I have a simple problem with a not so simple solution… I am currently inserting some data into a database like this:
kompenzacijeDataSet.KompenzacijeRow kompenzacija = kompenzacijeDataSet.Kompenzacije.NewKompenzacijeRow(); kompenzacija.Datum = DateTime.Now; kompenzacija.PodjetjeID = stranka.id; kompenzacija.Znesek = Decimal.Parse(tbZnesek.Text); kompenzacijeDataSet.Kompenzacije.Rows.Add(kompenzacija); kompenzacijeDataSetTableAdapters.KompenzacijeTableAdapter kompTA = new kompenzacijeDataSetTableAdapters.KompenzacijeTableAdapter(); kompTA.Update(this.kompenzacijeDataSet.Kompenzacije); this.currentKompenzacijaID = LastInsertID(kompTA.Connection);
The last line is important. Why do I supply a connection? Well there is a SQLite function called last_insert_rowid() that you can call and get the last insert ID. Problem is it is bound to a connection and .NET seems to be reopening and closing connections for every dataset operation. I thought getting the connection from a table adapter would change things. But it doesn’t.
Would anyone know how to solve this? Maybe where to get a constant connection from? Or maybe something more elegant?
Thank you.
EDIT:
This is also a problem with transactions, I would need the same connection if I would want to use transactions, so that is also a problem…
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Answer
Using C# (.net 4.0) with SQLite, the SQLiteConnection class has a property LastInsertRowId
that equals the Primary Integer Key of the most recently inserted (or updated) element.
The rowID is returned if the table doesn’t have a primary integer key (in this case the rowID is column is automatically created).
See https://www.sqlite.org/c3ref/last_insert_rowid.html for more.
As for wrapping multiple commands in a single transaction, any commands entered after the transaction begins and before it is committed are part of one transaction.
long rowID; using (SQLiteConnection con = new SQLiteConnection([datasource]) { SQLiteTransaction transaction = null; transaction = con.BeginTransaction(); ... [execute insert statement] rowID = con.LastInsertRowId; transaction.Commit() }