Database

Re: How to set up a database and use it

24-Jan-09 6:59

I would advise you to get a few good books, but to your questions:

toprogramminguy wrote:
I don't know which database to use which is part of my problem

You could use SQL Server Express Edition. Download, install it and start using by creating a db, tables etc.

toprogramminguy wrote:
I've tried using sql server but I don't know how to create a connection to it from a program

You use SqlConnection[^]. Define a connection string and open the connection. Good example in the link in examples.

toprogramminguy wrote:
I don't know what to use as a user id or password

If you use integrated security, you don't need separate username and password. If you use SQL Server authentication, you use SA as user and the password is defined during setup.

toprogramminguy wrote:
I had an oleDb database set up and it was working fine but I don't know how to write data to it

Don't know what this means. OleDb is a way to connect to a database, not a database.

One book you could start with is: Beginning C# 2008 Databases: From Novice to Professional [^]

The need to optimize rises from a bad design.My articles[^]

toprogramminguy24-Jan-09 7:08

toprogramminguy

24-Jan-09 7:08

I mean an mdb database. I thought that was an ole db database. Thanks anyway Smile | :)

Re: How to set up a database and use it

Wendelius24-Jan-09 7:13

Sql statement as an input parameter to stored procedure

24-Jan-09 7:13

toprogramminguy wrote:
I mean an mdb database

Okay, I see. Mdb is a SQL Server database file which can be attached to an existing SQL Server instance and then it can be used.

toprogramminguy wrote:
Thanks anyway

You're welcome Smile | :)

The need to optimize rises from a bad design.My articles[^]

Hemant Thaker24-Jan-09 3:14

Hemant Thaker

24-Jan-09 3:14

Hi..
This is the question I was asked in an interview...

say.. I am executing a stored procedure as under
exec sp_temp("select * from emp")

how will i write in stored procedure to execute this query if i receive this value in one parameter say..@sql as under

create procedure sp_temp
@sql varchar(100)
as

begin
-- what would i write here to execute query in @sql
end

////////////////////////
As I didn't reply to interviewer, I want to know this....
thanks....
Hemant

By:
Hemant Thaker

Re: Sql statement as an input parameter to stored procedure

Wendelius24-Jan-09 4:01

Windows Firewall blocks SQL Connection

24-Jan-09 4:01

You could have written:

create procedure sp_temp
@sql varchar(100)
as
begin
   exec (@sql)
end

But then I would have added that it would have been a bad design...

The need to optimize rises from a bad design.My articles[^]

Hampden Tech24-Jan-09 2:26

Hampden Tech

24-Jan-09 2:26

I am trying to connect to a SQL-2005 Remote server through several VS-2008 applications. Two are web applications and the other is a VB.Net application. In all cases, the connection fails and the error message in the local Windows Event log is #26, suggesting that possibly the SQL server does not allow remote connections.

I know that the remote SQL server is configured correctly because I have gone through all of the steps (Surface Area Configuration, SQL Config, etc). More importantly, the connection through these applications is fine when I disable my local Windows Firewall.

On my Firewall I have created Exceptions for both SQL Server and SQL Browser. I have opened TCP port 1433 and UDP port 1434.

In all of my research, this is the extent of the solutions provided and so I am at a loss. Turning off the Firewall while debugging is a temporary solution and somewhat safe since my network is protected by a separate Firewall device, however, I would like to resolve this issue. I think there are enough developers out there having this same problem so hopefully someone has resolved it beyond the solutions I have tried.

Thanks if you can help!

Wendelius24-Jan-09 2:48

24-Jan-09 2:48

Few questions:
- tcp/ip is enabled? (firewall also blocks named pipes)
- what tcp port your sql server is listening?
- do you use dynamic ports?

The need to optimize rises from a bad design.My articles[^]

Hampden Tech24-Jan-09 3:19

Hampden Tech

24-Jan-09 3:19

TCP/IP is enabled as well as named pipes.
According to the registry, Dynamic ports is enabled which may explain the problem. After messing with this and restarting SQL server (still using Dynamic Ports) I was able to connect. The last Dynamic Port used is 4316. The weird part is that I'm not opening port 4316 on my Firewall and yet the applications can now connect.

It seems as though I should configure the server to listen on a static port (or ports).

