right...
- Original Message -
From: "Gabriel PREDA" <[EMAIL PROTECTED]>
To: "Ferindo Middleton" <[EMAIL PROTECTED]>
Cc: "Dan Buettner" <[EMAIL PROTECTED]>;
Sent: Friday, October 06, 2006 6:31 PM
Subject: Re: multiple primary keys on one
You will have to UPDATE to NULL those fields, modify the aplication to
enter NULL instead of empty-string... Then add the UNIQUE INDEX...
In MySQL (unless modified) the dafault is that NULL values are
incomparable thus allowing the creation of a UNIQUE INDEX.
-- -- -- -- -- -- -- -- -- -- -- --
> I have a primary key set on a table which consists of the combination of
the
> values: firstname, lastname, and a schedule_id (BIGINT(20))... I have this
> so the records in this table do not have duplicates, being that no one
> record should have the exact same name and schedule_id identifier.
Thanks. I now have this issue where I can't create the unique index on this
table because the email_address is often times blank or unknown for a while
(The front-end_application sets is value to '' (blank) on inserts and
updates if the user doesn't enter it so instead of going in as NULL, the
fie
At 06:26 PM 10/5/2006, Ferindo Middleton wrote:
I have a primary key set on a table which consists of the combination of the
values: firstname, lastname, and a schedule_id (BIGINT(20))... I have this
so the records in this table do not have duplicates, being that no one
record should have the ex
Ferindo, you can create multiple UNIQUE indexes on a table to enforce
your data requirements.
http://dev.mysql.com/doc/refman/5.0/en/alter-table.html
Dan
On 10/5/06, Ferindo Middleton <[EMAIL PROTECTED]> wrote:
I have a primary key set on a table which consists of the combination of the
values:
I have a primary key set on a table which consists of the combination of the
values: firstname, lastname, and a schedule_id (BIGINT(20))... I have this
so the records in this table do not have duplicates, being that no one
record should have the exact same name and schedule_id identifier.
However
AIL PROTECTED]>
To: "'Kishore Jalleda'" <[EMAIL PROTECTED]>
Cc:
Sent: Thursday, April 27, 2006 9:11 AM
Subject: RE: Multiple primary keys
Thanks all. The query I run is a subquery.
I noticed joined query run a lot faster than the sub.
This is the sub
218 classC: 357
So not having a primary key/index will slow my queries?
-Original Message-
From: Kishore Jalleda [mailto:[EMAIL PROTECTED]
Sent: Thursday, April 27, 2006 10:49 AM
To: nngau
Cc: mysql@lists.mysql.com
Subject: Re: Multiple primary keys
On 4/27/06, nngau <[EMAIL PROT
On 4/27/06, nngau <[EMAIL PROTECTED]> wrote:
>
> Can someone figure out what's going on. This is the only change
> I made to this table. Basically I don't want any duplicate rows, so
> I setup 4 fields to be my primary key.
>
> When I do a simple select query it takes nearly 30 seconds to complete.
Quoting nngau <[EMAIL PROTECTED]>:
Can someone figure out what's going on. This is the only change
I made to this table. Basically I don't want any duplicate rows, so
I setup 4 fields to be my primary key.
If you don't want any duplicate rows, use UNIQUE, all those primary keys will
just take
Can someone figure out what's going on. This is the only change
I made to this table. Basically I don't want any duplicate rows, so
I setup 4 fields to be my primary key.
When I do a simple select query it takes nearly 30 seconds to complete.
This is affecting my websites and taking a very long t
@lists.mysql.com
Subject: Re: Table with multiple primary keys - How
It is not possible to have more than one PRIMARY
key per table.
Maybe you need to use one PRIMARY key as the main index into
the table, then use UNIQUE or KEY which is a synonym for
INDEX on the other two columns.
This book will
It is not possible to have more than one PRIMARY
key per table.
Maybe you need to use one PRIMARY key as the main index into
the table, then use UNIQUE or KEY which is a synonym for
INDEX on the other two columns.
This book will help you ALOT with designing tables.
It will also teach you how
- Original Message -
From: "fbsd_user" <[EMAIL PROTECTED]>
To:
Sent: Tuesday, March 07, 2006 11:40 PM
Subject: Table with multiple primary keys - How
What I am trying to do here is have 3 separate primary keys.
Creating a mysql select on either of the Logon_id
In the last episode (Mar 07), fbsd_user said:
> What I am trying to do here is have 3 separate primary keys. Creating
> a mysql select on either of the Logon_id, email_addr, or last_name
> fields will do a single read to the matching value. Like having 3
> different indexes into the same table.
C
What I am trying to do here is have 3 separate primary keys.
Creating a mysql select on either of the Logon_id, email_addr,
or last_name fields will do a single read to the matching value.
Like having 3 different indexes into the same table.
I don't want those 3 field concatenated together as a
On Sunday 15 May 2005 20:31, Dan Bolser wrote:
> You must mean a multipart primary key with three parts :)
>
> or "multiple-column indexes"
>
> That is what I would do (use a multiple-column index (primary key) - its
> kinda based on opinion, but I think you should let the real data be the
> prima
>> What I want to ensure is that there are no duplicate records when
>considering the three foreign keys above. Would it be appropriate to remove
>the single primary and replace with three multiple primary keys? Is there a
>performance impact when doing this. this seems overly complex
ing the three foreign keys above. Would it be appropriate to remove
the single primary and replace with three multiple primary keys? Is there a
performance impact when doing this. this seems overly complex and wonder if
I should be breaking the table up to simplify? Any suggestions would be
appreciate
foreign keys above. Would it be appropriate to remove the single
primary and replace with three multiple primary keys? Is there a performance
impact when doing this. this seems overly complex and wonder if I should be
breaking the table up to simplify? Any suggestions would be appreciated.
Bob
lt;[EMAIL PROTECTED]>
Sent: Wednesday, February 11, 2004 2:49 PM
Subject: Referencing multiple primary keys
Hello, I am banging my head against the wall trying to figure out how to
construct a foreign key towards a table with a primary key consisting of two
columns. I have been googling around
Hello, I am banging my head against the wall trying to figure out how to construct a
foreign key towards a table with a primary key consisting of two columns. I have been
googling around and thought this would work, but it just gives me an ERROR 1005.
ALTER TABLE testDB ADD FOREIGN KEY (fkey1, f
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