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hey can somebody suggest me any good sites with databases tutorials. i don't know anything about them. I don't know how they work, and what are tables, primary keys, tuples etc.
so i want to know about how databases work before getting into any sort of ms sql, mysql, oracle etc...
if you can recommend any book i'll appreciate it. by the way i'll be using ms sql server 2005 express edition, if that helps suggesting
ty
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SQL Course Here[^]
And Here[^]
And, just for your info, some free cheat sheets Here[^].
modified 1-Aug-19 21:02pm.
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didn't you read my post? i asked of databases tutorials not sql, although it doesn't matters if they are also teaching what are databases besides sql
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Instead of complaining about the sources I gave, why on earth didn't you just do a google search. It really isn't that hard unless nobody has taken the trouble to teach you how to "Google" 
To save you the trouble of finding somebody to teach you how to Google, just click this link and Google will return a list of web sites for you to investigate. "Database Tutorials"[^]
Relational Database Theory was listed on the second reference I gave. Perhaps it is you who should learn to read
modified 1-Aug-19 21:02pm.
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sorry didn't meant to be rude, and btw i searched for it on the google and whatever sources you gave aren't what i was looking for.
but thanks 
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Hi everybody.
I'm more of a c# kinda guy so not all that well up with the hard core sql stuff.
The problem I have is I have recently uninstalled all instances of SQL Server off my machine. Then I installed SQL Server 2005, and found that my web applications which relied on SQL express stopped working 
So I went to microsoft, and downloaded Express 2005 which did not do the trick. (it tells me it cant start up a user instance)
Anyhoo, this upset me somewhat, and as much as I play about with permissions and settings for express I just can't get it working. So, I think it would be better to ship all my .MDF files into real sql server which would be better anyway, but I cant find how to do this...
Please can somebody help???? Is it actually possible???
Thanks in advance. (sorry about the rambling story...)
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Hi,
Unsy wrote: it tells me it cant start up a user instance
Have you had a look ath this: http://msdn.microsoft.com/en-us/library/ms143684(SQL.90).aspx[^]. If I remember correctly, user instanes aren't allowed by default, so you may need to use sp_configure to change the setting.
Unsy wrote: , I think it would be better to ship all my .MDF files into real sql server which would be better anyway, but I cant find how to do this...
That's possible. Basically SQL Server Standard and Express Editions have the same codebase. Express has just some limitations.
I'm just wondering why you use user instances. User instance is run in the users account who makes the connection. You could also use normal instance and have the database running all the time and your web application could connect to that. It could make things simpler (administration, backups etc)
Mika
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Hi Mika
Thank you for your help. I have fixed my problem by simply attaching the MDF files to SQL 2005 which gives me the usual SQL server control and its on constantly.
Thanks again... 
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You're welcome 
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This should be simple, but I'm stuck.
I'm trying to use an SqlDataReader to populate a datagrid, but I get an error saying the reader does not produce a value.
But it does. I can wite the values to the console with this code
While reader.Read()
Console.WriteLine(String.Format("{0}, {1}", _
reader(0), reader(1)))
End While
The reader DOES produce values.
This code is where I ge the "reader does not produce a value"-
reader.Read()
DataGridView1.DataSource = PermitsPlusDataSet.ADR_BASE.Load(reader)
What do I need to do to get the DataGrid to recognize the values in the reader?
Thanks
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What happens if you take out the reader.Read() row. SqlDataReader is a forward only stream, so if you read the rows, the load method is unable to rewind to the start of the stream.
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Thanks, but same error when I remove reader.read()
"Expersion does not produce a value"
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The problem is most likely in the reader or the datatable (ADR_BASE) which is filled using the reader. I suspect that this has nothing to do with the DataGridView. The problem is reported on that row because on the same code row you Load the datatable and also assign the datasource.
However, could you post the code before DataGridView1.DataSource = PermitsPlusDataSet.ADR_BASE.Load(reader). It may reveal the source of the problem.
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You bet -
Dim queryString As String = "SELECT * FROM dbo.ADR_BASE;"
Using connection As New SqlConnection("Data Source=DEVBOX;Initial Catalog=PermitsPlus;Persist Security Info=True;User ID=*****;Password=*****")
Dim command As New SqlCommand(queryString, connection)
connection.Open()
Dim reader As SqlDataReader = command.ExecuteReader()
DataGridView1.DataSource = PermitsPlusDataSet.ADR_BASE.Load(reader)
I also checked to see if the reader has rows and it does.
Thanks, this is driving me nuts.
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Okay,
At a glance I don't see anything special, but since the datatable is already existsng, perhaps it's schema is incompatible. What if you try the following (there may be typos):
Dim queryString As String = "SELECT * FROM dbo.ADR_BASE;"
Using connection As New SqlConnection("Data Source=DEVBOX;Initial Catalog=PermitsPlus;Persist Security Info=True;User ID=*****;Password=*****")
Dim command As New SqlCommand(queryString, connection)
connection.Open()
Dim reader As SqlDataReader = command.ExecuteReader()
Dim tempTable As new System.Data.DataTable("ADR_BASE")
tempTable.Load(reader)
DataGridView1.DataSource = tempTable
'PermitsPlusDataSet.ADR_BASE.Load(reader)
'DataGridView1.DataSource = PermitsPlusDataSet.ADR_BASE.Load(reader)
do you still have error and if you do, does it occur on the Load row?
