Thread: Problem -Postgre sql

[It's PostgreSQL, Postgres, or pgsql. It's never "postgre"]

On Oct 11, 2005, at 16:20 , Vikas J wrote:

> Hi
> I want to know substitute function for sql server ISNULL() function  
> in postgre

I'm not quite sure what the ISNULL() function does in SQL Server, but  
it sounds like it might be similar to either COALESCE or the IS NULL  
expression.

These pages might help you:

COALESCE
http://www.postgresql.org/docs/8.0/interactive/functions- 
conditional.html#AEN12056

IS NULL
http://www.postgresql.org/docs/8.0/interactive/functions-comparison.html

Hope this helps.

Michael Glaesemann
grzm myrealbox com

On Tue, Oct 11, 2005 at 12:50:49PM +0530, Vikas J wrote:
> I want to know substitute function for sql server ISNULL() function in postgre

If you look in the index of the PostgreSQL documentation you'll
find an entry for ISNULL:

http://www.postgresql.org/docs/8.0/interactive/bookindex.html

If PostgreSQL's ISNULL doesn't do what you want then please explain
what you're trying to do.  Many people on these lists don't use SQL
Server so they don't know its ISNULL works.

(BTW, it's PostgreSQL or Postgres, not Postgre.)

-- 
Michael Fuhr

[Please do not email me directly. Please post to the list so others  
may help and benefit from the discussion.]

On Oct 19, 2005, at 14:30 , Vikas J wrote:

> IsNull in sql server has syntax like isnull(column,substitute)
> if "column" is null it shows value of "substitute". That can be  
> achieved
> with CASE clause in postrgre but I want alternate function.

If you look at the doc links I provided below, you will find that  
COALESCE does exactly this.

> Can you tell me how to write function like MAX() that will work  
> directly  on
> colmuns. I want to create my own function that will not need table  
> name as
> paramter.
> it shld work similarly to max() function in postgre.

[Again, it's PostgreSQL or Postgres. It is *not* spelled "postgre".]

In my experience, the max() aggregate function does not require table  
names as parameters and work on columns directly.
http://www.postgresql.org/docs/8.0/interactive/functions-aggregate.html

I suggest you take some time to look at the docs. They're quite  
extensive and helpful.
http://www.postgresql.org/docs/8.0/interactive/index.html


Michael Glaesemann
grzm myrealbox com


>> I'm not quite sure what the ISNULL() function does in SQL Server, but
>> it sounds like it might be similar to either COALESCE or the IS NULL
>> expression.
>>
>> These pages might help you:
>>
>> COALESCE
>> http://www.postgresql.org/docs/8.0/interactive/functions-
>> conditional.html#AEN12056
>>
>> IS NULL
>> http://www.postgresql.org/docs/8.0/interactive/functions- 
>> comparison.html

Correct me if I am wrong, but isn't COALESCE standard in this way?

Best Wishes,
Chris Travers
Metatron Technology Consulting

Michael Glaesemann wrote:

> [Please do not email me directly. Please post to the list so others  
> may help and benefit from the discussion.]
>
> On Oct 19, 2005, at 14:30 , Vikas J wrote:
>
>> IsNull in sql server has syntax like isnull(column,substitute)
>> if "column" is null it shows value of "substitute". That can be  
>> achieved
>> with CASE clause in postrgre but I want alternate function.
>
>
> If you look at the doc links I provided below, you will find that  
> COALESCE does exactly this.
>
>> Can you tell me how to write function like MAX() that will work  
>> directly  on
>> colmuns. I want to create my own function that will not need table  
>> name as
>> paramter.
>> it shld work similarly to max() function in postgre.
>
>
> [Again, it's PostgreSQL or Postgres. It is *not* spelled "postgre".]
>
> In my experience, the max() aggregate function does not require table  
> names as parameters and work on columns directly.
> http://www.postgresql.org/docs/8.0/interactive/functions-aggregate.html
>
> I suggest you take some time to look at the docs. They're quite  
> extensive and helpful.
> http://www.postgresql.org/docs/8.0/interactive/index.html
>
>
> Michael Glaesemann
> grzm myrealbox com
>
>
>>> I'm not quite sure what the ISNULL() function does in SQL Server, but
>>> it sounds like it might be similar to either COALESCE or the IS NULL
>>> expression.
>>>
>>> These pages might help you:
>>>
>>> COALESCE
>>> http://www.postgresql.org/docs/8.0/interactive/functions-
>>> conditional.html#AEN12056
>>>
>>> IS NULL
>>> http://www.postgresql.org/docs/8.0/interactive/functions- 
>>> comparison.html
>>
>
>
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