I have a .Net dataset and am adding a row to a table. This works and the record is saved to the database. How do I get the updated version of my row after the insert. Or, alternatively, how do I know the ID of the item that was added (so that I can then use it in a subsequent child table insert.
MyDataSet.ProjectRow r = dsMyDataSet.Projects.AddProjectRow(txtTitle.Text);
m_daProjects.Update(dsMyDataSet.Projects);
// What is the ID of the new item here?
If the column is an identity column you can find the new ID's in the inserted rows.
You: "thanks. which object maintains a list of inserted rows?"
You can use DataTable.GetChanges(DataRowState.Added) to get a DataTable with all DataRows which are going to be added. You need to use it before AcceptChanges was called. If i remember correctly TableAdapter.Update calls AcceptChanges at the end. Then you need to use it before m_daProjects.Update(dsMyDataSet.Projects):
DataTable addedRows = ds.modModel.GetChanges(DataRowState.Added);
MyDataSet.ProjectRow r = dsMyDataSet.Projects.AddProjectRow(txtTitle.Text);
m_daProjects.Update(dsMyDataSet.Projects);
now addedRows contains all DataRows with the new identity value in each row
foreach(DataRow addedRow in addedRows.Rows)
Console.WriteLine("New ID: {0}", addedRow.Field<int>("IdColumn"));
Update: However, in your case it's simpler. You have already the single row that you want to insert. So you dont need to call DataTable.GetChanges at all.
You can see the new identity value in the (typed DataRow) ProjectRow r after Update.
Thanks to Tim Schmelter. In the link he posted there's a reference to an article on Beth Massi's blog with a complete walkthrough of the solution. It worked for me.
http://blogs.msdn.com/bethmassi/archive/2009/05/14/using-tableadapters-to-insert-related-data-into-an-ms-access-database.aspx
The basic steps are:
1) Add RowUpdated event handler on the strongly typed table adapter. This event handler issues a new OleDBCommand to the database to retrieve ##Identity and then assigns the integer to the member column of the table.
public void _adapter_RowUpdated(dynamic sender, System.Data.OleDb.OleDbRowUpdatedEventArgs e)
{
HMUI.Classes.AccessIDHelper.SetPrimaryKey(this.Connection, e);
}
public static void SetPrimaryKey(OleDbConnection trans, OleDbRowUpdatedEventArgs e)
{
if (e.Status == System.Data.UpdateStatus.Continue && e.StatementType == System.Data.StatementType.Insert)
{
if (pk != null)
{
OleDbCommand cmdGetIdentity = new OleDbCommand("SELECT ##IDENTITY", trans);
// Execute the post-update query to fetch new ##Identity
e.Row.Table.Columns[pk(0)] = Convert.ToInt32(cmdGetIdentity.ExecuteScalar());
e.Row.AcceptChanges();
}
}
}
2) In the constructor of the form using the dataset and table adapter I attach the function in step 1 to the RowUpdated event on the table adapter's internal data adapter.
// Event to handle inserted records and retrieve the primary key ID
m_daDataSources.Adapter.RowUpdated += new System.Data.OleDb.OleDbRowUpdatedEventHandler(m_daDataSources._adapter_RowUpdated);
Related
My situation involves batch updates to individual tables in an SQLite database through ADO.NET objects. I use the DataAdapter.Update() method to push the changes which works well:
DataTable changes = dataset.Tables[table].GetChanges();
if (changes == null) return 0;
SQLiteCommandBuilder scb = new SQLiteCommandBuilder(adapter);
scb.ConflictOption = ConflictOption.CompareRowVersion;
int cnt = adapter.Update(changes);
return cnt;
However each time a record is inserted I also want the local DataSet tables to reflect with the newly inserted row id. For this I use the adapter_RowUpdated event :
static void adapter_RowUpdated(object sender,
System.Data.Common.RowUpdatedEventArgs e)
{
if (e.StatementType == StatementType.Insert)
{
SQLiteCommand cmd = new SQLiteCommand("select last_insert_rowid();", conn);
e.Row["id"] = cmd.ExecuteScalar();
}
}
The above fetches last_insert_rowid() because I'm able to see it when I debug by putting a breakpoint. However, the assignment statement to e.Row["id"] isn't working. The id change isn't reflected in my original DataSet and DataTable objects. For example when I test the following value (N refers to the specific row index), it still has a DBNull value. What is going wrong here? How can I ensure that the specific row which just got inserted is updated with its corresponding id field value?
dataset.Tables["projects"].row[N]["id"];
After a little experimenting, I found the solution to this myself.