Hampden Tech24-Jan-09 3:30

Hampden Tech

24-Jan-09 3:30

Okay, here's a follow-up. The reason Dynamic IP address might have been enabled on this server is that there is also an instance of SQL-2000 running and that must have been using port 1433. I used the dynamically assigned port # that I found in the registry as the new Static port number for IPALL and restarted the SQL service. I then opened this port in my local firewall.

I can connect to the SQL server through the application. I'm not sure if I have completely solved my problem but I have opened up my understanding of the issue.

Thanks for the reply Mike. You pushed me in the right direction!

Wendelius24-Jan-09 3:55

SQL Replication Question Please be kind - Newbie here! [modified]

24-Jan-09 3:55

Hampden Tech wrote:
there is also an instance of SQL-2000 running and that must have been using port 1433

Dynamic ports is fine. If you have another SQL Server (the older one) in port 1433, you should open 1434 (or some other port) for tcp traffic for this SQL Server (I recall you opened udp). Also make sure that the newer SQL Server is listening on 1434. When changing the network protocols, prefer using SQL Server configuration manager in SQL Server 2005.

Hampden Tech wrote:
Thanks for the reply Mike

You're welcome.

The need to optimize rises from a bad design.My articles[^]

joey9363523-Jan-09 12:42

joey93635

23-Jan-09 12:42

I have an application that uses SQL Server 2005 Express at site A.
I now have users that would like to have access to this application from site B.
At site B I have a server that also has SQL Server 2005 Express.
I would like to explore the use of SQL replication technology to see if that would work for when a user connects to the database, it will pull from its respective local DB. These sites are currently connected to each other through an IPSEC tunnel through our WAN link.

Does SQL Server 2005 support Database replication?

Is it relatively easy to setup?

Can someone point me in the general direction of where I can get some step-by-step directions?

Thank you all very much,

Joey

modified on Friday, January 23, 2009 7:04 PM

Re: SQL Replication Question Please be kind - Newbie here!

Wendelius23-Jan-09 21:13

Re: SQL Replication Question Please be kind - Newbie here!

23-Jan-09 21:13

SQL Server supports replication and one-way replication is quite easy to set up. Two-way replication (merge) is much more complex (this is true for all databases).

You can read basics for replication for example here: SQL Server Replication[^]

However since you're using Express edition in all nodes, it won't be possible to setup full replication. Express Edition can only be a subscriber in replication scenarios so you would need a standard version in your setup in order to create a publisher.

For more info about different features in different editions, see: Features Supported by the Editions of SQL Server 2005[^]

The need to optimize rises from a bad design.My articles[^]

joey9363526-Jan-09 13:20

joey93635

26-Jan-09 13:20

I understand. In order to get full replication I have to have at least one publishing point (which has to come from at a minimum, a standarad version of SQL) and I also have to have one subscriber. Would the DB replicate on a specfic timed interval or when it detects that there has been changes? Thank you,
Joey

Re: SQL Replication Question Please be kind - Newbie here!

Wendelius26-Jan-09 18:12

Re: SQL Replication Question Please be kind - Newbie here!

26-Jan-09 18:12

In short: on a specfic timed interval. Replication uses SQL Server Agent jobs which are executed on an interval (configurable).

The need to optimize rises from a bad design.My articles[^]

joey9363527-Jan-09 8:55

joey93635

27-Jan-09 8:55

Mike, in your opinion, what type of bandwidth would we require for this type of replication to happen smoothly? The sites are linked together through an IPSec tunnel, however we are using a Cable Modem at one end (~3-5MBps down and no more than ~1MBps up) and the other end is 2 bonded T1 connections. I'm assuming that the replication will really only replicate the necessary changes, I'm just a little concerned about it becoming a bandwidth suck.
Thanks,
Joey

Re: SQL Replication Question Please be kind - Newbie here!

Wendelius27-Jan-09 9:52

27-Jan-09 9:52

Sounds like you need transactional replication. That replication works so that first a snapshot is taken from the source to get the current situation for the publication. This is delivered to subscriber(s). After that modifications to publication are gathered at the source and they are delivered to subscribers at configurable intervals.

Just a warning. This works fine when the transfer is only from source to target. If it's bi-directional so that the same data can be modified on all nodes, you will easily get into trouble because of update conflicts.

Finally to your question. The bandwith depends at least on these things:

replication interval, the smaller the interval is, the less modifications need to be transferred
amount of changes, how much data is changed (inserted, updated and deleted) at the source between two transfers
characteristics of the changed data, if it is mainly numbers or dates, it requires less bandwith than for example longer varchar data not to mention BLOB data
reliability of the connection, if the data must be sent several times, it will affect. Also it affects if the data is buffered on distributor because connection isn't available.

