Sample Table
Job_ID Job_Name Status
1 TEST00001 FOR KE
2 TEST00002 FOR KE
[code]....
I have sql query that will get a jobname where status is equal to 'FOR KE' and I have multiple users that will query that.Now, what if two queries was executed at the same time? Will the two users get the same jobname? How can I avoid that?
I am writing a message system on my server, the xml is something like this
<xml>
<entry>
<sender>[code]....
my problem now i guess is 2 fold, i wish to combine the first 3 queries into a single query and place in a list or a collection or is there a way to do this with a single query that will give me my desired result?
I am using VB.NET 2008 and SQL Server 2008.My program runs the below query all the time for different values, but yesterday, this query was executed, and it set the other values correctly in myTbl, but it didn't set the "Status" column to 'C' as stated in the query.
update myTbl set [Floor] = 'a',FloorConf = 'C',Status = 'C' where [myUpdateCol] = 'a-1'
There is no error when executing the query.Why the "Status" column wasn't being set correctly, and what can cause this ?
m_cmdSQL = New SqlClient.SqlCommand
With m_cmdSQL
.Connection = adoCon
.CommandText = "update myTbl set [Floor] = 'a',FloorConf = 'C',Status = 'C' where [myUpdateCol] = 'a-1'
End With
m_cmdSQL.ExecuteNonQuery()
I have some pieces of code like this:
strSoftware = "select MobileSoftware.Entertainment, MobileSoftware.MobileApplication, MobileSoftware.RingingTone, MobileSoftware.Directory from MobileSoftware where MobileName = '" + strName + cmdSoftware = New SqlCommand(strSoftware, con)
drSoftware = cmdSoftware.ExecuteReader
When I write the query in one line, then it works. But when I do like this:
[Code]...
I'm trying to run a transaction and I'm having some issues. What would cause a query to be executed before the transaction.commit() is called? Is there a specifice order that queries should be ran when working with a transaction? I have 1 update query that will always execute no matter what, before the .commit() is called. [code]
View 4 RepliesHow do you query a Dataset with SQL queries? I'm using VB with Visual Studio 2005. I've got a large library of SQL queries I'd like to run in-memory on a Dataset.All the examples in the documentation show how to "query a dataset with code," but none show how to run a simple SQL query against a dataset. I've seen other threads that say you can do so, but no code examples. Can anyone provide sample code to show how you would run a simple SQL "Select..." query (using the same syntax you would use to query a database) on an in-memory dataset?
View 3 RepliesThe documentation for an API I am using explicitly says that I need to call close() on an object when I am done with it. I would also like to log something there.I understand GC, might not happen at expected time, etc. etc. I still want to implement some code at cleanup.I read that I need to Override Finalize() to do this.I wrote a console app to test and it looks like it indeed works.However, this does not work with windows forms. I put a break point and it never gets hit in the Finalize method.How do you add some code to be executed at cleanup time for a window form?Here is my console app test:
Public Class Foo
Public Sub New()
Console.WriteLine("In Foo Constructor")[code]......
I know something like this exists, I juts don't know the right word to search about it, so basically I have a cosole application and if it runs twice it crashes. I wanna dispay a message: Sorry app alerady running.I can look at processes and see if my exe is there already running but that's much harder.
View 2 RepliesI am working on a Data Survey Project and first I have a few questions about the different types of databases, and second, I need help querying my tables that have relationships.
1. I need a database that is stand alone. It is just the back end for the program. Simply to hold all the data an employee gets while out on a job. So would I be better using access, or SQL Express? I have played with both, but I do not want a large redistribution to my user machines. When I compile and produce this app does the SQL Database still work without installing any SQL Technology? Or do they have to go in after they install my app, and install Express?
2.Overview: I suppose depending on the first question regarding the database, it might change this question a bit, but none the less...I have 4 tables( using Access at the moment) I will be generating Reports based on data in the database. I haven't gotten that far yet. *Project* is the table that holds all the details that pertain to the job and client. It has a "one-to-many" relationship to *Survey*. So for one customer there are going to be many Survey Records. *Project Type* also has a 1-to-many back to *Projects*. Parts is kind of an orphan, but is linked to the *Survey* table with a one to many. So there can be many parts for one survey. I wanted this table for a drop down box, so the user could just simply select what hardware he was using instead of typing all the names and parts.
So in VS 2008 using the Designers and related Query tools, how do I constrain the Survey Data to one Customer? I have one form that opens from a button that is "New Project" and then there are all the *project* fields listed, so the user fills out the info and hits accept and that opens a new form called "frmSurvey" I need to add some code to the accept button to check what type of project is selected from the frmNewProject and then run a select query based on that. How do I write query statements in the code section of the form, without using the Visual Database tools?