As strange as it may sound but it looks like adapter.Update() requires a dataset along with the actual table name in order for this to work. I was passing the table object (DataTable.GetChanges()) so far which did the job of updating the database but failed only in this particular scenario. The moment I did that, the inserted id started reflecting in rows all over the dataset!
//int cnt = adapter.Update(changes); // doesn't work
int cnt = adapter.Update(dataset, tableName); // works perfectly!
edit
Lo and Behold! It even works when I just pass the table like this instead of entire dataset. It was only causing problem when I was just passing the changes table (got from dataset.Tables[tableName].GetChanges()).
int cnt = adapter.Update(dataset.Tables[tableName]); // works perfectly!
I am trying to save a new added row in a DataGridView to a database. I can't understand which method to call - either gridview1_UserAddedRow or gridview1_RowsAdded (what if it's just one row?).. So far, I've seen that gridview1_RowsAdded executes every time when the form loads.
The DataGridView is bound using a BindingList.
This is how the gridview1_UserAddedRow looks like:
private void dataGridView1_UserAddedRow(object sender, DataGridViewRowEventArgs e)
{
int lastRow = dataGridView1.Rows.Count - 2;
DataGridViewRow newRow = dataGridView1.Rows[lastRow];
bindinglist.Add(new MyTestClass{ ScheduleId = scheduleId, Name = Convert.ToString(newRow.Cells["Name"].Value),
Value = Convert.ToString(newRow.Cells["Value"].Value), TestId = testId});
}
Unfortunately, this doesn't work and nothing is inserted. Actually, I think this event is called when a new row is clicked. How else can I insert the newly created row in the database?
The code is not updating anything to the database as there is no code to update it.
You need to execute a query to update those new values. You could try using Commands:
http://msdn.microsoft.com/en-us/library/aa984369(v=vs.71).aspx
Or change the list to a DataTable, which allows you to update the values 'automatically' (a bit harder): http://msdn.microsoft.com/en-us/library/z1z2bkx2(v=vs.110).aspx
I would stay away form databinding, but if you can't, you can try this:
// Create a new row
DataRow dr = YourDataSet.Vendors.NewRow(); // Change 'Vendors' with your database table's name
// Add some data to your new row
dr[0] = 124;
// Insert the previous row
YourDataSet.Vendors.Rows.InsertAt(dr, 1); // Change the 1 to your index where you want to insert the data.
I have a DataGridView with a bit column which shows as a checkbox. The column is "IsDefault" by name, implying that if this cell is checked, all other cells in this column in the DataTable should be unchecked (only 1 cell in this column is allowed to be the default).
I managed to get this behaviour working by handling the change in CellContentClick event of the DataGridView, i.e.:
private void ViewIconsDataGrid_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
if (e.RowIndex == -1 || e.ColumnIndex == -1)
return;
DataTable table = ViewIconsDataGrid.DataSource as DataTable;
DataGridViewCell cell = ViewIconsDataGrid.Rows[e.RowIndex].Cells[e.ColumnIndex];
Guid rowID = (Guid)ViewIconsDataGrid.Rows[e.RowIndex].Cells["ID"].Value;
if (cell.GetType() == typeof(DataGridViewCheckBoxCell))
{
DataGridViewCheckBoxCell checkBoxCell = cell as DataGridViewCheckBoxCell;
bool value = (bool)checkBoxCell.EditedFormattedValue, previous = (bool)checkBoxCell.Value;
if (value != previous)
{
if (value == true)
{
Guid currentDefault;
if(MyIcons.Defaults.TryGetValue(MyGroupID, out currentDefault))
{
DataRow [] rows = table.Select("ID = '" + currentDefault.ToString() + "'");
if(rows.Length == 1)
{
rows[0]["IsDefault"] = false;
}
}
}
ViewIconsDataGrid.EndEdit(); table.AcceptChanges();
}
}
}
Now, clearly I'm trying to make changes to two records in the same DataTable here. The first I'm hoping the DataGridView changes (when the user changes the state of the checkbox) and then I'm doing another change on the DataTable to uncheck whichever row already had the check, hoping that will propagate up to the DataGridView. I need to commit both changes to the database of course.
