sql - oracle compare date to null -


i have query comparing date 1 table max date table. problem having when date null being compared against. take following query:

select col1 table1 date > (select max(date) table b);

the query works fine except when subquery returns 0 rows. in case of 0 rows want return rows. in other words want date compare datetime min value. in case of 0 rows want compare:

date > '01-01-1900'

i have tried using case statements no luck feel missing simple.

any appreciated

you want use nvl function assist. 

(nvl(p_datefield, to_date('01/01/1901','mm/dd/yyyy'))

so you:

select col1 table1 date > (select max(nvl(date, to_date('01/01/1901','mm/dd/yyyy')) table b);

the idea 01/01/1901 represents null. if don't it, change date can come grips on represent null on behalf.

update #1..a comment below suggests coalesce work better. could...so here's example:

select col1 table1 date > (select coalesce(date, to_date('01/01/1901','mm/dd/yyyy')) table b);

now have choice. enjoy.


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