I am fairly inexperienced with using datatables in VB. My question is this: Can I access a particular column of a table by name if it is not defined elsewhere like when I populate a datatable using sqldataadapter.
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Is this the way it can be done? I believe this is the case, but can't find any definitive examples online (probably not searching properly)
Is there a simple way to assign a populated datatable's columns to another empty datatable? That is, I want to copy a datatable's structure only but not its data.
View 6 RepliesI use SqlDataAdapter.Fill to retrieve data from a SQL2000 Server, and the datatable is updatable.
Recently, we plan to upgrade to SQL2005, during testing we found that the same statement will return a datatable, which is readonly We need to change the column's readonly property in order to update it.
Ok so this is going to take some explaining. The process I am trying to do is grab data from a table function in SQL and then fill a dataset with the returned values. I then have to run this query twice more to query an alternative number table. Then add to the same table as the previous queries.This needs to be as fast as possible, so I am currently using an adapter.fill to populate the datasets and then a dataset.merge to put them all into one table.
The problem is the query can return duplicates which waste time and space, because of this I made column 3(part_ID) the primary key to stop duplicates.When this is run with the .merge it quits at the first instance of a duplication and doesn't continue with the population.
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i defined a list of DataTables
Dim PreSubTables As New List(Of DataTable)()
Then I parse some source files and depending on the data, possibly none of the tables in the list PreSubTables2 might be populated, so it's just an empty list. Later on when i refer to the first table in the list , I get "index out of range error"
If (PreSubTables(0).Rows.Count > 0) Then ...
' just dealing with the first table: PreSubtables(0)
For ii = 0 To (PreSubTables(0).Rows.Count - 1)
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I'm just trying to come up with a line that checks whether the(at least the first)Table in the list is populated, before I can print it out or do other things.
I'm having some trouble trying to export a datatable to Access. I've built an Access DB and Table identical to the datatable that I'm trying to export using ADOX.Now using and OLEDB connection I'm trying to populate that table. The following code works just fine in another app written in 2005 but not in 2008 for some reason.
Basically I'm bringing in the empty Access table into a dataset.Filling that table with the rows from the export datatable.Then running the dataadapter's update method to send the data to Access.The problem is the da_a.Update doesn't seem to work. No errors, the Access table just isn't being populated. I checked my before and after counts. I know that the datatable is being populated. It's just not landing in Access.
Dim conn_a As New OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & strFullFileName)
conn_a.Open()
'Select Access Table into new Dataset[code]....
VB2008 & mysql
Is it possible?
If so how?
Wanting to have multiple datagridviews showing unique information (via filters?) based on cell content all coming from one data table.
Example:
3 datagridviews accessing the same datatable that has a [Job Status] column limited to one of the following 3 entries NEW, JOBS IN PROGRESS or COMPLETED and having that column hidden from view on all gridviews
Top grid showing only NEW jobs
Middle grid showing only JOBS IN PROGRESS
Bottom grid showing only COMPLETED jobs
In a combobox populated by a DataTable I am having two issues!The SelectedIndex property will not set 1. Either by integer 2. Or by FindString
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[code]....First of all, when using "Using", is the Open() method required? Some I've seen with, some without. Pretty sure it worked in both cases. Also, I've seen some that end with the Close() method before the End Using.Is that necessary? Basically, when is Open() needed, when is Close() needed, and why is Using/End Using needed at all?
**EDIT: For some reason the "Insert Code Block" isn't working properly at colouring the code.
I've done an internet search to determine if I can detail if a SQLDataAdapter is empty after running an SQLCommand? My research so far point I can't check if the SQL dataAdapter is empty until I bind it to a dataset/datatable. Ideally would not like to run another SQL command to do a row count to determine if query retruns rows or not. I'm populating a datagridview and would like to alert the user that there is no data to view. What's the most efficent way to check if an SQLDataAdapter is empty?
View 4 RepliesI'm not even sure what I'm asking is even possible, but here goes:
Is there a way to loop through a sqlDataAdapter to find multiple tables?
Currently I have a module that you pass in an object and it automatically fills the parameters of a stored procedure with the values of the object. It works great, except when the stored procedure returns more than one table, it only returns the first one.
Here is what I tried to get to that second table:
Dim ds As New DataSet
Dim table As New DataTable
Dim reader As SqlDataReader = command.ExecuteReader
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I have the followin problem. Opening a table using SqlDataAdapter, numeric columns(sqlDbType = int16, 32, 64) that allow Null value, are set in my dataRows to 0.I am using Visual Studio 2010 and Sql Server 2008.Here's my code:
Dim cmd As New SqlCommand
Dim ds As New DataSet
Dim dt As DataTable
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At the following cmd.ExecuteNonQuery() line, I get the following error message: [code] I have followed the example at page [code] as closely as possible, but it does not work.Additionally, I am not sure of the syntax for the length (64) that I have for the BigInt or if it should even have a length.All of the examples that I have found in MSDN uses only parameters with character rather than numberic type. [code]
View 6 RepliesI'm moving over date.oledb commands to SQL ones and wondering what the equivalent to executenonquery here is? This is what I have at the moment and I can bind select queries to datagrids no problem how would I get the DBCommand to execute the query?
Dim DBConn As SqlConnection
Dim DBCommand As SqlDataAdapter
Dim DSPageData As New DataSet
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I have an empty table loaded to the datagridview. I add a new row to the table by
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This code works fine, if i add a new row to the table in which some rows already exists. (Works only when after inputing data to the new row I select any another row). But when I use this code for the first row in a table, it creates a new empty record in the database. The data I have inputed into the datagirfview fields aren`t saved.