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Very interesting....
It worked. Sort of.
After the grid is populated, if I pan across the different columns, I get an error "System.ArgumentException: Parameter not valid. Apparently I have a datatype it doesn't like.
I'll dig around in the table and look for something strange. I can't really tell what column it's failing on. I'll try some other tables too.
I really want to thank you for you quick responses. I think this Forum is going to be a great help to me.
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enipla wrote: if I pan across the different columns, I get an error "System.ArgumentException: Parameter not valid. Apparently I have a datatype it doesn't like.
Or a datatype mismatch between the datatable column and the column in the datagridview.
Also check the pre-existing schema on the ADR_BASE datatable. Just a wild guess, but if you populate it somewhere with another tables data, it could lead to problems like this.
enipla wrote: I really want to thank you for you quick responses
No problem, glad if it helped 
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The Customer Specified and Suggested this configuration. I do not have to do it that way as long as is completely free and NoLicenses are requires. The end user must have the ability to retrieve data from the LocalDatabase at any time. The Database must be updated locally after each use or run and must all be available globally to the other 11 local machines (tester) or a master or supervisor machine (Tester) MASTER1 which is updated with all the other 11 localMachines (Testers) as well as its own local data. All records must be updated after each Machine (Tester) Cycle or the Next time that the machine (tester) is turned on it needs to update accordingly. Backups will be done locally on each machine at some specified frequency defined by the customer. Each machine has its own Unique Results and 1 Master or allMust have the others information avalaible to them to Query. I have the Database Created in MS Access for the first machine Tester) but the Customer will not accept it because it Requires Office or Licensing to be installed on 12 PC Platforms. SQL Server Express 208 willnot allow you to import a Database from MS Access and Save it as a SQLServer Express 2008 Database. Hope you can help.
Regards
BC
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BobClarkSQL wrote: The Customer Specified and Suggested this configuration. I do not have to do it that way as long as is completely free and NoLicenses are requires
So, do you have an option to use only one cenralized database?
Also is the network reliable all the time (this question actually included in the previous) or do you have to prepare for network failures? Since you have testers, I take it that information from the test run must reliably saved.
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As long as it is free and each local machine can get its local results as well as all the other 11 platforms data and Query each other and it is fre and seamless to the end user it really doesn't matter. It does not have to be fast it just need to be reliable and accurate. Any strategy that can accomplish this for fre is acceptable as long as local and master results can be received from each local machine.
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But in that case, the question is only in data modeling. Create a single database and the necessary tables. In those tables record the tester name (or whatever is the way you separate them). This way everyon can have own results as ell as they can use others results.
For example, if you have a table Measurement, it could have columns like:
- MeasurementID, int, primary key, not null
- Tester, int, not null, reference to Tester table
- MeasurementTime, datetime, not null
- MeasurementType, varchar(100), not null
- MeasurementResult, int, not null etc.
So when fetching results from a single tester you would restrict the query to only single Tester. But if you want to use other tseters, just modify the WHERE-clause.
And what comes to the database, you can use Sql Server 2008 Express Edition. Just not that Express edition has these limitations:
- 1 CPU
- 1 GB memory
- 4 GB of data per database
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Hi everybody,
I've just switched to VB .NET 2008 from MS Access 2007
I'm working as an applications developer for a number of companies. I make programs that access big databases through the Internet (by big, I mean a large number of rows)
In Access, connecting through the internet was so smooth since it reads only the current record while allowing searching, filtering, updating, etc...
When I used VB .NET, I found that the dataset is filled with all the records up on loading the form, and this would make the program extremely slow (it will take 10minutes+ to start!!!)
I read about using a datareader, but, does the datareader allow full sorting, updating, and filtering just like the dataset?
In a simple sentence, how can I implement the same data access model of MS Access?
Thank you.
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The idea is a bit different than in Access. You use for example SqlCommand in which you set the statement for your query. In that statement you restrict the rows you want to fetch i.e. you have a WHERE clause. DataReader is intended just to read the data what SqlCommand retrieves.
I suggest that you get familiar with the ADO.NET concepts. You could start for example here: Introduction to Data Access with ADO.NET[^] and Retrieving and Modifying Data in ADO.NET[^].
With a little bit of reading I'm sure you'll easily discover how powerful the whole ADO.NET is compared to Access for example.
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Thank you for your reply
First, I've no doubt that ADO .NET is much better than MS Access
But, the only thing that I want to implement is that to make my program read only the record that I'm viewing currently on the form (or may be read no more than 5 records in order to decrease the number of reads to the database server).
What's the easiest method for implementing this?
BTW, using the SqlCommand while limiting the number of records is not the thing that I want, for example, if I use it to read 10 rows only, then only those rows will be displayed in the form, and this is not correct in my case...
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