Ill stop here, and get these questions out of the way first. If I could just get a handle on how to use the data properly with different forms and different controls with my queries, that would be great.
DATABASE
CODE:
I built a prototype system with some database queries. Since it was just a prototype and I was very new to databases, I just used a direct string. This is the string I used and it works fine:
command = New OleDbCommand("SELECT * FROM " + prefix + "CanonicForms WHERE Type=1 AND Canonic_Form='" + item + "'", dictionary_connection)
Now, in putting it in a real system, I wanted to use the more secure parametized method, so after some googling I came up with this:
command = New OleDbCommand("SELECT * FROM @prefix WHERE Type=1 AND Canonic_Form=@form", dictionary_connection)
command.Parameters.AddWithValue("@prefix", prefix + "CanonicForms")
command.Parameters.AddWithValue("@form", item)
But all I get is an error for an incomplete query clause. What have I done differently between the two?
I used to write this:
Private Sub Example()
Static CachedPeople As List(Of MyApp.Person)
If CachedPeople Is Nothing Then
[code]....
But then wondered if I could reduce this to:
Private Sub Example()
Static CachedPeople As New List(Of MyApp.Person)
...rest of code...
End Sub
will the "New" bit only be executed once when the function is first executed but in the next call, it will already exist.
I know that LINQ queries are deferred and only executed when the query is enumerated, but I'm having trouble figuring out exactly when that happens.Certainly in a For Each loop, the query would be enumerated.What's the rule of thumb to follow? I don't want to accidentally enumerate over my query twice if it's a huge result.
For example, does System.Linq.Enumerable.First enumerate over the whole query? I ask for performance reasons. I want to pass a LINQ result set to an ASP.NET MVC view, and I also want to pass the First element separately. Enumerating over the results twice would be painful.It would be great to turn on some kind of flag that alerts me each time a LINQ query is enumerated. That way I could catch scenarios when I accidentally enumerate twice.
I had one problem when query in VB.net. It fails at first time after SQL server restart, the fail message is "timeout expired". The same query success in second time onward, How can I set timeout in VB dataSet property? I use DataSet to communicate with database. Below is the query statement I used in FillBy() function.
[Code]..
As the title describes I am looking for a way to query for the UTC time from NTP/SNTP Servers from 'VB.NET'The only libraries I have found for VB.NET to such tasks appear require a fairly large sum of different forms of currency.
View 1 RepliesNo Update to DB?? ***?
[code]
And why isn't there a query to just INSERT a whole record at a time, based on a DataSource, or is that a better kept secret than what REALLY happened during the final hours of the Titanic?
Also, I'm under the impression that the default CommandType is Text.
I have this query which I want to submit after the user click a button.
Update tbl_books Set Bk_Rent = Bk_Rent - 1 Bk_Avl = Bk_Avl + 1 Where Bk_Id = ( Select * from tbl_transactions where Trans_Id = @a )
The problem is as far as I know, Update and Select queries have different formats. Update statements will use the ExecuteNonQuery()while Select needs a dataset. My problem is how can I execute these two statements at the same time. I tried this code but it didn't work out.
Dim command4 As New OleDb.OleDbCommand
Dim adapter4 As New OleDb.OleDbDataAdapter
Dim dataset As New DataSet
[Code].....
I have a datatimepicker1 on the form and want to display the result dataset in the datagrid view.So I use query builder in the dataset designer to put "@PickDate" in the filter of PickupDate.And i use the following code to get the result and show in datagrid.But it is not working.Actually I don't know what syntax to use for the date parameter.
Private Sub DateTimePicker1_ValueChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DateTimePicker1.ValueChanged
Me.HisPickupTableAdapter.FillByDate(Me.HisPickUpDataSet.HisPickup, Me.DateTimePicker1.Value.Date)
End Sub
I have an untyped dataset returned from my WebService. The user wants to dynamically construct a query referencing tables and columns and specifying values to test for.I have looked at Lambda Expressions and the Expressions.Expression Namespace. I think these provide the answer I'm looking for, but I'm not certain how to go about contructing the linq expressions to extract the datarows I'm looking for.
I plan on limiting the result to one datatable that the query will result in and i"ll provide the joins from the user's constructs.For a simple example I have a DataTable with (n) rows called "Table", and in it there is a computed column called "b_IsActive" that has the expression "Convert(IsActive, 'System.Boolean')". The user wants to retrieve all rows in "Table" where field "b_IsActive" is true.
