Database Discussion Boards

Re: SQL query

Krish - KP9-Jun-07 3:32

Krish - KP

9-Jun-07 3:32

this can be done using two methods
1. outer join
2. not exists
you can choose one on these two.

Regards
KP

Local databse

maksim3108-Jun-07 16:38

maksim310

8-Jun-07 16:38

Hi,

I am writing a program in VB.NET (VS2005 Pro) that essentially simulates an neurology experiment. This program's data shoould consiste of 8 independent tables, each having 13 columns and up to 100,000 rows in each table. To make it simpler, all data will be in string format.
Other requirments:
1. The tables needs to be sortable like a dictioanry where 1 column will act as a key.
2. The user needs to be able to see the data in a tabular format.
3. The data must be held on the user's local machine, not a server and not remotley.
4. Needs to easily be readable by Excel, doesn't matter how. It can convert to an XML file and then somehow be automatically converted to xls.

I am thinking of using a databse becasue I would like to eventually create a login screen to link previous experiment values to a user, but that is not essential. I used dynamic multi-dimensiaonal arrays but find it difficult to work with, and extremley difficult to sort.

I was looking at the idea of using an XML database which will probbaly solve any issues of excel compatability as well as provide support for displaying the information on a website sometime in the future. I can't figure out how this all works.

Can anyone recommend a way to display a large amounts of generated data on a local computer, and almo make it save-able. I also like Oracle's 10g Express thing, but don't know if it would work for my specific problem becasue the cusotmer support people at Oracle don't speak English very well.

Thank You,

Maksim
UCLA, Neurology

Re: Local databse

Sathesh Sakthivel8-Jun-07 16:44

Sathesh Sakthivel

8-Jun-07 16:44

My Best Suggestion is go with XMl.

Regards,

Satips. Rose | [Rose]

Re: Local databse

Expert Coming8-Jun-07 22:29

Expert Coming

8-Jun-07 22:29

I think performance wise a database would be alot faster. You can sort by column in multiple ways as well as only pull the data you want by using queries. Even if speed isn't a factor, I think you'll find working with databases easier.

The best way to accelerate a Macintosh is at 9.8m/sec² - Marcus Dolengo

Re: Local databse

maksim3109-Jun-07 9:37

maksim310

9-Jun-07 9:37

How would it work with ym clients, do they need to install a database software? I want something that is embedded into my aplication that won't require the user to do anything more than install the application.

Connect to server

emiralp8-Jun-07 10:36

emiralp

8-Jun-07 10:36

Hi ,

As you all know, in sql server, the program must be connected to a server to work properly(execute db, etc.). How can I make my pc work like a server, then connect to it in sql server 2005.

thanks !

Re: Connect to server

Expert Coming8-Jun-07 22:37

Expert Coming

8-Jun-07 22:37

I don't understand the question. Do you mean how do you make you computer a SQL Server? Simple. Install SQL Server.

The best way to accelerate a Macintosh is at 9.8m/sec² - Marcus Dolengo

Re: Connect to server [modified]

emiralp8-Jun-07 23:04

emiralp

8-Jun-07 23:04

The problem is, I write my computer name at the start of the sql server manager studio(to the server name) but doesn't connect, it tries and then it throws an error message.

the message is ;
An error has occured while establishing a connection to the server.
When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections.(provider: Named Pipes Provider,error:40-Could not open a connection to SQL Server)(Microsoft SQL Server,Error :53)

what must I do ?

-- modified at 5:49 Saturday 9th June, 2007

Re: Connect to server

Paul Conrad9-Jun-07 11:03

Paul Conrad

9-Jun-07 11:03

You need to go into the configuration manager and tweak the settings to allow remote connections.

"The clue train passed his station without stopping." - John Simmons / outlaw programmer

CRecordset for multi-table recordsets

paulosuckow8-Jun-07 8:28

paulosuckow

8-Jun-07 8:28

I need help with accessing a table in a mutlitable recordset. I have :

3 tables as follows

CString COrderSet::GetDefaultSQL()
{
return _T("[tbladdress],[tblcontact],[tbltest]");
}
and I am trying to add new record to each table individually.

My "m_pSet" that is a joint recordset of these three. How can I get a handle or pointer to each table.

When I do : m_pSet->AddNew() I get a "recordset read-only" error msg. which make sense because it doesn't know where to add a new record. (note that m_pSet is a joint set.)

Please help.

paulo.

top rows

vasini8-Jun-07 7:30

vasini

8-Jun-07 7:30

Hi,
I need to generate a report for top 10 share holders. its not that the first top 10 values. Its the top 10 share holders ( values). I am writing the query in sql server. Please help me to get top 10 share holder values.

Thank you.

