Question

I am using grails/groovy, and from my controller I am currently doing this for retrieving field from Mysql table containing datetime field

SimpleDateFormat Sformat = new SimpleDateFormat("yyyy-MM-dd");
String format_datenow = Sformat.format(new Date());
String format_dateprevious = Sformat.format(new Date() -31);

 String markerCalcQuery =
            "select sum(trans_cnt) as t_cnt, location from map2_data where fdate between '"+format_dateprevious+"' and '"+format_dateprevious+"' and res_id = "+res_id+"  group by map2_data.location";
res_row=gurculsql.rows(markerCalcQuery);

The above query fails on Oracle11g with error

ORA-01843: not a valid month.

The error I feel is because MySQL stores date in this format: 2011-12-28 02:58:26 and Oracle stores date like this: 28-DEC-11 02.58.26.455000000 PM

How do I make the code generalised, one way is to make the database in Oracle store the date in the same format which I am thinking the way to handle this rather than from the code. If yes, how to change date format in the Oracle db?

Can I specify the format in the grails domain class for map2_data so that no matter what database it is we will have the datetime in the same format.

Answer 1

In Oracle, dates have their own type, they aren’t strings. If you have a string, you should convert it to a date using the TO_DATE function.

String format_datenow = "TO_DATE('" + Sformat.format(new Date()) + "', 'YYYY-MM-DD')";

To make it work also in MySQL, you can create a stored function named TO_DATE that just returns its first argument.