datetime - Concatenating DATE and TIME in SQL DEVELOPER -

i trying combine col_1, date ( dd/mm/yy 00:00:00) , col_2, time (hh24:mi:ss) 1 single column.

i researched few codes , tried couple (adddate(), to_date()), none of them work. know how combine these 2 columns when -->

a. col_1 date , col_2 time

b. col_1 date , col_2 char

date data types don't have specific format, can control format printing on column column basis to_char() function or can alter default display format entire session altering nls_date_format setting so:

alter session nls_date_format = 'dd/mm/yy hh24:mi:ss'; 

now if col_1 date column , col_2 string representation of time in hh24:mi:ss format, can convert col_2 interval data type , add col_1 so:

col_1 + cast('0 '||col_2 interval day second) 

when casting time string interval need leading '0 ' represent day portion of interval. in case 0 days.

if haven't changed nls_date_format string above, can output results in desired format so:

to_char(col_1 + cast('0 '||col_2 interval day second), 'dd/mm/yy hh24:mi:ss') 

however, it's best leave results in it's native date type later processing.