So as you see, it's quite impossible to give any accurate bandwith, but I believe that if you investigate those things, you'll get a clear picture on the data amounts.

Also why not build a test replication environment, replicate the actual data and use replication monitor in SQL Server and performance monitor to see what kind of amounts are transferred.

BTW, I noticed that you're new to CodeProject, welcome! Just to inform you that we have a voting system you can use if you want. Each reply can be marked good/bad and if the type of the post isn't reply, you'll see voting options in the lower right corner of the post from 1 (bad) to 5 (good). Usually these are used to indicate if the answers given to a person were helpful or not.

Mika

The need to optimize rises from a bad design.My articles[^]

a count query

sana1723-Jan-09 10:37

sana17

23-Jan-09 10:37

hello,
i have to ask for a sql query:

scenerio:
i have two tables CHATROOMS AND MEMBERS

CHATROOMS table contain columns (ROOM_ID(pk) and ROOM_NAME)
MEMBERS table contain columns (MEMBER_ID, ROOM_ID(fk))

now i have a gridview control in which i have to display all ROOM_IDs along with members init.

like:

ROOM_ID | MEMBERS
room1 | 5
room2 | 7
room3 | 6
room5 | 2

i want a single query for it coz i am binding data to gridview using SQLDATASOURCE control in ASP.net(C#)

the query i am trying is not working!
my query is:
select count(*) as total from MEMBERS where ROOM_ID = (select ROOM_ID from CHATROOMS)

the error on this query is logical that the inner query is returning multiple rows on which the outer WHERE is bound Frown | :(

please help me out i am struct in btw my project....

thanks,
tc
regards,
Sana

$@N@

Re: a count query

Wendelius23-Jan-09 10:44

23-Jan-09 10:44

Perhaps be something like:

select c.room_id, count(*)
from chatrooms c
inner join members m
on cm.room_id = c.room_id
group by c.room_id

The need to optimize rises from a bad design.My articles[^]

Re: a count query

sana1723-Jan-09 11:13

sana17

23-Jan-09 11:13

Thanksalot!!!
my problem is solved now..
Allah bless youuu!

tc
regards,
Sana

$@N@

Re: a count query

Wendelius23-Jan-09 11:15

How to modify a DataSet VB.NET

23-Jan-09 11:15

You're welcome Smile | :)

The need to optimize rises from a bad design.My articles[^]

enipla23-Jan-09 8:58

enipla

23-Jan-09 8:58

I have populated a dataset with a dataadapter and now I want to change the values. Nothing happens.

All rows are selected

 Dim tblADR_BASE As DataTable
 tblADR_BASE = dsADR_BASE.Tables("ADR_BASE")
 Dim rows() As DataRow = tblADR_BASE.Select()

 Dim intCRNO As Integer



 Dim i As Integer
 For i = 0 To rows.GetUpperBound(0)
     intCRNO = checkForCRNO(rows(i))
     rows(i)("dsp_CRNO") = intCRNO
     rows(i)("CITY_ID") = "test"

Console.WriteLine(rows(i)("dsp_CRNO"))

dsADR_BASE.AcceptChanges()

 Next i

Whats weird is I can wright the supposed changes to the console, but if I actually open the table in the dataset, nothing has been changed.

Am I missing some sort of save?

Thanks

Wendelius23-Jan-09 9:14

23-Jan-09 9:14

With a quick look the code looks fine (although you don't have to call AcceptChanges on every iteration). What does the code look like where you investigate if data is changed.

The need to optimize rises from a bad design.My articles[^]

enipla23-Jan-09 9:24

enipla

23-Jan-09 9:24

Thanks Mike,

Dim test = dsADR_BASE.HasChanges

Produces false.

I swear I had this working a week ago on a different table. I have since added fields to this table and think maybe that screwed things up. I have refreshed everything.

Wendelius23-Jan-09 9:29

23-Jan-09 9:29

It's because you call AcceptChanges in the loop. That method clears the modified flag from all rows. The idea behind AcceptChanges is that you let the rows to be modified (or inserted or updated) until you put the data to a safe place (for example database). After that the modification flags can be removed.

So in short, remove the AcceptChanges.

The need to optimize rises from a bad design.My articles[^]