To filter data acording to year of date field of a table

Question

Hi i have a table
TABLE  T1(ID NUMBER, SET_DATE DATE)I want to select id values from this table by comparing year present in set_date field.
For that i wrote
select id from t1 where set_date like '%2010%' ;It's returning no rows.
But the following code is working
select id from t1 where set_date like '%10%' ;Though second code is working there is a demerit in both these code because i am not specifying to match year.It's quite possible that 10 may be present any where else, and this query will return all those rows.So how to filter rows according to year?

Answer 1

You should be careful that applying a function to your date column will bypass any indexes - unless it is an appropriate function based index. It is often better to convert your criteria to a match your data rather than convert your data once for every row in the table. The following example will allow the optimizer to use an index if appropriate;
with  t1 as(
   select 1 id, sysdate set_date from dual union all
   select 2, add_months(sysdate,-12) from dual)
select id
from t1
where set_date between to_date('01-jan-2010', 'dd-mon-yyyy') and
      to_date('31-dec-2010 23:59:59', 'dd-mon-yyyy hh24:mi:ss');
        ID
         1