Here is my code:
cn.Open()
cmd.CommandText = "insert into Student values('" ......
cmd.ExecuteNonQuery()
cn.Close()
After closing the connection I want my DataGridView to refresh it's data's also.
I am new in VB.NET I tried datagridview.refresh() but it's not working as I think it's like repainting not updating it's data's.
Thanks.
If you update the underlying business object, the UI should update automatically. My guess it that you forgot to do data binding, for example DataGridView.DataSource = yourDataTable.
EDIT: the easiest way from where you are right now would probably be to replace this:
cmd.ExecuteNonQuery()
with this:
Dim dt As New DataTable
dt.Load(cmd.ExecuteReader())
and then:
DataGridView.DataSource = dt
If you need database updates, you may want to use a DataAdapter and its Update method. The overload I linked is specifically for a DataTable, i.e. you don't need a DataSet, unless you have it already.
As #Neolisk said you have to do databinding .. for example
Dim ds as DataSet
Dim sSql As New OleDb.OleDbCommand
sSql = cnEZApp.CreateCommand()
cmd = New Data.OleDb.OleDbDataAdapter("SELECT * FROM student ORDER by kode", conn)
cmd.Fill(ds, "student")
dgvGuru.DataSource = ds.Tables("student")
So, to update table as datasource you have to do
sSql.CommandText = "insert into Student(...) values(...)"
cmd.UpdateCommand = sSql
cmd.UpdateCommand.ExecuteNonQuery()
cmd.ExecuteNonQuery()
Related
i was trying to insert record from one table to another using Data Set, first here's the code:
Try
Dim ds1 As New DataSet
Dim dbada2 As New OleDbDataAdapter
Dim dbbl2 As New OleDbCommandBuilder
Dim dbcon As OleDbConnection = New OleDbConnection(dbconstring)
dbcon.Open()
Dim cmd1 As OleDbCommand = New OleDbCommand("SELECT InspectionID, ICTDIR, UnitDescription, SizeType, QuantityNo, SerialNo FROM DeliveryInspection WHERE ICTDIR = #ictdir", dbcon)
cmd1.Parameters.AddWithValue("#ictdir", txtRefNo.Text)
Dim dbada1 As New OleDbDataAdapter(cmd1)
ds1.Clear()
dbada1.Fill(ds1)
dbcon.Close()
dbcon.Open()
dbada2 = New OleDbDataAdapter("SELECT * FROM LogSUF", dbcon)
dbada2.Update(ds1)
dbcon.Close()
Catch ex As Exception
MessageBox.Show(ex.ToString, "DBADA 2 Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
here i have 2 DataAdapters, The first one is from the table DeliveryInspection and the second is from LogSUF. both tables have the same Column with the only difference is that LogSUF has no records.
I want to make a system that will insert a record from DeliveryInspection (with the corresponding ICTDIR from the Text Box where the user typed it which is txtRefNo) to the LogSUF. My code doesn't have error but it doesn't work either and i tried some ways to fix this problem. Please help and also is there another way to do this? I'm a beginner.
When you call Update, only the rows with a RowState of Added, Modified or Deleted will be saved. As it stands, all your rows have a RowState of Unchanged, so there's nothing to save.
The solution is to set AcceptChangesDuringFill to False on the first data adapter, before you call Fill. That way, the AcceptChanges method is not called implicitly when you call Fill and each RowState will remain Added, ready for the row to be inserted when you call Update.
So I'm making a rota system for a project and I need a textbox to output the contracted hours of the employee that the user currently has selected in the combo box. The problem is, I have no idea how to go about it;
Sub GetContractedHours()
Dim sSql As String
Dim newds As New DataSet
Dim newdt As New DataTable
sSql = "SELECT emp_contractedhours FROM Employee WHERE emp_fn ='" & cboEmpName.Text & "%'"
Dim con As New SQLiteConnection(ConnectionString)
Dim cmd As New SQLiteCommand(sSql, con)
con.Open()
Dim da As New SQLiteDataAdapter(cmd)
da.Fill(newds, "Employee")
newdt = newds.Tables(0)
txtUserAlertHours.DataSource = newdt
con.Close()
End Sub
Please help! :)
You don't need any of that code. Just get all the data in the first place and then bind your ComboBox and your TextBox, e.g.
