I want to know how to use the ASYNC CTP to manage the querying of a SQL Database with a SQL Select statement and use a SQLDataAdapter to fill in a DataSet. I have downloaded the VS2010 SP1 and the ASYNC CTP, I have also reviewed the videos on the MSDN site and the documentation included.
View 1 RepliesI am using vb2008 express edition and SQL Server 2000What I am trying to do is programmically populate a dataset with records from a database and then bind the fields to textbox controls so that and changes will be updated in the dataset and eventually the database.I have managed to get as far as displaying the data in a form, but cannot understand how to update the database when a button is clicked.
View 3 RepliesI'm still in my novice stages of .net development, and I think I may be trying to make something too complicated.In VB.Net 2008, I'm using a SQLDataAdapter to Fill a dataset with records being returned from a Stored Procedure (SQL Server 2005).I'm using that dataset as the datasource for a gridview. Up to this point, everything is great and I understand what's happening.I'm getting ready to make my first-ever attempt at updating the data in thegridview and then pushing the updates back to the SQL dB.Here's where I'mgettingconfused...to cut to the chase, what's the simplest way to load the updates back into SQLServer?
View 2 RepliesI have the following SQL:
[Code]...
I want to put it (the select count statement) in this LINQ statement so I can get the sales count in my linq statement: Dim TheLeads = (From L In DB.Leads Where L.IsDeleted = False Select L).ToList() Is this possible to do in LINQ?
A co-worker wants to convert the following IfThenElseIf statement into a Select Case statement.
Explain why this is not possible.
If temperature = 100 Then
X = 0
ElseIf population > 1000 Then
X = 1
ElseIf rate < .1 Then
X = -1
End If
I'm trying to write a 'developer friendly' wrapper for the Windows API EnumWindows - the problem is that the API uses a callback function that gets invoked on another thread, where as I want my wrapper function to simplify this and make it more useful by working like any other normal synchronous function and just returning a value.
Now if the API just called the callback once that would be fine, as I would just call the API and make the wrapper function wait until it got a signal from the callback function telling it to continue... but the API calls the callback function over 100 times (once for every window handle that exists). The biggest problem is that there is nothing that indicates that any particular call to this callback function is the last one, so my wrapper function has no idea when it is safe to continue and return the list of window handles to the caller.
The only solution I could think of is to do this:
1. The wrapper function calls the API and starts a timer that waits 2 seconds before it raises the Elapsed event. The wrapper function then pauses until it receives a signal (ManualResetEvent)
2. Each time the callback function is raised by the API on a different thread, it stops the timer (so this is before the 2 seconds have elapsed), adds the current window handle that was passed in by the API to the list of handles, then starts the timer again.
3. If the timer reaches its 2 second interval then it is assumed that we are at the end of the windows because otherwise the callback would have stopped the timer. So the timer's Elapsed event handler is what signals the original thread (that the wrapper function is executing on) to continue as we now have a complete list of windows to return.
This works fine and does exactly what I want... but I dont like it.
I dont like forcing the caller to wait an extra 2 seconds after the API has done its last callback but more importantly I dont like assuming that the API will never take longer than 2 seconds between callbacks. In reality on my PC it is never anywhere near that long between callbacks, it is something like 200 miliseconds, but I have no idea how long it would be on a slower PC and I want this to be completely reliable.
[URL]
have a table with following fields
Emp_id varchar(50)
Emp_Name varchar(50)
Emp_surname varchar(50)
[code].....
I need to use a SELECT statement to select all data under a column name (like all employee names) and then to add the values to a listbox.
I usderstand that the select statement must be:
"SELECT * FROM EmployeeTable WHERE EmployeeNames LIKE *" (at least I think)
but then what? combobox1.fill ("EmployeesTable") ?
I have a table which contains a list of products for a company. They input data about how much stock they have and also the level at which they want to be reminded that they need to order new stock.
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I want to list all the true results in a form which the user is then able to navigate through. What would be the best way to go about doing this?
I am returning to VB and coding after several years of trying to be out of coding :)
I would like in grabbing data retrieved from a SQL database call into an array of sorts so that I can quickly close the database connection. I am having some trouble remembering how to do this. Most of the posts I've found say to use the dataSet() functionality, but I do not have a table name for the structure to mimic. I am selecting from several tables on a remote server.
with the following code which gets stucked on the line of reader = Cmd.ExecuteReader(). It says the SqlException was unhandled (An expression of non-boolean type specified in a context where a condition is expected, near '7/2/2010'.)
[Code]...
I have successfuly connected to a database and have create a select statement (with access) which works most of the time except when im trying to perform a where statement with a date:
strEmployeeDepartmentLocation = Application.StartupPath
con.ConnectionString = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source = " & strEmployeeDepartmentLocation & "swineFlu.mdb"
strSQLSelectQuery2 = "SELECT NumberOfCase FROM table1 WHERE Date = 21/04/2009;"
i dont no if im writing it in the wrong format or what but it dont seem to bring back any data
my program is "live" and my customer has troubles because it doesn't functioning as well as it should.I don't know what happen, did I changed something or not but suddenly data won't save to database from newly created forms. Beside this form I have additional 20 forms and everything is working like a charm and I use same code logic to save data to database. I tried to find myself what could be the reason, check by entering data directly to database table (works fine), check insert statement of dataset table (seems fine, too) and everything I could imagine. But now I ran out of ideas and I had to ask here.
Also, I added 3 fields to database table (nvarchar, int and decimal). All 3 of them allow nulls. I changed dataset and data entry form and now data won't insert if I dont enter values to int and decimal fields. Also, this decimal field doesn't accept 0 value if enter but if I assign value 0 from the code than it is ok. I'm not sure if I somehow changed concurrency and somewhere. I tried to find where I can change it but I couldn't find it. I use Visual Studio 2008 and Sql Server 2005 Express. Language vb.net.