Here's my database "update" code, which is kind-of generic, i.e. I pass in a select query for the whole table and a data table to update against:
using (SqlConnection connection = new SqlConnection(ConfigurationManager.AppSettings["Connection"]))
{
connection.Open();
using (SqlDataAdapter adapter = new SqlDataAdapter(MyQuery, connection))
{
adapter.InsertCommand = new SqlCommandBuilder(adapter).GetInsertCommand();
adapter.DeleteCommand = new SqlCommandBuilder(adapter).GetDeleteCommand();
adapter.UpdateCommand = new SqlCommandBuilder(adapter).GetUpdateCommand();
adapter.Update(MyTable);
}
}
So, the problem is that I get an exception when I try to update the table after making these changes: "Concurrency violation: the UpdateCommand affected 0 of the expected 1 records.". If there is no existing default, just a single record gets updated and all is fine.
Can anyone spot my mistake, or see an easier way for me to do this?
Edit 1: In the above fragment, MyQuery looks like this:
#"SELECT * From Picture WHERE ID_Group = '{0}' AND Deleted = 0 ORDER BY Created DESC
{0} is the guid of the group of pictures I'm updating, i.e. a select query gives all records in the Pictures table which are members of that group.
The call to AcceptChanges changes the RowState of every row in the table to Unchanged.
The subsequent call to DataAdatper.Update(table) doesn't find anything to update/insert or delete.
You need to call the Update on user input (like a click on a Save button )
EDIT To complete this answer with the findings below from #Robinson
You could raise the RowChanged event for the table handling the CurrentCellDirtyStateChanged event and manually commit the edit on the DataGridView. Otherwise the RowChanged event is raised when the row lost focus.
There are two problems here:
First, DataGridView events don't send to cache the changes correctly, you must use an other event, like a button click, to force DataGridView to cache the changes.
The other problem "concurrency violation" its caused by inserting a new row in a table with an Identity column (usually the primary key). I suggest use another button for inserts and force the new identity value in the DataGridView.
Whene you updates, i suggest to make deletes first, and next make the updates:
// First process deletes.
da.Update(dt.Select(null, null, DataViewRowState.Deleted));
// Next process updates.
da.Update(dt.Select(null, null, DataViewRowState.ModifiedCurrent));
This test code is really straightforward
var addedRows1 = (securityDataTable.GetChanges(DataRowState.Added));
MessageBox.Show(addedRows1.Rows[1].RowState.ToString());
MessageBox.Show(addedRows1.Rows.Count.ToString());
addedRows1.Rows[1].AcceptChanges();
var addedRows2 = (securityDataTable.GetChanges(DataRowState.Added));
MessageBox.Show(addedRows2.Rows[1].RowState.ToString());
MessageBox.Show(addedRows2.Rows.Count.ToString());
The 4 MessageBox show, in order, the following messages:
Added
3
Added
3
I would expect the count to return 2 on the last message. Why isn't that the case and can this be fixed by any mean? Note: The DataTable is not linked to a table nor a particular data source.
EDIT: Note that the RowState is ok (set to Unchanged) if I don't requery the GetChanges() the second time
GetChanges returns a copy of the rows. Are you using a data adapter to fill your data table? MSDN recommends calling AcceptChanges on the DataAdapter'
private void UpdateDataTable(DataTable table,
OleDbDataAdapter myDataAdapter)
{
DataTable xDataTable = table.GetChanges();
// Check the DataTable for errors.
if (xDataTable.HasErrors)
{
// Insert code to resolve errors.
