Alternative Method
You can also edit column families in JSON tables by running the command table cf edit
.