code: public static void setInput(JobConf job, Class<? extends DBWritable> inputClass,
        String tableName,String conditions, String orderBy, String... fieldNames) {
      job.setInputFormat(DBInputFormat.class);
  
      DBConfiguration dbConf = new DBConfiguration(job);
      dbConf.setInputClass(inputClass);
      dbConf.setInputTableName(tableName);
      dbConf.setInputFieldNames(fieldNames);
      dbConf.setInputConditions(conditions);
      dbConf.setInputOrderBy(orderBy);
    }
docs: Initializes the map-part of the job with the appropriate input settings.
  
  @param job The job
  @param inputClass the class object implementing DBWritable, which is the
  Java object holding tuple fields.
  @param tableName The table to read data from
  @param conditions The condition which to select data with, eg. '(updated >
  20070101 AND length > 0)'
  @param orderBy the fieldNames in the orderBy clause.
  @param fieldNames The field names in the table
  @see #setInput(JobConf, Class, String, String)