}
// After fixing errors, update the database with the DataAdapter
myDataAdapter.Update(xDataTable);
}
Edit
Since you are just using a datatable, you could create a query for the rows that are added and call AcceptChanges on that row:
DataRow[] addedRows = datatable.Select(null, null, DataViewRowState.Added);
foreach (DataRow _ddr in addedRows)
{
_ddr.AcceptChanges();
}
I have a winforms application with two DataGridViews displaying a master-detail relationship from my Person and Address tables. Person table has a PersonID field that is auto-incrementing primary key. Address has a PersonID field that is the FK.
I fill my DataTables with DataAdapter and set Person.PersonID column's AutoIncrement=true and AutoIncrementStep=-1. I can insert records in the Person DataTable from the DataGridView. The PersonID column displays unique negative values for PersonID. I update the database by calling DataAdapter.Update(PersonTable) and the negative PersonIDs are converted to positive unique values automatically by SQL Server.
Here's the rub. The Address DataGridView show the address table which has a DataRelation to Person by PersonID. Inserted Person records have the temporary negative PersonID. I can now insert records into Address via DataGridView and Address.PersonID is set to the negative value from the DataRelation mapping. I call Adapter.Update(AddressTable) and the negative PersonIDs go into the Address table breaking the relationship.
How do you guys handle primary/foreign keys using DataTables and master-detail DataGridViews?
Thanks!
Steve
EDIT:
After more googling, I found that SqlDataAdapter.RowUpdated event gives me what I need. I create a new command to query the last id inserted by using ##IDENTITY. It works pretty well. The DataRelation updates the Address.PersonID field for me so it's required to Update the Person table first then update the Address table. All the new records insert properly with correct ids in place!
Adapter = new SqlDataAdapter(cmd);
Adapter.RowUpdated += (s, e) =>
{
if (e.StatementType != StatementType.Insert) return;
//set the id for the inserted record
SqlCommand c = e.Command.Connection.CreateCommand();
c.CommandText = "select ##IDENTITY id";
e.Row[0] = Convert.ToInt32( c.ExecuteScalar() );
};
Adapter.Fill(this);
SqlCommandBuilder sb = new SqlCommandBuilder(Adapter);
sb.GetDeleteCommand();
sb.GetUpdateCommand();
sb.GetInsertCommand();
this.Columns[0].AutoIncrement = true;
this.Columns[0].AutoIncrementSeed = -1;
this.Columns[0].AutoIncrementStep = -1;
You need to double click the relationship in the dataset designer, and select Cascade Updates. When your real SQL server generated PK values for your Person table are generated, it will automatically set the foreign key values in the address table as well.
You don't need to do any of that RowUpdated event stuff. Its built into the dataset functionality.
I had a similar problem, but my solution was a little different.
#Noel Kennedy: Your solution does not work with SQL Server 2005 CE, because it doesn't support multiple statements and the TableAdapter won't generate the refresh code needed to update the autoincrement columns in the parent table.
NOTE: You still need Cascade Updates in the relationship so the child tables get updated.
I also add a method in my TableAdapter, which is generic enough to just copy/paste in all your parent TableAdapters. The only thing that I change is the identity row type and index (if needed). I also add a query to the TableAdapter called GetIdentity(). You can add it to the TableAdapter in the dataset designer by adding a scalar query with sql="SELECT ##IDENTITY;"
Now the custom function is:
public int InsertAndRefresh(System.Data.DataTable dataTable)
{
int updated = 0;
System.Data.DataRow[] updatedRows = dataTable.Select("", "", System.Data.DataViewRowState.Added);
bool closed = (this.Connection.State == System.Data.ConnectionState.Closed);
if (closed)
this.Connection.Open();
foreach (System.Data.DataRow row in updatedRows)
{
updated+=this.Adapter.Update(new global::System.Data.DataRow[] { row });
decimal identity = (decimal)this.GetIdentity();
row[0] = System.Decimal.ToInt64(identity);
row.AcceptChanges();
}
if (closed)
this.Connection.Close();
return updated;
}
You want to call this on the parent first. Then do everything as usual (update parent and then children).
Cheers!