I am having trouble inserting data to a DB using a dataadapter. Here is the code:
Dim daDevices As New SqlDataAdapter(sql, MyConnObj)
Dim dsDevices As New DataSet("WORKSHOP")
daDevices.FillSchema(dsDevices, SchemaType.Source, "Replacements")
daDevices.Fill(dsDevices, "Replacements")
Dim tblDevcies As DataTable
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I fill a dataset using fill() method of sqldataadapter. The select query call a user defined function in it. My problem is that when I run this query in sqlDataAdapter , the fill() method take about 70 Sec. to give output but if I run the same query in Enterprise Manager or in Query Analyzer it gives output within a 1 or 2 Sec.
View 2 RepliesI recently discover that running something like : Dim Da = New SqlClient.SqlDataAdapter( "TRUNCATE TABLE MyTable", connection) will create an empty SqlDateAdapter but it still execute the command. I want to prevent this kind of use ( drop, update, or even systable use,...) and allow my SqlDateAdapter to execute SELECT command only. I can't use a storing procedure because the command must be editable by the website users. After some research i found this :
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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 trying to check for concurrency when updating a record in the database. Here is my current VB.NET code and Stored Procedure code to do the update.
When a user changes a Status column value the DataGridView CellValidating event is fired and in that event it try's to update the record in the database using the stored procedure. The update works, but my SqlDataAdapter doesn't update dtmUpdateDatetime in dtResults. My UpdateDatabase function uses dtmUpdateDatetime to check for concurrency.
Public Class frmCalculatedResults
Private dtCriteria As New DataTable
Private bs As New BindingSource
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i want to put multiple instances of sqldataadapter into a single transaction. how can i accomplish this?
View 2 RepliesI am porting VB.Net 2 code (VS 2005) to VB.Net 4 (VS 2010). So far things have been going relatively smooth. However, in testing my new ported code, I came across a strange behavior. In VS 2005 (.Net 2), I have a DataTable filled with data. I then use a DataAdapter to send updates back to the SQL Server. When I perform the qlClient.SqlDataAdapter.Update() command, it execute in roughly 4 seconds. The same code,on the same table in VS 2010 (.Net 4) runs in 1 Minute 17 Seconds. This is completely unacceptable. However, I have no clue as to why it is happening. The .Update() method is an internal command, not one that I modified in any way. It does not error out, it's just painfully slow.
View 1 RepliesI'm trying to figure out why my adapter is not updating my SQL database table. I have a form with 3 data grid views on it. If the user changes the display index, width, or visible properties of the columns I want to save their settings. For some reason the adapters update runs without error, but when I check the database table nothing is updated, why? Does it have something to do with the TableMappings?
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I 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 have a big stored procedure that I run. At the end its supposed to select a singe value to say if it succeeded or not, so I run the query as
Dim Command As New SqlCommand(SqlString, Conn)
Return Command.ExecuteScalar()
Which works. However there is an error in my stored procedure. I know its causing an error because the logic in the stored procedure rolls back the transactions, and after the Execute Scalar call, my transaction count is down to 0 and the my data hasn't changed. However no SQL exception was generated.
The strange part is, I changed the code to grab all the result sets from the SP to see if I could get more information. So I called the same SP like this,
Dim DAObj As SqlDataAdapter = New SqlDataAdapter
Dim CommandObj As SqlCommand = New SqlCommand(SQLString, Conn)
DAObj.SelectCommand = CommandObj
Dim DS As New DataSet()
DAObj.Fill(DS)
When I run this, with the exact same sql as before, executing the exact same stored procedure, this time I get an SQL exception because one of my nested SP calls was missing required parameters. So what could cause this? Why would running it one way produce an error and the other way have the error but not report it? Is the difference on purpose, or some kind of obscure bug in ADO.Net?
I'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 a circumstance where I'm popping up a dialog window containing a "Please Wait" message, running an SQL query, then replacing the "Please Wait" message with a DataGridView containing the collected results.The code I'm using for this is basically:
Dim X As New Data.SqlClient.SqlCommand
X.CommandText = "SELECT some_data FROM someTable"
Dim XAdapter As New System.Data.SqlClient.SqlDataAdapter(X)
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I would like to put the retrieval of this data into a background thread, so that the UI doesn't freeze up while I'm loading larger datasets, but, having done this, I'd also like to allow the user to cancel and close the dialog, if accessing the data takes longer than they want to wait.At the moment, this Dialog window can take some arbitrary SQL string and display the results (using SQLDataAdapter) without any extra code.How can I make this process interruptible, while also retaining the ease of access of the SQLDataAdapter?
I Fill a DataTable using a SQLDataAdapter then use a BindingSource as my DataGridViews DataSource. My DataGridView contains a ComboBoxColumn named "Status". There are two ways to update the Status column. One, the user can change the value by clicking a cell in the column then the combobox appears and they make their selection. Second, the user can click a button on the form and the Status for all the visible rows are changed to "Exported". I use a stored procedure as my adapters Update command.
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I have a combo box and onload I want the combobox to be populated with data in a field from the database. However, when I execute I receive an empty combo box please could someone look what am doing wrong..
Private Sub populatecmbprojtype()
Dim cmd As New SqlCommand
Dim conn As SqlConnection = GetDbConnection()
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I am having a strang problem with button event handlers that I am creating at runtime.Actually if I set the form as startup form everything is working fine but when I set the main apllication form as startup form the events for buttons created at runtime are not firing.I am posting the code so that you can have a better look and see whts wrong?I have two classes under spotlight here "Class1" and "Grid"I am creating an instance of grid in class 1 and in a sub in grid I am creating buttons dynamically as follows and adding event handlers
For i As Integer = lIndex To uIndex
Dim btn As New Button
btn.Name = ds.Tables(tblName).Rows(i)(btnName).ToString
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