I've only dealt with firing a single SQL statement at a SQLServer table and returning a single result... easy....
however....
is there a way to fire a dual sql command and load the results into respective tables within a dataset?.. I'm thinking something along these lines (this code of course does not work)
Dim ds As New DataSet
Dim dt1 As DataTable = ds.Tables(0)
Dim dt2 As DataTable = ds.Tables(1)
[Code]....
I am trying to work programmatically with a dataset. The tableAdapter was created by dragging and dropping the dataset on my form, and then deleting the binding navigator and dataviewgrid. The problem I am having is when I am trying to delete a record that is DBNull. The dataset.delete( ) call creates fields for each of the fields, along with their data type (say Description as String). but I get an error whenever the field has a DBNull value.
CourseTableAdapter.Delete(DBDataSet.Course.Item(1).CourseID, DBDataSet.Course.Item(1).CourseDescription)
The error is Throw New Global.System.Data.StrongTypingException("The value for column 'Description' in table 'Course' is DBNull."I do have Option Strict On, but the problem exists even if I turn it off.
I have a datatable and I would like to get the MAX number from this table where Term Number (first Column) is a certain value. If my datatable is declared as dtMyTable, I'm assuming I need to use dtMyTable.Select(), but I'm not sure if this is the best way.
View 2 RepliesI'm using Vb2005 and Db MS access Is it possible to use tow Select in same sql Statement like this example:
Code:
"Select....Select......."
I have 2 dropdown lists, 1 label & 1 textbox.on selection of 'product categories' @ 1st ddl, 2nd ddl displays all product categories.question is, how may i display the product category id @ the label, and name @ the textbox, on load/selection of 2nd ddl?[code]....
View 3 RepliesIf I have a datatable with 5000 rows for example can I do a select statement by row numbers. like paging throught it so I don't have to display all 5000 in the datagrid.. i want to go forward and back by 100 rows
vb.net 2008 (vs 2008)
For example:
dgInbox.DataSource = dsInbox.Tables("Inbox").select(between rows 200 and 300)
I have a sql statement
SQL = "select * from Candidate where test_date = " & TextBox2.Text
I am getting error in the line myDataAdapter.Fill(myDataSet)
Conversion failed when converting the varchar value '03/15/11' to data type int
In my sql server test_date column data type is varchar.
I am tryin to access a 2003 Microsoft Access Database using VB in an OleDb format. The database file name is Billings.mdb and there are 3 tables in the file the one I am trying to access is tbl Clients. When debugging the program I continue to get an Unhandled error point to the FROM part of the SELECT statement. It continues to occur regardless of my attempts to vary the input.
In the program my connection statement is as follows:
Dim connectionString As String = "Provider = Microsoft.Jet.OleDb.4.0; Data Source = C:Documents and SettingsTrialsBillings.mdb"
The Select statement is as follows:
Dim selectStatement As String = "SELECT ID, ..., PB " & "FROM tbl_Clients " & "WHERE ID = ?sngID"
Basically, I have the following sql select statement in vb.net.[code]...
From the above statement, I would like retrieve several data and the count of Traceid from trn_Invt_Details where the traceid in trn_Invt_Details match with traceid in trn_Invt. By the way, it will also based on the criteria where the field of ErrorType in Trn_Invt_Details is Null or contain empty string. Then it will retrieve out the count of traceid.Finally, all the results will save to dataset in vb.net
What's wrong with this ?
ERROR: Type mismatch in expression.
conectare_db()
data_table = New DataTable[code].....
I just replaced a different segment of code with the select case statement and it works fine. However I don't understand what the dim is for after you do "Select case [variable name here]"
I currently just dimmed a value as nothing. I didn't specify any data type for my variable I'm using for this case statement. But it works.[code]...
I am using vb.net 2005. I am trying to select data from a table where the field [hoteldate] is 2 days from now. The field's format is MM/dd/YYYY and when I use the Where clause :WHERE HOTELDATE = DATEADD([DAY], 2, GETDATE()) it returns nothing. I am assuming it's because the getdate() function returns something like 2012-24-02 T blah blah. How do I convert so I can get a match? I've tried several things including converting do a
View 4 RepliesI have a simple vb script which extracts some data from our accounting software to a text file. It works fine when I do not use a variable in my select statment as follows:
xselect = "SELECT SourceJournal,JournalRegisterNo, PostingDate, PostingComment,UserCreatedKey
FROM GL_DetailPosting
[Code].....
I have a select statement, this select statement comes back on a slqadapter, would l would like to do is like
textbox1.text=sqladapter.(columane1)
textbox2.text=sqladapter.(columane2)
and so forth instead of filling a datagrid.
I'm using the following statement to search an Excel file. It specifies Sheet1$ and I would like to do a search that included another 12 sheets. Is there syntax that allows a search across several sheets?
View 13 RepliesI was using an If block to see if a line in a file contained a specific string. But I need to look for many different string and do different things based on each. So I don't want a million nested If blocks. So I decided to use a Select statement. But, I can't figure out how to use .Contains with it. If I do .ToLower.Contains, like I did in the If block, it stops me.
VB.NET
For Each _line In lineList Select Case _line.ToLower
[code].....
I know i must use Stored Procedures as much as Possible, but i would like to know the following.
A: Can i get a SQL Injection attack from a SELECT statement such as (Select * from MyTable) ?
B: Also, can i get a SQL Injection attack when I use the SQLDataSource in ASP.NET?