C# linq to sql error - C# Discussion Boards

Re: MySql is not listed in data source part!

sina rafati nia5-Feb-13 22:49

sina rafati nia

5-Feb-13 22:49

sorry your link doesn't load !
what is data provider??

Re: MySql is not listed in data source part!

Dave Kreskowiak6-Feb-13 1:48

Dave Kreskowiak

6-Feb-13 1:48

The link works just fine.

As for "what is a data provider?", read this[^]

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Re: MySql is not listed in data source part!

sina rafati nia6-Feb-13 19:14

sina rafati nia

6-Feb-13 19:14

yeah thats right it works! but the problem is I dont know what to do now!! Is there any easier way??

Propagating a MySQL Database Transaction Rollback through WCF using MSMQ

Ger Hayden4-Feb-13 21:44

Ger Hayden

4-Feb-13 21:44

When my clients have to make changes to their database, a MySQL transaction is commenced.

In time it is either committed or rolled back. Rollbacks happen in error scnarios and critically by user choice.

I am following Juval Lowy's method of implementing transactions with a view to picking up the ambient MySQL transaction being managed by the client.

So the client enteres a new row, WCF / MSMQ relays it to a service that calls another service and makes a database update - nothing is committed yet.

But the user has a change of mind - and hits Rollback rather than commit.

The row is rolled back on the client, but the remote update is committed.

Is what I am attempting techincally possible?

Ger

Re: Propagating a MySQL Database Transaction Rollback through WCF using MSMQ

Pete O'Hanlon4-Feb-13 22:18

Pete O'Hanlon

4-Feb-13 22:18

What you are after is technically possible - as long as the TransactionScope hasn't finished, the transaction can be rolled back by the user. Rather than the Lowy examples, I find them to miss out on some critical details and concentrate on less important bits, I would recommend this[^] article and this[^] blog post which cover it in a lot more depth.

I was brought up to respect my elders. I don't respect many people nowadays.

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Re: Propagating a MySQL Database Transaction Rollback through WCF using MSMQ

Ger Hayden4-Feb-13 22:47

Ger Hayden

4-Feb-13 22:47

Pete, we are on the same hymn sheet with Lowy - I printed those two articles off a couple of weeks back and read them then. I'll be lining them up beside my code when I get back to it this evening to see what I can flush out.

Ger

To get the info for how to validate an embedded object in office files

Learning_to_code4-Feb-13 19:54

Learning_to_code

4-Feb-13 19:54

I have a component developed in C# ( chain of responsibility pattern) which validates the file types based on the extension and signature mismatch.
It is good to go with the files like doc,docx,xls,xlsx. But for the scenario where an object(say another word,xlsx) is embedded in the file to be uploaded how to extract and validate that file.
This component also validates a zip file by extracting it to a path and doing the checks for all,one by one.
Any pointers for how to do this for an embedded object as I couldn’t find any blog also.
p.S:
Thanks in Advance
Avinash
http://www.garykessler.net/library/file_sigs.html[^]

C# linq to sql error

dcof4-Feb-13 12:32

dcof

4-Feb-13 12:32

In a C# 2008 desktop application, I have the following statement that give when an error when the code points to a different database:

 eRPTDataContext rptDataaddRVW = new eRPTDataContext();
 var eRPTaddRVW = (from a in rptDataaddRVW.eRPT_Transaction_Trackings
                   where a.Package_ID == packageId
                   select a).FirstOrDefault();

