Limiting user records

Hi,
What is the best way to limit the number of records a user can insert
into a table. Basically, I want to set something like 50 records. If
the user tries to insert the 11th record, I want the action to FAIL,
therefore firing some SQL Error. I want to be able to customize this
error too.
So, what is the best way? Is it possible to get an example please?
Tascien
Your specs are inconsistent. You say you want to limit it to 50 rows but it
should fail on the 11th row. Could you post your DDL, sample data and
expected results?
Tom
Thomas A. Moreau, BSc, PhD, MCSE, MCDBA
SQL Server MVP
Columnist, SQL Server Professional
Toronto, ON Canada
www.pinpub.com
<tascienu@.ecoaches.com> wrote in message
news:1136420757.396966.83240@.o13g2000cwo.googlegro ups.com...
Hi,
What is the best way to limit the number of records a user can insert
into a table. Basically, I want to set something like 50 records. If
the user tries to insert the 11th record, I want the action to FAIL,
therefore firing some SQL Error. I want to be able to customize this
error too.
So, what is the best way? Is it possible to get an example please?
Tascien
|||tascienu@.ecoaches.com wrote:
> Hi,
> What is the best way to limit the number of records a user can insert
> into a table. Basically, I want to set something like 50 records. If
> the user tries to insert the 11th record, I want the action to FAIL,
> therefore firing some SQL Error. I want to be able to customize this
> error too.
> So, what is the best way? Is it possible to get an example please?
> Tascien
Do you mean total rows in a table or the number of rows executed in a
single insert statement? If you want total rows in a table then you'll
have to tag each row with the user name. You can use an instead of
insert trigger to first query the underlying table for the number of
rows owned by the user and add this to the number of rows in the
inserted table. If you want to limit the number in a single insert (as
in INSERT INTO... SELECT FROM) you can also use an instead of insert
trigger, but this time check COUNT(*) from inserted to make sure it's
not over the limit. Or maybe you want something else altogether...
David Gugick
Quest Software
www.quest.com
|||Sorry, I was giving an example... Let's say, i limit to 3 records...
1 First
2 Second
3 Third
4 Raise Error "You have reached the maximum allowed rows"
Tascien
|||create table test
(value char(100))
go
create trigger testrig
on test
instead of
insert
as
begin
if (select count(*) from test) >= 3
begin
rollback
raiserror ('Number of rows exceeds 3',16,1)
end
else
insert into test select value from inserted
end
go
insert into test values('first')
insert into test values('second')
insert into test values('third')
insert into test values('fourth')
go
select * from test
|||Wonderful. That is what i was looking for. By the way, adding a
Select Count(*) trigger for each insert... is it a performance issue
when the table gets big?
Tascien
|||tascienu@.ecoaches.com wrote:
> Wonderful. That is what i was looking for. By the way, adding a
> Select Count(*) trigger for each insert... is it a performance issue
> when the table gets big?
> Tascien
Yes. You might want to consider creating a clustered index on the user
column. But it is a concern you should account for before the table gets
too large.
David Gugick
Quest Software
www.quest.com
|||Yes you need to create an clustered index on it.
One more thing that I found about my last post is,
Suppose two users want to insert record and number of records are 2 in
the table when both of you checked it.so both of you will issue insert
commands. So first of them two should be succeeded. You have to put a
lock on the table.
so while you check you have to give lock hint of holdlock.
select count(*) from test (holdlock)
But then at a time only one user can insert into the table.
What is the reason for a table to limmit its number of records to some
number of rows.
Instead you can create a view to filter number of rows.
Regards
Amish
*** Sent via Developersdex http://www.codecomments.com ***
|||The reason I am limiting is not a critical one. I just don't want some
of my customers to exceed a number of records I assign to them. If they
exceed by 1 or 2, it should be fine...
Once again, thanks for help.
Tascien
|||Ok in that case you dont need to put hold lock is you are ready to
accept 1 or 2 more records then decided. It will not create locks on
the table.
Regards
Amish

