code: private String getInClause(String[] fields) {
  		StringBuilder builder = new StringBuilder("( ");
  		if (fields.length != 0) {
  			for (int i = 0; i < fields.length; i++) {
  				builder.append("'");
  				builder.append(fields[i]);
  				builder.append("'");
  				if (i != fields.length - 1) {
  					builder.append(" , ");
  				}
  			}
  		}
  		builder.append(" )");
  		return builder.toString();
  	}
docs: Return a SQL IN set parameter with the specified array of string e.g.
  "( 'arg1' , 'arg2' , 'arg3' )"
  
  @param fields
  @return the IN clause