Shavonne Marietta Wijesinghe wrote:
Hello
I have 2 records with the same value. Even when i do a select with
DISTINCT, it returns me both the records instead of one.
SELECT DISTINCT ON (TE_COGNOME) TE_COGNOME, TE_NOME, N_GEN_TEST,
TE_SESSO, TE_ATTNASC, TE_LUONASC, TE_INDI, TE_DTNASC, TE_PROVSTA
Aymeric Levaux <[EMAIL PROTECTED]> writes:
> SELECT DISTINCT tag FROM logs ORDER BY UPPER(tag);
> You get the following error message :
> for SELECT DISTINCT, ORDER BY expressions must appear in select list.
> It is weird as the order by column appears in the select.
No it doesn't. The ORDER BY
* Alvaro Herrera:
> Miroslav ?ulc wrote:
>> The GROUP BY is really fast :-)
>
> Doh! How does it do it?
It uses a hash table and can therefore discard duplicate rows more
quickly (essentially linear time in the number of rows if the number
of different rows is bounded).
Greg Stark napsal(a):
Actually you could try the equivalent query:
SELECT Key FROM MRTPContactValue GROUP BY Key
This may or may not be faster because it can use a hash aggregate plan. I
would expect it to be faster here because there are few distinct keys and the
planner predicts that.
Alvaro Herrera <[EMAIL PROTECTED]> writes:
> Miroslav ?ulc wrote:
> > Well, "key" is not primary key from another table. It is just a column
> > in pair "key" => "value".
> > The structure of the table is this:
> >
> > Id (primary key)
> > MRTPContactId (id of contact from table MRTPContact)
> >
Miroslav ?ulc wrote:
> The GROUP BY is really fast :-)
Doh! How does it do it?
--
Alvaro Herrerahttp://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.
---(end of broadcast)---
TIP 1: if posting
The GROUP BY is really fast :-)
Thank you.
Miroslav Šulc
Tom Lane napsal(a):
> Try
> SELECT Key FROM MRTPContactValue GROUP BY Key
>
> The "select distinct" code is a bit old and crufty, GROUP BY is usually
> smarter.
>
> regards, tom lane
>
begin:vcard
fn;quoted-
=?ISO-8859-2?Q?Miroslav_=A9ulc?= <[EMAIL PROTECTED]> writes:
> I have a table with cca 400,000 rows. The table contains column "key" of
> varchar(20) type containing 10 distinct values. I want to get out what
> distinct values are present in the column. I use this simple query,
> which is very slow
It might be a good solution :-)
Thank you for your help.
Miroslav Šulc
Alvaro Herrera napsal(a):
> Miroslav ?ulc wrote:
>
>> Well, "key" is not primary key from another table. It is just a column
>> in pair "key" => "value".
>> The structure of the table is this:
>>
>> Id (primary key)
>> MR
Miroslav ?ulc wrote:
> Well, "key" is not primary key from another table. It is just a column
> in pair "key" => "value".
> The structure of the table is this:
>
> Id (primary key)
> MRTPContactId (id of contact from table MRTPContact)
> Key (key from pair key => value)
> Value (value from pair ke
Well, "key" is not primary key from another table. It is just a column
in pair "key" => "value".
The structure of the table is this:
Id (primary key)
MRTPContactId (id of contact from table MRTPContact)
Key (key from pair key => value)
Value (value from pair key => value)
So I want the get th
Miroslav ?ulc wrote:
> Hello,
>
> I have a table with cca 400,000 rows. The table contains column "key" of
> varchar(20) type containing 10 distinct values. I want to get out what
> distinct values are present in the column. I use this simple query,
> which is very slow:
>
> SELECT DISTINCT Key F
he help,
Stijn Vanroye
-Original Message-
From: Viorel Dragomir [mailto:[EMAIL PROTECTED]
Sent: woensdag 28 april 2004 11:54
To: Stijn Vanroye; [EMAIL PROTECTED]
Subject: Re: [SQL] select distinct and order by
I don't know if this will work, but why not try it ? :)
select distinc
I don't know if this will work, but why not try it
? :)
select distinct fullname, distinct staff_id, loginname from staffwhere
staff_id in (select staff_id from staffmembership where
staffgroup_id=#SomeIdValue#)order by fullname, staff_id
Next one is more complicate but with more chan
Carlos <[EMAIL PROTECTED]> writes:
> Select distinct field1, field2 from table1 order by field3;
> The value return by PQresultErrorMessage is:
> For SELECT DISTINCT, ORDER BY expressions must appear in target list
> Whatever this query works fine in postgresql 6.5.3.
> Is correct this query a
On Wed, 11 Jul 2001, Carlos wrote:
> Select distinct field1, field2 from table1 order by field3;
>
> The value return by PQresultErrorMessage is:
>
> For SELECT DISTINCT, ORDER BY expressions must appear in target list
That's because this query is ambiguous.
What if table1 looks like this:
fie
From: "SCAHILL KEVIN" <[EMAIL PROTECTED]>
> I would like to pull each distinct value of LecturerName with any one
> corresponding ProjectCode value, it does not matter what the ProjectCode
> value is, but all attemps at this have failed so far.
>
> I have tried this but it does not work:
>
> Set
SCAHILL KEVIN <[EMAIL PROTECTED]> writes:
> I have tried this but it does not work:
> Set rsLecturers = Server.CreateObject("ADODB.Recordset")
> sqlLect = "Select LecturerName, MIN(ProjectCode) from tblSuggestions WHERE
> LecturerName IN ( SELECT DISTINCT LecturerName FROM tblSuggestions)"
> rsL
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