Here is the error message I get:
2013-02-04 16:13:15.3731|ERROR|erptsampleclient.eRPTSample|Error Processing --> Specified cast is not valid.
2013-02-04 16:13:15.3731|ERROR|erptsampleclient.eRPTSample|************* Stack Trace *******************
2013-02-04 16:13:15.3887|ERROR|erptsampleclient.eRPTSample|   at System.Data.Linq.SqlClient.SqlProvider.Execute(Expression query, QueryInfo queryInfo, IObjectReaderFactory factory, Object[] parentArgs, Object[] userArgs, ICompiledSubQuery[] subQueries, Object lastResult)
   at System.Data.Linq.SqlClient.SqlProvider.ExecuteAll(Expression query, QueryInfo[] queryInfos, IObjectReaderFactory factory, Object[] userArguments, ICompiledSubQuery[] subQueries)
   at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query)
   at System.Data.Linq.DataQuery`1.System.Linq.IQueryProvider.Execute[S](Expression expression)
   at System.Linq.Queryable.SingleOrDefault[TSource](IQueryable`1 source)
   at erptsampleclient.eRPTSample.addNewReviewPackage() in C:\_svn\Cas_client\erptsampleclient\eRPTSample.cs:line 1308
2013-02-04 16:13:15.3887|ERROR|erptsampleclient.eRPTSample|Error Processing --> Specified cast is not valid.
2013-02-04 16:13:15.3887|ERROR|erptsampleclient.eRPTSample|************* Stack Trace *******************
2013-02-04 16:13:15.4043|ERROR|erptsampleclient.eRPTSample|   at erptsampleclient.eRPTSample.addNewReviewPackage() in C:\_svn\Cas_client\erptsampleclient\eRPTSample.cs:line 1369
   at erptsampleclient.eRPTSample.Main(String[] args) in C:\_svn\Cas_client\erptsampleclient\eRPTSample.cs:line 154
2013-02-04 16:13:23.3135|INFO|erptsampleclient.eRPTSample|******************ADD (CREATE) REVIEW (RVW) (METHOD 2 CALL)**********************
2013-02-04 16:13:28.8359|INFO|erptsample.ERPTProxy|The number of attachments in the list are ->1
2013-02-04 16:13:54.2171|INFO|erptsample.ERPTProxy|add review package successfully for rvw pkg id: RVW0204201300524 return code = 0
2013-02-04 16:13:58.5227|INFO|erptsampleclient.eRPTSample|Review Package was created successfully for Package id: RVW0204201300524
2013-02-04 16:13:58.5695|ERROR|erptsampleclient.eRPTSample|Error Processing --> Specified cast is not valid.
2013-02-04 16:13:58.5695|ERROR|erptsampleclient.eRPTSample|************* Stack Trace *******************
2013-02-04 16:13:58.5851|ERROR|erptsampleclient.eRPTSample|   at System.Data.Linq.SqlClient.SqlProvider.Execute(Expression query, QueryInfo queryInfo, IObjectReaderFactory factory, Object[] parentArgs, Object[] userArgs, ICompiledSubQuery[] subQueries, Object lastResult)
   at System.Data.Linq.SqlClient.SqlProvider.ExecuteAll(Expression query, QueryInfo[] queryInfos, IObjectReaderFactory factory, Object[] userArguments, ICompiledSubQuery[] subQueries)
   at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query)
   at System.Data.Linq.DataQuery`1.System.Linq.IQueryProvider.Execute[S](Expression expression)
   at System.Linq.Queryable.SingleOrDefault[TSource](IQueryable`1 source)

When I change the code to the following:

var eRPTaddRVW = (from a in rptDataaddRVW.eRPT_Transaction_Trackings
                   where a.Package_ID == packageId
                   select new { erptPackageID = a.Package_ID, erptFileLocation = a.File_Location }).FirstOrDefault();
M

I do not get an error.
The problem is I want to be able to update the database row I just accessed and the linq will not compile clean to let me do that.

I am getting the follwowing error message when I try to access a specific field:
Error 10 'object' does not contain a definition for 'erptFileLocation' and no extension method 'erptFileLocation' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?) C:\_svn\Cas_client\erptsampleclient\eRPTSample.cs 1320 56 ERPTsampleclient
Here is the code I am trying to add:

    if (eRPTaddRVW != null)
       {
         eRPTaddRVW.erptFileLocation = RVWFile; // save location of original spreadshgeet
         rptDataaddRVW.SubmitChanges();
}

Can you tell me what I can do to solve my problem?

Re: C# linq to sql error

Simon_Whale4-Feb-13 12:59

Simon_Whale

4-Feb-13 12:59

dcof wrote:
2013-02-04 16:13:15.3887|ERROR|erptsampleclient.eRPTSample|Error Processing --> Specified cast is not valid.

this line of the stack trace shows that you have a conversion problem from the database into the table, I would make sure that your property types are set correctly

dcof wrote:
var eRPTaddRVW = (from a in rptDataaddRVW.eRPT_Transaction_Trackings
where a.Package_ID == packageId
select new { erptPackageID = a.Package_ID, erptFileLocation = a.File_Location }).FirstOrDefault();

if you put a watch on the eRPTaddRVW and then expand the results do you see any results? or do you see empty properties?

