code: private void addColumnToTable(TableInfo tableInfo, ColumnInfo column) throws Exception
      {
          CQLTranslator translator = new CQLTranslator();
          StringBuilder addColumnQuery = new StringBuilder("ALTER TABLE ");
          translator.ensureCase(addColumnQuery, tableInfo.getTableName(), false);
          addColumnQuery.append(" ADD ");
          translator.ensureCase(addColumnQuery, column.getColumnName(), false);
          addColumnQuery.append(" "
                  + translator.getCQLType(CassandraValidationClassMapper.getValidationClass(column.getType(),
                          isCql3Enabled(tableInfo))));
          try
          {
              KunderaCoreUtils.printQuery(addColumnQuery.toString(), showQuery);
              cassandra_client.execute_cql3_query(ByteBuffer.wrap(addColumnQuery.toString().getBytes()),
                      Compression.NONE, ConsistencyLevel.ONE);
          }
          catch (InvalidRequestException ireforAddColumn)
          {
              StringBuilder ireforAddColumnbBuilder = new StringBuilder("Invalid column name ");
              ireforAddColumnbBuilder.append(column.getColumnName() + " because it conflicts with an existing column");
              if (ireforAddColumn.getWhy() != null && ireforAddColumn.getWhy().equals(ireforAddColumnbBuilder.toString()))
              {
                  // alterColumnType(tableInfo, translator, column);
              }
              else
              {
                  log.error("Error occurred while altering column type of  table {}, Caused by: .",
                          tableInfo.getTableName(), ireforAddColumn);
                  throw new SchemaGenerationException("Error occurred while adding column into table "
                          + tableInfo.getTableName(), ireforAddColumn, "Cassandra", databaseName);
              }
          }
  
      }
docs: Adds column to table if not exists previously i.e. alter table.
  
  @param tableInfo
  the table info
  @param column
  the column
  @throws Exception
  the exception