I've created an SQL Query using the query builder. In the query builder, you can test the query by clicking the button "Execute Query", and entering the desired values in the parameter fields.
My query returns the correct results when I do this, but when I seemingly pass the same values at runtime, I get 0 records returned.The query is designed such that you can pass nulls if you don't wish to filter data by that particular parameter.
SQL Query:
SELECT ID, UPC, Quantity, Manufacturer, Style, Color, Size, Category, DateReceived, Cost, OriginalRetail, Retail, LocationID
FROM Inventory
WHERE (UPC = @UPC OR
[code]....
In the query builder "Execute Query" dialog, I enter a value I know that the db contains in the "Size" field, "1/1/1900" & "1/1/2199" in Dates A & B, respectively, and nulls for all other fields. This returns 1 record, which is just as I expected. It works correctly.But when I pass the same values into the method created by the designer, I get 0 records returned. I can't figure out where the problem lies. Even if I enter nulls for all fields other than the dates, it returns 0. This tells me that the dates are causing the problem, but I can't figure out why, because I'm passing strings equivalent to what I entered in the query builder.
I have this situation where I have a SqlDatasource control and the select query is like:
SELECT col1, col2 FROM table1 WHERE colDate = @date
The source of @date is a label with the text: 2009-05-29 12:06:00 I get the following error when I run the query:
Conversion failed when converting date and/or time from character string
I tried using convert(datetime, @date), as well as different date/time formatting of the label itself. Everytime I get the error.
However, when I run the query in the management studio like:
SELECT col1, col2 FROM table1 WHERE colDate = '2009-05-29 12:06:00'
I found out that the @date is parsed as 05-29-2009 01:30:00 TT I don't know where the TT is coming from? And I'm sure SQL Server wouldn't be able to handle it?
we are using Punch Machine for Attendance with zkemkeeper.dll and geting AttLog using Vs.net 2010.How can Get Records from SQL Query? my table structure like this
LogID int P.K.
DeviceIP varchar
EnrollNo int
[Code]....
In a VB.Net application, how can I either: Find the dropDownList selectedIndex position of something just added to a database.Have a form restart with the most recently-added entry showing in the DropDownList, by way of modifying the inline SQL query to display by date/time added
View 3 RepliesMy problem is that some code I enter will not be executed. Here is an example of my Form Load event. If i debug the code then the first two lines are executed. The MsgBox won't be executed though. or anything else after it. My programm does run perfectly. But i cant make any changes anymore It's driving me nuts, I don't have the faintest Idea what could be wrong. I sent the code to a friend and he isn't having any problems at all. We both use win7 64bit (he has ultimate, i have home) [code]
View 2 RepliesI am developing a window application. I'm using Visual Studio 2005 and Mysql Database. The problem is, only one form is getting executed when I try to debug.I have changed the startup form to other forms(from a list of existing forms), but still that same old form is getting executed, even if I delete that form or exclude it from the project, it still keeps on executing.
Where this form is stored?(I deleted it from the folder where all other forms exist)
For intOuterCount = 1 to 5
For intInnerCount = 1 to 4
intTotalCount +=1
Next
Next
Here is the code:
Function getData(ByVal id As String)
Dim reader As SqlClient.SqlDataReader
Dim statement As String
[code].....
Possible Duplicate: Convert Null to zero in access databaseI'm using Microsoft Visual Web Developer 2010 Express to create ASP/VB.NET page to connect with a Microsoft office Access 07. Here's my issue:
View 2 RepliesI want to open a website, change its javascript, then show the website + execute my changed js.
1) Is this possible?
2) How is this possible? ( VB.net, C#, FF + Addons )
EDIT: To your better understanding, I just want the js to be just changed for my browser output!
I have a hashtable of a class that contains a timer. When this timer elapses x amount of time, it calls a subroutine within the class. This subroutine calls several other functions and subroutines and then its done until the timer elapses again. Now one of the subroutines updates a label on the form and i can see that happening when its supposed to. There is another subroutine that should be updating another label but it is not. I believe this would be a simple correction but when i set a debug point on the routine it does not work. I'm not going to post the code for this as it is hundreds of lines of code and its probably just a configuration in the IDE that got changed somehow.
I run break points around the rest of the project just fine, even in other classes that use timers. Does anyone else have this problem of code being executed but not being able to debug it?
I have a project with 2 forms. I need the code to be executed on one form first, which is why it is run first, then I want to hide it and just display the user interface form. I have the following code, it makes both forms appear, but I only want the user display form to show: [code] I call both these subs in the frmLoad of the Processing form.
View 3 Replies