Postgress problem 1

[Lee2]

Sorry to bother you with Postgress problem in ANSI-SQL
forum, but I didn't find any good postgress forum, so i hope someone here is able to help me.

I have problem with with NULLs.


My problem is as follows:
I have for example this table:

id | timestamps
---------------
1 | 9999343
---------------
2 |
---------------
3 | 9993434
--------------
4 |

where blank spaces are NULLs, and timestamps are unix timestamps.
Now I want to select value from my_table so that when the resulting row contains something, it will return 1 and when it is NULL the select will return 0

So I want this result:

1
_

0
_

1
_

0

I have tried almost everything but i CANNOT substitute NULLs
with 0 (or anything else, except NULL). It colud be done with the help of UNIONs but i am not allowed to use them, because after using UNION i cannot order the result.

Is postgress able to do any operation with NULLs?

for example: select col1 + 1 from table;

if the number in the col1 is a number, postgres will add 1 to that number. But if it is NULL it will return NULL, even if I explicitely cast NULL to type integer.

I have tried to apply many functions to critical column, but every function which i tried returned NULL instead anything else.

 

[fluteplr]

does postgres support a function called NVL or ISNULL the functions generally are in the format

nvl(myfield,0) which is a short cut for

return the value of myfield if it is not null otherwise return 0

or

does postgres support a case statement in a select
as in

select case myfield is null then 0 else 1 end as myvalue from mytable etc....

 

[Lee2]

thank you very much, it can be done with the case clausule.