Dim table As New DataTable
Dim conection As New SQLiteConnection(ConnectionString)
Dim adapter As New SQLiteDataAdapter("SELECT emp_fn, emp_contractedhours FROM Employee", connection)
adapter.Fill(table)
cboEmpName.DisplayMember = "emp_fn"
cboEmpName.DataSource = table
txtUserAlertHours.DataBindings.Add("Text", table, "emp_contractedhours")
The TextBox will then be automatically populated when you make a selection in the ComboBox. That's how data-binding works.
If you do want to query the database each time then you shouldn't use a data adapter at all. You're only retrieving one value and that's exactly what ExecuteScalar is for. Create a command with the appropriate SQL, call ExecuteScalar and assign the result to the Text of your TextBox.
If you really did want to use data-binding with the code you have (which would be silly) then you can bind just as I have demonstrated above. Just note that, if you're going to use a different DataTable each time, you need to remove the old binding first. You can do that most easily by calling Clear on the DataBindings collection, assuming you have not bound any other properties.
I have some problems here. I need help.
Recently, I have created a local database called stock.mdf and the application will be getting all the data from the hosting MySQL database into this local SQL Server database.
I am using sqlBulkCopy to inserting all the data. I have tried to view it after inserting. But when I close my application, I head back to check the table data. It does not inserted. Why is that?
Here is my code:
Here will be retrieving the data from the hosting
Dim connStr As String = "server=xxxx;user=xxx;database=xxx;password=xxxx;"
Dim conn As New MySqlConnection(connStr)
Dim cmd As New MySqlCommand
Dim Adapter As New MySqlDataAdapter
Dim StockData As New DataTable
Try
Dim SQL As String = "SELECT * FROM stock"
Console.WriteLine("Connecting to MYSQL.....")
conn.Open()
cmd.Connection = conn
cmd.CommandText = SQL
Adapter.SelectCommand = cmd
Adapter.Fill(StockData)
' StockViewGrid.DataSource = StockData
Catch ex As Exception
Console.WriteLine(ex.ToString())
Finally
conn.Close()
Console.Write("Done")
End Try
This will be the places where sqlBulkCopy working:
As well, I am trying to view from the stock table.
Dim Local_connectionStr As String = "Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|stock.mdf;Integrated Security=True"
Dim Local_conn As New SqlConnection(Local_connectionStr)
Dim Local_cmd As New SqlCommand
Dim Local_Adapter As New SqlDataAdapter
Dim Local_StockData As New DataTable
Try
Using sqlBulkCopy As New SqlBulkCopy(Local_conn)
'Set the database table name
sqlBulkCopy.DestinationTableName = "stock"
'[OPTIONAL]: Map the DataTable columns with that of the database table
sqlBulkCopy.ColumnMappings.Add("stockId", "stockId")
sqlBulkCopy.ColumnMappings.Add("id_android", "id_android")
sqlBulkCopy.ColumnMappings.Add("itemCode", "itemCode")
sqlBulkCopy.ColumnMappings.Add("quantity", "quantity")
Local_conn.Open()
sqlBulkCopy.WriteToServer(StockData)
Local_conn.Close()
End Using
Catch ex As Exception
Console.WriteLine(ex.ToString())
Finally
Local_conn.Close()
Console.Write("Done")
End Try
Try
Dim SQL As String = "SELECT * FROM stock"
Console.WriteLine("Connecting to MYSQL.....")
Local_conn.Open()
Local_cmd.Connection = Local_conn
Local_cmd.CommandText = SQL
Local_Adapter.SelectCommand = Local_cmd
Local_Adapter.Fill(Local_StockData)
StockViewGrid.DataSource = Local_StockData
Catch ex As Exception
Console.WriteLine(ex.ToString())
Finally
Local_conn.Close()
Console.Write("Done")
End Try
Since I can't comment (not enough points) I will put my thoughts here. Can you check that you got the expected data with a
Console.WriteLine(StockData.Rows.Count.ToString)
Console.ReadLine()
Also, your destination table doesn't have a PK that is auto increment, does it?
Sorry about the comment as an answer. (Untested code)
Unfortunately your code extracts are lacking headers etc, so are not complete, and I cannot be absolutely certain, BUT in your retrieving routine you seem to be declaring StockData as a local variable. This means that, although this may well be being filled with the data from MySQL, it is immediately discarded on exiting from this routine. Therefore the StockData variable in the sqlBulkCopy routine will be empty, and therefore will insert nothing. You need to fix your scope and make sure that the StockData read from MySQL is the same StockData used in SqlBulkCopy.
