"Frazer" <Ichor@hotmail.com> wrote in message
news:Oxy7FNvSEHA.3140@tk2msftngp13.phx.gbl...
> hi
> i have a combo box which i populate with all tables from northwind
database
> and when the user selects an item from the combo, i want to populate the
> datagrid with data from that table.
>
> private void FillComboBox()
>
> {
>
> DataSet allTablesDataSet = new DataSet("AllTables");
>
> string sqlString;
>
> this.tableComboBox.Items.Clear();
>
> sqlString = "Select * from sysobjects where type ='u'";
>
> this.sqlDataAdapter = new SqlDataAdapter();
>
> this.sqlDataAdapter.SelectCommand = new SqlCommand(sqlString,
> this.sqlConnection);
>
> this.sqlDataAdapter.Fill(allTablesDataSet,"AllTables");
>
> this.tableComboBox.DataSource = allTablesDataSet.Tables[0];
>
> this.tableComboBox.DisplayMember = "name";
>
> this.tableComboBox.ValueMember = "name";
>
> }
>
> private void OnTableComboBoxSelectedIndexChanged(object sender,
> System.EventArgs e)
>
> {
>
> if(this.tableComboBox.SelectedIndex == -1)
>
> return;
>
> this.tableDataSet = new DataSet();
>
> this.sqlDataAdapter.SelectCommand = new SqlCommand("Select * from [" +
> this.tableComboBox.SelectedValue + "]" ,this.sqlConnection);
>
> this.sqlDataAdapter.Fill(this.tableDataSet, "Table");
>
> this.dataGrid1.DataSource = this.tableDataSet;
>
> this.dataGrid1.DataMember = "Table";
>
> }
>
>
>
> however the first time when the program is run i get the foll error. how
do
> i resolve that?
>
> thnx
>
> An unhandled exception of type 'System.Data.SqlClient.SqlException'
occurred
> in system.data.dll
>
> Additional information: System error.
>
> on this line
>
> this.sqlDataAdapter.Fill(this.tableDataSet, "Table");
>
>

> parent, one for the child, and just set the bindings of the grid and the
> CombBox. You'll need to use a DataRelation
> http://www.knowdotnet.com/articles/datarelation.html to make this easy.
If
> you do this, you won't have to trap anything on SelectedIndexChanged to
get
> the child records to show up in a grid. "

"William Ryan eMVP" <dotnetguru@comcast.nospam.net> wrote in message
news:uXopm#0SEHA.3672@TK2MSFTNGP10.phx.gbl...
> Hi Frazier:
>
> Are you firing another query each time the index changes? you definitely
> don't want to do this. You can just load the data into a datatable and
bind
> it to the combobox. Also, you're getting a SQLException which means
> specifically it's a problem w/ the db.
>
> Cor is exaclty right about the SelectedIndexChange and that's ostensibly
> causing this even though it's a db error. Also, don't use Dynamic SQL,
use
> Parameters. Nonetheless, you'll want to grab two tables, one for the
> parent, one for the child, and just set the bindings of the grid and the
> CombBox. You'll need to use a DataRelation
> http://www.knowdotnet.com/articles/datarelation.html to make this easy.
If
> you do this, you won't have to trap anything on SelectedIndexChanged to
get
> the child records to show up in a grid. This is pretty common and if hit
a
> search engine for Master Detail ADO.NET there will be tons of examples.
>
> Let me know if you need any elaboration.
>
> HTH,
>
> Bill
>
> --
> W.G. Ryan MVP Windows - Embedded
>
> http://forums.devbuzz.com
> http://www.knowdotnet.com/dataaccess.html
> http://www.msmvps.com/williamryan/
> "Frazer" <Ichor@hotmail.com> wrote in message
> news:Oxy7FNvSEHA.3140@tk2msftngp13.phx.gbl...
> > hi
> > i have a combo box which i populate with all tables from northwind
> database
> > and when the user selects an item from the combo, i want to populate the
> > datagrid with data from that table.
> >
> > private void FillComboBox()
> >
> > {
> >
> > DataSet allTablesDataSet = new DataSet("AllTables");
> >
> > string sqlString;
> >
> > this.tableComboBox.Items.Clear();
> >
> > sqlString = "Select * from sysobjects where type ='u'";
> >
> > this.sqlDataAdapter = new SqlDataAdapter();
> >
> > this.sqlDataAdapter.SelectCommand = new SqlCommand(sqlString,
> > this.sqlConnection);
> >
> > this.sqlDataAdapter.Fill(allTablesDataSet,"AllTables");
> >
> > this.tableComboBox.DataSource = allTablesDataSet.Tables[0];
> >
> > this.tableComboBox.DisplayMember = "name";
> >
> > this.tableComboBox.ValueMember = "name";
> >
> > }
> >
> > private void OnTableComboBoxSelectedIndexChanged(object sender,
> > System.EventArgs e)
> >
> > {
> >
> > if(this.tableComboBox.SelectedIndex == -1)
> >
> > return;
> >
> > this.tableDataSet = new DataSet();
> >
> > this.sqlDataAdapter.SelectCommand = new SqlCommand("Select * from [" +
> > this.tableComboBox.SelectedValue + "]" ,this.sqlConnection);
> >
> > this.sqlDataAdapter.Fill(this.tableDataSet, "Table");
> >
> > this.dataGrid1.DataSource = this.tableDataSet;
> >
> > this.dataGrid1.DataMember = "Table";
> >
> > }
> >
> >
> >
> > however the first time when the program is run i get the foll error. how
> do
> > i resolve that?
> >
> > thnx
> >
> > An unhandled exception of type 'System.Data.SqlClient.SqlException'
> occurred
> > in system.data.dll
> >
> > Additional information: System error.
> >
> > on this line
> >
> > this.sqlDataAdapter.Fill(this.tableDataSet, "Table");
> >
> >
>
>