code: public static void setInput(JobConf job, Class<? extends DBWritable> inputClass,
        String inputQuery, String inputCountQuery) {
      job.setInputFormat(DBInputFormat.class);
      
      DBConfiguration dbConf = new DBConfiguration(job);
      dbConf.setInputClass(inputClass);
      dbConf.setInputQuery(inputQuery);
      dbConf.setInputCountQuery(inputCountQuery);
      
    }
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 inputQuery the input query to select fields. Example :
  "SELECT f1, f2, f3 FROM Mytable ORDER BY f1"
  @param inputCountQuery the input query that returns the number of records in
  the table.
  Example : "SELECT COUNT(f1) FROM Mytable"
  @see #setInput(JobConf, Class, String, String, String, String...)