dynamic procedure creation - possible?

Hi Gurus
I am trying to develop an application around SQL server. The app allows
the user to input a where clause at runtime, which the application runs
against. The only way the app can use the input where clause is by
building an SQL statement including the where clause, and then calling
sp_executeSQL against it. This is inefficient; ideally I would like to
compile the SQL statement (as it will be used multiple times) - but how
can I do this? I cannot call CREATE PROCEDURE, as that cannot be done
from inside another statement (it must be done explicitly with a
hardcoded where statement).
Is there any wat I can improve on building the statement and calling
sp_executeSQL every time I need to run it?
"neilsolent" <neil@.solenttechnology.co.uk> wrote in message
news:1169494423.824216.35130@.38g2000cwa.googlegrou ps.com...
> Hi Gurus
> I am trying to develop an application around SQL server. The app allows
> the user to input a where clause at runtime, which the application runs
> against. The only way the app can use the input where clause is by
> building an SQL statement including the where clause, and then calling
> sp_executeSQL against it. This is inefficient;
Why do you think that? SQL Server will cache and reuse SQL queries sent
using sp_executesql, especially if you use parameter markers in the query.
See
Batch Compilation, Recompilation, and Plan Caching Issues in SQL Server 2005
http://www.microsoft.com/technet/prodtechnol/sql/2005/recomp.mspx
Execution Plan Caching and Reuse
http://msdn2.microsoft.com/en-us/library/aa175244(SQL.80).aspx

> ideally I would like to
> compile the SQL statement (as it will be used multiple times) - but how
> can I do this? I cannot call CREATE PROCEDURE, as that cannot be done
> from inside another statement (it must be done explicitly with a
> hardcoded where statement).
> Is there any wat I can improve on building the statement and calling
> sp_executeSQL every time I need to run it?
>
No. That is really a perfectly fine thing to do. Consider using parameter
markers in sp_executesql to get query plan reuse and reduce compilations.
However if the volume of these dynamic queries is not great, or the cost of
each query to execute is large, then plan reuse may not be important or even
desirable.
David
|||Thanks very much for that David.
The queries don't have parameters - they are always exactly the same
every time they are run (the user may change the where clause, but this
will be a very infrequent event). However, there could be up to 255 of
these queries (and where clauses), which could potentially all get
called (in series) every time a row is inserted into a certain key
table. A row is inserted in the key table possibly several times a
second (worst case).
|||"neilsolent" <neil@.solenttechnology.co.uk> wrote in message
news:1169495992.357049.50780@.m58g2000cwm.googlegro ups.com...
> Thanks very much for that David.
> The queries don't have parameters - they are always exactly the same
> every time they are run (the user may change the where clause, but this
> will be a very infrequent event). However, there could be up to 255 of
> these queries (and where clauses), which could potentially all get
> called (in series) every time a row is inserted into a certain key
> table. A row is inserted in the key table possibly several times a
> second (worst case).
>
Ok, 255 different queries isn't much at all. I would just let SQL Server
cache them.
David
sql