Vasini

Vasini

Re: top rows

Colin Angus Mackay8-Jun-07 9:13

Colin Angus Mackay

8-Jun-07 9:13

SELECT TOP 10 *<br />
FROM Shareholders<br />
ORDER BY whatEverColumnMakesThemTop

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Re: top rows

Harini N K10-Jun-07 19:33

Harini N K

10-Jun-07 19:33

Colin Angus Mackay wrote:
SELECT TOP 10 *
FROM Shareholders
ORDER BY whatEverColumnMakesThemTop

Put Descending in the Order by clause to get max. top 10 shareholders. Smile | :)

Harini

SQL Server Speed

3fonov8-Jun-07 3:23

3fonov

8-Jun-07 3:23

What can cause slowness of SQL Server 2005 Enterprise?
When start same DB on Enterprise and Express, express are mach more faster (100 times)
Thanks for advises.

Re: SQL Server Speed

Mike Dimmick8-Jun-07 9:20

Mike Dimmick

8-Jun-07 9:20

Typically your databases on Express are set to the Simple recovery model. This keeps only the transaction logs required to roll back active transactions. It rapidly overwrites the log records once the corresponding transaction is committed.

In contrast databases on the true server editions of SQL Server default to the Full recovery model, which logs everything that's done and keeps log records until the log is backed up, in order that recovery can occur to the point of failure if the data files are lost (and you restore a full backup). If you're not backing up the transaction log through a SQL Server-aware product, they simply keep growing. This may well take longer to scan on opening a database.

Also, SQL Server Express Edition only actually opens databases and performing the roll forward of logged committed operations and rollback of logged uncommitted operations when that database is accessed (this is the 'auto close' option). The full editions of SQL Server open and recover all database at service startup.

The time to perform recovery is also affected by the disk subsystem you're running the process on - it will be directly proportional to the read speed of the disks. If you're running on RAID 5, check that you haven't got a failed disk - your read speed will have gone through the floor. You will also get a complete failure if another drive fails.

Stability. What an interesting concept. -- Chris Maunder

Why this is faster?

Arun.Immanuel8-Jun-07 2:33

Arun.Immanuel

8-Jun-07 2:33

Here are the 2 queries I tested for speed.

<br />
select replace(convert(nvarchar(10),getdate(),108),':','') <br />
from tblName

<br />
select replace(convert(nvarchar(10),getdate(),108),':','')*1<br />
from tblName

The former took 6 seconds and the latter took only 4 seconds.
The table tblName has around 5 lakhs of rows.

Confused | :confused:

Regards,
Arun Kumar.A

Re: Why this is faster?

Colin Angus Mackay8-Jun-07 2:38

Colin Angus Mackay

8-Jun-07 2:38

Arun.Immanuel wrote:
5 lakhs of rows

Which means?

Re: Why this is faster?

Rob Graham8-Jun-07 2:51

Rob Graham

8-Jun-07 2:51

Colin Angus Mackay wrote:
Reporting

I think it means he's of the Indian persuasion.

Re: Why this is faster?

Arun.Immanuel8-Jun-07 2:54

Arun.Immanuel

8-Jun-07 2:54

Yes, You are right. Smile | :)

Regards,
Arun Kumar.A

Re: Why this is faster?

Arun.Immanuel8-Jun-07 2:52

Arun.Immanuel

8-Jun-07 2:52

I have 5,00,000 rows in the table tableName

Regards,
Arun Kumar.A

Re: Why this is faster?

andyharman8-Jun-07 3:38

andyharman

8-Jun-07 3:38

This one creates a column that takes about 13 bytes:

select replace(convert(nvarchar(10),getdate(),108),':','') <br />
from tblName

While this one casts the result into an integer (which takes just 4 bytes):

select replace(convert(nvarchar(10),getdate(),108),':','')*1<br />
from tblName

The second is probably only faster because SQL Server can store the results in less space (or the data takes less packets to pass across your network.

Re: Why this is faster?

Arun.Immanuel8-Jun-07 5:21

Arun.Immanuel

8-Jun-07 5:21

Thank you very much Smile | :)

Regards,
Arun Kumar.A

How to alter table

rzthebeginner8-Jun-07 2:21

rzthebeginner

8-Jun-07 2:21

I want to alter a table using sql query.In that i want to insert new field between other fields,not at the last position.How to do that?

Re: How to alter table

Arun.Immanuel8-Jun-07 2:37

Arun.Immanuel

8-Jun-07 2:37

Why do you want to add the column inbetween?

What problem do you face when you add the column at the last?

No matter where the column positions are.

Always try to include the column names along with the statements like:

<br />
select col1,col2 from tblName<br />
<br />
<br />
insert into tblName(col1,col2) values(val1,val2)

Regards,
Arun Kumar.A

Re: How to alter table

Rob Graham8-Jun-07 3:02

Rob Graham

8-Jun-07 3:02

In general you can't, unless you are willing to destroy all the columns that are to come after the new one, then add them back.

In most cases, column order at definition time is not particularly relevant. Unless they are part of a clustered index, the definition order has no relation to the storage order on disk. The only impact is if you do a query of the form "select * from tablename", the definition order becomes the default order for returning the columns. This is bad practice anyway, since it usually means you are fetching more data than you really need; "select col3,col1,col2, col4 from tablename" is the recommended approach, and in that case you have specified whatever return column order you desire.

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