Re: LIMIT modifier

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Re: LIMIT modifier

От:
Arjen van der Meijden <acmmailing@vulcanus.its.tudelft.nl>
Дата:
Rod,

Have a look at the bottom of this page:
http://www.postgresql.org/docs/current/static/sql-select.html

"Nonstandard Clauses

The clauses DISTINCT ON, LIMIT, and OFFSET are not defined in the SQL 
standard."

TOP x isn't in the standard as well, afaik.

Best regards,

Arjen

Roderick A. Anderson wrote:

> I'm dealing with a project that requires me to query a MS SQL Server.  Not 
> a PostgreSQL issue I know but I want to ask if the LIMIT modifier is SQL 
> standard?  MS SQL Server uses a TOP modifier.
> 
> 	select top 1 * from xxx;
> 
> Whereas all the SQL RDBMS' I've used before used
> 
> 	select * from xxx limit 1;
> 
> Any enlightenment is appreciated. (I'm putting notes in the code to 
> reflect the non-standard stuff I've had to deal with.)
> 
> 
> TIA,
> Rod

Re: LIMIT modifier

От:
Troels Arvin <troels@arvin.dk>
Дата:
On Mon, 15 Dec 2003 09:32:34 -0800, Roderick A. Anderson wrote:

> want to ask if the LIMIT modifier is SQL standard?

No. The standard has no such thing:
http://troels.arvin.dk/db/rdbms/#select-limit

-- 
Greetings from Troels Arvin, Copenhagen, Denmark

Re: LIMIT modifier

От:
Troels Arvin <troels@arvin.dk>
Дата:
On Mon, 15 Dec 2003 09:32:34 -0800, Roderick A. Anderson wrote:

> want to ask if the LIMIT modifier is SQL standard?

No. The standard doesn't have anything like that, unfortunately.

> MS SQL Server uses a TOP modifier.

Yes, but it accepts an optional "WITH TIES" modifier which PostgreSQL
doesn't have.

See also:
http://troels.arvin.dk/db/rdbms/#select-limit

-- 
Greetings from Troels Arvin, Copenhagen, Denmark

LIMIT modifier

От:
"Roderick A. Anderson" <raanders@acm.org>
Дата:
I'm dealing with a project that requires me to query a MS SQL Server.  Not 
a PostgreSQL issue I know but I want to ask if the LIMIT modifier is SQL 
standard?  MS SQL Server uses a TOP modifier.

	select top 1 * from xxx;

Whereas all the SQL RDBMS' I've used before used

	select * from xxx limit 1;

Any enlightenment is appreciated. (I'm putting notes in the code to 
reflect the non-standard stuff I've had to deal with.)


TIA,
Rod
-- 
    "Open Source Software - You usually get more than you pay for..."
     "Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL"

Re: LIMIT modifier

От:
"Roderick A. Anderson" <raanders@acm.org>
Дата:
On Mon, 15 Dec 2003, Arjen van der Meijden wrote:

> "Nonstandard Clauses
> 
> The clauses DISTINCT ON, LIMIT, and OFFSET are not defined in the SQL 
> standard."

Humm.  Is there a SQL standard to return a subset of the selected tuples?  
This being contrary to relational theory I believe.  :-)

> TOP x isn't in the standard as well, afaik.

I had no doubts there.


Thanks,
Rod
-- 
    "Open Source Software - You usually get more than you pay for..."
     "Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL"
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