How to insert into date column based on other columns?

Question

Hi
I have four columns in a table called game named as
R_Day - Type - Number
R_Month - Type - Number
R_Year - Type - Number
R_Date - Type - Date
I have around 1000 records and i want to fill R_Date column based on the data in the R_Day,R_Month,R_Year.
How to write a query to fill the R_Date column based on other three columns.
Thanks
srinivas

Answer 1

select
to_date(R_Day||'-'||R_Month||'-'||R_Year,'DD-MM-YYYY')
dt from (select 23 R_Day,07 R_Month,2007 R_Year from
dual);
Hi,
Update <Table Name> set R_Date=select
to_date(R_Day||'-'||R_Month||'-'||R_Year,'DD-MM-YYYY')
from <Table Name>
Regds.
Nirmal
SQL>  select * from test;
     R_DAY    R_MONTH     R_YEAR R_DATE
         1          1       2007
        21         11       2007
SQL> update test
  2  set r_date = select to_date(R_Day||'-'||R_Month||'-'||R_Year,'DD-MM-YYYY')
  3  from test;
set r_date = select to_date(R_Day||'-'||R_Month||'-'||R_Year,'DD-MM-YYYY')
ERROR at line 2:
ORA-00936: missing expression
SQL> update test
  2  set r_date = to_date(r_day||'-'||r_month||'-'||r_year,'dd-mm-yyyy');
2 rows updated.
SQL> select * from test;
     R_DAY    R_MONTH     R_YEAR R_DATE
         1          1       2007 01-JAN-07
        21         11       2007 21-NOV-07
NB:Please test before posting..