I am attempting to populate items into a datagrid and then update them back into the database using 2 buttons (one loads, one will save) and a datagrid on a form. I keep running into "Syntax error (missing operator) in query expression" upon update and I am not sure why. Another question i have is where do my DataAdapter and Dataset need to be dimensioned in memory? Under the class?
'this loads my data from db into datagrid
Dim con As New OleDb.OleDbConnection
Dim sql As String
con.ConnectionString = "Provider=Microsoft.jet.oledb.4.0;data source=dbsrc.mdb"
con.Open()
sql = "SELECT * from [Employee Assignments]"
da = New OleDb.OleDbDataAdapter(sql, con)
da.Fill(ds, "Assignments")
con.Close()
DataGridView1.DataSource = ds.Tables("Assignments")
The following code should update my database to reflect changes made in the datagridview
'this will eventually update the datagrid back into the db
Dim cb As New OleDb.OleDbCommandBuilder(da)
Dim con As New OleDb.OleDbConnection
'Dim sql As String
con.ConnectionString = "Provider=Microsoft.jet.oledb.4.0;data source=dbsrc.mdb"
con.Open()
da.Update(ds, "Assignments")
con.Close()
DataGridView1.DataSource = ds.Tables("Assignments")
I read this artcle on msdn - http://msdn.microsoft.com/en-us/library/system.data.common.dataadapter.update.aspx - but it did not seem to help much, I am confused but I believe my problem is not identifying and passing the correct dataset back into the database. How should I deal with the dataset that I pull, modify, and then send back into the DB using the DataAdapter?
When a table contains spaces in its name you should inform the CommandBuilder about this problem
setting the QuotePrefix and QuoteSuffix property to avoid errors
cb.QuotePrefix = "["
cb.QuoteSuffix = "]"
The default for these twos is an empty string and thus, when you try to write your changes back to the database, you get a syntax error.
I am working in VB.NET and I have a simple requirement:
I have added a MDB file to a DataSet and it contains 21 tables.
I have a DataGridView and a ComboBox on my form.
I was able to get the ComboBox populated with the table names available in the DataSet by iterating through dataset.Tables.
Now I want to the user to be able to select the table name from the ComboBox and then populate the contents of that table.
I tried the following code:
Datagridview1.DataSource = dataset1
Datagridview1.DataMember = dataset1.tables(combobox1.selecteditem)
Datagridview1.Refresh()
But I only got the column headers. Then I read that I need a TableAdapter to populate the DataSet with that table. But if I use the TableAdapter then I won't be able to populate the table in a generic way.
Currently if I have to populate TableA then I will have to create an instance of Dataset1TableAdapters.TableA and then use it's .Fill property to populate the table. I will also have to use "Dataset1TableAdapters.TableB`. Is there a generic method to populate any table in the DataSet?
The following worked for me:
Datagridview1.DataSource = dataset1.tables(combobox1.selecteditem)
C# but easily convertible to VB.Net (I suppose):
String connectionString = #"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=""C:\test.mdb""";
String tableName = combobox1.SelectedItem.ToString();
String sqlSELECT = String.Format("select * from [{0}]", tableName);
System.Data.OleDb.OleDbDataAdapter da = new System.Data.OleDb.OleDbDataAdapter();
da.SelectCommand = new System.Data.OleDb.OleDbCommand(sqlSELECT, new System.Data.OleDb.OleDbConnection(connectionString));
DataGridView1.DataSource = dataSet1;
DataGridView1.DataMember = dataSet1.Tables(tableName);
da.Fill(dataSet1, tableName);
I was just sketching a proof that "it can be done in a generic way" to your problem, you should elaborate and maybe come with something more elegant (and safe).
Private Sub BindData()
With customersDataGridView
.AutoGenerateColumns = True
.DataSource = customersDataSet
.DataMember = "Customers"
End With
End Sub
Just to clarify this answer. For Future Reference.
Public Class Form1
Dim con As OleDbConnection = New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\test.accdb;")
Private Sub Button1_Click
Dim da As New OleDbDataAdapter
Dim table As String = ComboBox1.SelectedItem.ToString
Dim sql As String = String.Format("select * from [{0}]", table)
da.SelectCommand = New OleDbCommand(sql, con)
DataGridView1.DataSource = DataSet.Tables(table)
da.Fill(DataSet, table)
End Sub
End Class
Not trying to Ressurect, but i thought the working version of this VB Script should be posted.
I would like to point out that the dataset is held by Visual Studio, hence the strange source string.