Limiting user records

Hi,
What is the best way to limit the number of records a user can insert
into a table. Basically, I want to set something like 50 records. If
the user tries to insert the 11th record, I want the action to FAIL,
therefore firing some SQL Error. I want to be able to customize this
error too.
So, what is the best way? Is it possible to get an example please?
TascienYour specs are inconsistent. You say you want to limit it to 50 rows but it
should fail on the 11th row. Could you post your DDL, sample data and
expected results?
Tom
----
Thomas A. Moreau, BSc, PhD, MCSE, MCDBA
SQL Server MVP
Columnist, SQL Server Professional
Toronto, ON Canada
www.pinpub.com
<tascienu@.ecoaches.com> wrote in message
news:1136420757.396966.83240@.o13g2000cwo.googlegroups.com...
Hi,
What is the best way to limit the number of records a user can insert
into a table. Basically, I want to set something like 50 records. If
the user tries to insert the 11th record, I want the action to FAIL,
therefore firing some SQL Error. I want to be able to customize this
error too.
So, what is the best way? Is it possible to get an example please?
Tascien|||tascienu@.ecoaches.com wrote:
> Hi,
> What is the best way to limit the number of records a user can insert
> into a table. Basically, I want to set something like 50 records. If
> the user tries to insert the 11th record, I want the action to FAIL,
> therefore firing some SQL Error. I want to be able to customize this
> error too.
> So, what is the best way? Is it possible to get an example please?
> Tascien
Do you mean total rows in a table or the number of rows executed in a
single insert statement? If you want total rows in a table then you'll
have to tag each row with the user name. You can use an instead of
insert trigger to first query the underlying table for the number of
rows owned by the user and add this to the number of rows in the
inserted table. If you want to limit the number in a single insert (as
in INSERT INTO... SELECT FROM) you can also use an instead of insert
trigger, but this time check COUNT(*) from inserted to make sure it's
not over the limit. Or maybe you want something else altogether...
David Gugick
Quest Software
www.quest.com|||Sorry, I was giving an example... Let's say, i limit to 3 records...
1 First
2 Second
3 Third
4 Raise Error "You have reached the maximum allowed rows"
Tascien|||create table test
(value char(100))
go
create trigger testrig
on test
instead of
insert
as
begin
if (select count(*) from test) >= 3
begin
rollback
raiserror ('Number of rows exceeds 3',16,1)
end
else
insert into test select value from inserted
end
go
insert into test values('first')
insert into test values('second')
insert into test values('third')
insert into test values('fourth')
go
select * from test|||Wonderful. That is what i was looking for. By the way, adding a
Select Count(*) trigger for each insert... is it a performance issue
when the table gets big?
Tascien|||tascienu@.ecoaches.com wrote:
> Wonderful. That is what i was looking for. By the way, adding a
> Select Count(*) trigger for each insert... is it a performance issue
> when the table gets big?
> Tascien
Yes. You might want to consider creating a clustered index on the user
column. But it is a concern you should account for before the table gets
too large.
David Gugick
Quest Software
www.quest.com|||Yes you need to create an clustered index on it.
One more thing that I found about my last post is,
Suppose two users want to insert record and number of records are 2 in
the table when both of you checked it.so both of you will issue insert
commands. So first of them two should be succeeded. You have to put a
lock on the table.
so while you check you have to give lock hint of holdlock.
select count(*) from test (holdlock)
But then at a time only one user can insert into the table.
What is the reason for a table to limmit its number of records to some
number of rows.
Instead you can create a view to filter number of rows.
Regards
Amish
*** Sent via Developersdex http://www.codecomments.com ***|||The reason I am limiting is not a critical one. I just don't want some
of my customers to exceed a number of records I assign to them. If they
exceed by 1 or 2, it should be fine...
Once again, thanks for help.
Tascien|||Ok in that case you dont need to put hold lock is you are ready to
accept 1 or 2 more records then decided. It will not create locks on
the table.
Regards
Amish