Lobster Thermidor aux crevettes with a Mornay sauce, served in a Provençale manner with shallots and aubergines, garnished with truffle pate, brandy and a fried egg on top and Spam - Monty Python Spam Sketch

Re: C# linq to sql error

dcof4-Feb-13 16:22

dcof

4-Feb-13 16:22

The following is empty:erptFileLocation = a.File_Location.

I want to update the value of the field called File_Location.

Can you tell me how to rewrite the following statement so that it will let me update the File_Location field. It's property is read-only.

Stepper motor control by using Fez mini

Member 98108984-Feb-13 12:22

Member 9810898

4-Feb-13 12:22

Hi,
Can anyone guide me how to write the code for digital outputs for stepper motor. I just want to run motor clockwise and to do 4 rotations and then I want it to rotate counter clockwise and to do four anti-clockwise rotations. I am using Fez mini and for driver, I am using IFR530 MOSFET circuit.

Re: Stepper motor control by using Fez mini

OriginalGriff5-Feb-13 1:24

OriginalGriff

5-Feb-13 1:24

Not from that little we can't.
We have no idea what interface circuitry you have between the PC and the IRF530 (I assume you miss-typed) - you certainly can't connect one of them directly to a standard PC output!

If you get an email telling you that you can catch Swine Flu from tinned pork then just delete it. It's Spam.

Re: Stepper motor control by using Fez mini

Member 98108985-Feb-13 1:46

Member 9810898

5-Feb-13 1:46

Ok, I will try to explain my circuit. I have 4 IFR530, which are going to the unipolar stepper motor. These 4 MOSFETs are connected to Digital I/Os of FEz Mini (MCU) via optoisolators and some resistors. So I have to Program the FEZ mini to run the stepper motor.

Re: Stepper motor control by using Fez mini

OriginalGriff5-Feb-13 1:53

OriginalGriff

5-Feb-13 1:53

And what does this have to do with C#?

If you get an email telling you that you can catch Swine Flu from tinned pork then just delete it. It's Spam.

Re: Stepper motor control by using Fez mini

Member 98108985-Feb-13 1:58

Member 9810898

5-Feb-13 1:58

It is only C# which can be used for FEZ mini(microcontroller) and without programming Fez mini won't work. I am using c# because I want to control the rotaion and direction of motor.

Re: Stepper motor control by using Fez mini

Dave Kreskowiak5-Feb-13 2:36

Dave Kreskowiak

5-Feb-13 2:36

Why are you posting this here instead of the Forums at GHI, where the FEZ comes from??

http://www.tinyclr.com/forum[^]

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Re: Stepper motor control by using Fez mini

Member 98108985-Feb-13 2:49

Member 9810898

5-Feb-13 2:49

I thought someone here might know anything about c#?

Re: Stepper motor control by using Fez mini

Pete O'Hanlon5-Feb-13 4:21

Pete O'Hanlon

5-Feb-13 4:21

It's not the C# that's the problem though, is it?

I was brought up to respect my elders. I don't respect many people nowadays.

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Re: Stepper motor control by using Fez mini

Member 98108985-Feb-13 13:06

Member 9810898

5-Feb-13 13:06

The problem is I don't know C# programming that is what I need help with.

Re: Stepper motor control by using Fez mini

Dave Kreskowiak5-Feb-13 5:12

Dave Kreskowiak

5-Feb-13 5:12

C# is just the language to tell the FEZ board HOW to do something. Your question is more about WHAT to tell the FEZ, which we really can't help you with.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

how to make a movable button in c#

mortezakazemi684-Feb-13 4:24

mortezakazemi68

4-Feb-13 4:24

how to i can create a movable button in c#

Re: how to make a movable button in c#

Pete O'Hanlon4-Feb-13 4:59

Pete O'Hanlon

4-Feb-13 4:59

Write code to change the X and Y coordinates as appropriate.

I was brought up to respect my elders. I don't respect many people nowadays.

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier