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I went through some of my colleague's (who left for another project) SQL code and I encountered the following where clause (part of it, actually):
where ...
convert(varchar(25), td.CreationDate, 111) >= (getutcdate() - @NumOfDays) and
convert(varchar(25), td.CreationDate, 111) <= (getutcdate())
...
This is part of a larger where and it narrows the search to rows younger than @NumOfDays days.
The problem I see here is that the convert(varchar(25), td.CreationDate, 111) must be executed on every row in the table (Am I right here?). This query will tend to become slower each day as the table grows (and it is expected to grow a couple thousands of rows per day).
Am I right to say that this query will eventually come to a crawl or an I just smoking some bad stuff?
NOTE: td.CreationDate does not have to be converted to its date part only. The time part can stay.
Would it be right to replace it by:
td.CreationDate >= dateadd(day, -@NumOfDays, getutcdate()) and
td.CreationDate <= getutcdate()
And I even suspect that
td.CreationDate >= dateadd(day, -@NumOfDays, getutcdate())
would be sufficient since the td.CreationDate field cannot be in the future (or I am missing something here).
Tx
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Why do you ask, you already gave the answer. To speed things further up, you can create a non-unique index on td.CreationDate. Always check the execution plan on suspicious statements, it will tell you the cost of the statement. Twiddle around till you find the cheapest, and youre as happy as a cloud. Performance differences can make up a factor between 2 and several thousand times faster.
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Tx for your answer, I just wanted confirmation on this.
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Is there any way that SQL server can call any application running on the same machine. I have SQL server runing on a machine. I also got another application running on the machine. I want that SQL server to call this running application. Is it possible ??
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If I use dataadaptor to retrieve some data from database, then use fill method to put them into my dataset object instance, then is there any way to retrive the data stored in my dataset object? Thanks!
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dataset.Tables["tablename"].Rows[1]["columnname"]
I rated this article 2 by mistake. It deserves more. I wanted to get to the second page... - vjedlicka 3:33 25 Nov '02
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How to convert from sql to oledb as "Catch Exp As oledbException
If Exp.Number = 2627"
How to modify this program? Could anyone let me know to slove it program?
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I'm a veteran web apps developer who is now interested in building more desktop-oriented apps using C#/.NET, since it provides such an elegant framework for doing so.
I'm quite experienced in using sql server in all types of web applications with all types of technologies, however, what I'm not so familiar with is using MSDE as an alternative to access in stand-alone windows apps.
What I'm looking for are some "beginners" guides on how this is done.
How do I package a sql server database into an MSDE db and then package it up with my desktop apps so they're "stand-alone" from a database server?
How do I transfer an existing sql server database into an msde db and use it separately from a database server?
I've only so far been able to find very vague examples on the web on how to do these things.
Thanks in advance!!
-v
****************************
V. Jenks
www.scientifik.com
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emm... If you are familiar with MS SQL, then msde is not a trouble for you, except you does not have GUI interface to manage it... but the best thing is you can always use MS SQL Enterpise Manager to manage it.
knowledge is power
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MSDE IS Sql server, just with fixed tuning optimized for about 5 users, 2GB limit on Database size, no replication publication, no OLAP, etc. and no GUI tools.
The MSDE redist will install SQL server on your clients machine. The silent install has a lot of assumed defaults (C so you may want to study how to modify the redist install scripts to customise the installation.
Aroogala wrote:
How do I package a sql server database into an MSDE db and then package it up with my desktop apps so they're "stand-alone" from a database server?
How do I transfer an existing sql server database into an msde db and use it separately from a database server?
MSDE database == SQL database (same data files...): You can create databases with SQL developer (or any other "full" edition), detach them and have your install process attach them to the new server, aternatively you could export scripts and create the client db by reading the scripts during your install (osql is included with MSDE).
Restoring a backup also works...
Some ideas are so stupid that only an intellectual could have thought of them - George Orwell
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I am creating tables dynamically using stored procedures, and would like to use a parameter variable as the table_name identifier. The SPs are implemented in T-SQL scripts. I am currently using literal identifiers as usual, then renaming the tables via sp_rename. For example (with SET QUOTED_IDENTIFIER ON):
CREATE PROC spCreateTable (@TableName sysname)
AS
BEGIN
CREATE TABLE "_TempTableName_" (
)
EXEC sp_rename '_TempTableName_', @TableName --rename to desired name
END
GO
Does anyone know how I could use @TableName directly or indirectly in the CREATE TABLE statement?
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CREATE PROC spCreateTable (@TableName sysname)
AS
BEGIN
declare @Tb NVarchar(80)
select @tb = N'[dbo].[' + @tb + N']'
CREATE TABLE @Tb(
) ON [PRIMARY]
END
GO
works for me...
Some ideas are so stupid that only an intellectual could have thought of them - George Orwell
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That was what I originally did, but I keep getting invalid identifier errors with SQL Server 2K. I was hoping this was just something specific to T-SQL, as opposed to the syntaxes I am more familiar with. There must be a switch I'm incorrectly setting somewhere, since your script files parse correctly. Thanks for confirming my original approach is not what I need to change.
Cheers
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Hmmm.. This works fine with SQL 2k for me, However I usually don't change the Quoted Identifiers from the default (which I believe is off...). I always rebuild the table name into an NVARCHR local variable and delimit with the []. I think whwn we went from SQL7 to 2k the table owner part also became necessary [dbo].
The invalid identifiesr error suggests either white space or illegal characters in the name...
Some ideas are so stupid that only an intellectual could have thought of them - George Orwell
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Hi all - I have ten application servers all running mdac 2.6 RTM. Each of the client's applications are running fine.
However, I also have an in-house VB utility that needs to be ran periodically. When this is ran, it fails with an "Unable to load dll" error.
I tracked this down to the msadodc.ocx (ADO Data Control). The project compiles fine on 9/10 servers, but on this one I can't even add the ado control to the toolbox.
I've tried the following steps in vain trying to fix this problem:
1. Unregistered & Reregistered the file (successfully)
2. Reviewed & checked for dependencies using the dependency walker.
3. Utilized the MDAC Component checker for inconsistencies.
4. Verified all registry entries & GUIDs.
5. Ran the VBCli.exe to ensure all development licenses were OK.
All servers are running VB Enterprise sp5.
I don't want to upgrade MDAC to 2.7 as this may cause problems with existing applications...ANY IDEAS AT ALL WOULD BE APPRECIATED!!!
Thanks!
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I noticed that when I use Addnew() followed by Put_Value()and don't call Update(), the values are stored in the database. I'm using VC++ for this. Any ideas as to why this is.
Thanks
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Oracle Listener
Hi
when trying to connect oracle 6i to 8i on the same machine, i'm getting this error message:
ORA-12224:TNS: no listener
i think i have to turn the listener on.
How can i check the status of the listener?
How can i turn it on?
i'm running Win98.
thank you
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What do you mean by connect 6i to 8i? If you mean using 6i client to connect to 8i server, then won't work - need as a minimum 8 client.
"Now I guess I'll sit back and watch people misinterpret what I just said......"
Christian Graus At The Soapbox
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Im trying to use ADO in Visual C++. I would like to retrieve each field type.
ie , text, int etc
Thanks
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Use get_Type property of the Field object
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How do I add a timestamp to SQL db?? I am using CDatabase and CRecordSet.
Thanks,
grahamoj.
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Hi,
Can anyone let me know if the usage of typed datasets in ADO.NET has any serious limitations compared to untyped datasets ?
Thanks in advance,
Kanchana
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Usually it's untyped datasets that are considered more limited than typed ones, unless you are accessing data you know little about. However, it really depends on what you want to do.
Typed datasets essentially just means the types are known and understood, whereas untyped ones are generic, and hence less is known (and needs to be known). Typed sets are much more efficient, since more work is done at compile time than at runtime. Also, typed sets can do more error checking to avoid mistakes. Commonly, the goal is to use typed sets whenever possible.
Untyped sets can be a little simpler at first, since less needs to be specified, column names do not need to be known, etc. If you do need to work with untyped sets at some point, it's useful if you can have a schema automatically generated, so you can move to typed sets. That will depend on the situation, though.
If you do not consider needing to know what types to deal with to be a problem, then I cannot think of any serious limitations with typed datasets.
Cheers
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I need each param parsed out of this string. I am having trouble parsing if the vars vary in length.
Data: ec=TTT&oc=CRM&tot=501&UID=88997
<br />
(SELECT<br />
ID, IP, TID, TheUserDetails.UserID as UserID, <br />
--Parsing<br />
Querystring,<br />
SUBSTRING(Querystring, CHARINDEX('ec=',Querystring) + 3, CHARINDEX('&', Querystring) - 4) as EC,<br />
SUBSTRING(Querystring, CHARINDEX('oc=',Querystring) + 3, CHARINDEX('&', Querystring) - 4) as OC,<br />
SUBSTRING(Querystring, CHARINDEX('tot=',Querystring) + 4, CHARINDEX('&', Querystring) - 5) as TOT,<br />
SUBSTRING(Querystring, CHARINDEX('uid=',Querystring) + 4, 50) as UID<br />
FROM WebLog l LEFT JOIN<br />
dbo.TheUserDetails ON <br />
l.TID = TheUserDetails.TrackID)<br />
Alex Polajenko
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Alex
If the parameters are always in the same order then couldn't you use something like:
SUBSTRING(Querystring,<br />
CHARINDEX('ec=',Querystring) + 3,<br />
CHARINDEX('&oc=', Querystring) - (CHARINDEX('ec=',Querystring) + 3)<br />
) as EC
The third argument for SubString calculates the size by finding the difference between the starting position of "oc=" and "ec=". Note that I haven't tried this because I'm at a client's site today.
Good luck
Andy Harman
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