CODEWITHSUNDEEP
c#visual-studiodatagridviewdatatable
phv3773
phv3773

Reputation: 497

DataGridView: cannot add row or insert to table

I have a DataGridView. It uses a BindingSource, a DataTable in a DataSet, and a TableAdapter to add/change/delete data in a table. It worked OK, but stopped working when I added a field/column, and I can't figure out what I did or how fix it.

The user can add a new row at the bottom of the DataGridView, but when he goes to save, the row disappears and is not saved. In addition, if he tries to type a second new row, the first new row disappears.

Existing Rows can be changed and saved back to the database successfully.

I've been asked for code. OK, here is code. (I've eliminated some error checking done by scanning dtDep) The point that after the third line is executed, there are no rows in dtDep even though a new row had been entered into the DataGridView. If a row had been retrieved, it would be in dtDep and the database table updated by the last statement.

  this.Validate();
  bsBelkDep.EndEdit();
  DataTable dtDep = dsBelk.Tables["belk_elig_dep"];
  int n = belk_elig_depTableAdapter.Update(this.dsBelk.belk_elig_dep);

Upvotes: 0

Views: 565

Answers (2)

Richard Moss
Richard Moss

Reputation: 1620

This is a very old question and I have no way of knowing if it was the OP's original problem, but I had the exact same scenario and this is how I resolved it.

For background: I have a WinForms application built using datasets and an Access database. I migrated that to use Sqlite and anything but datasets. To avoid destroying the application completely, first I copied the strongly typed data tables out, tweaked them to account for changes in the schema and then used PetaPoco to perform the data operations. That worked fine for a single test conversion.

The trouble arose when I wanted to move on and convert all data tables - I wasn't happy manually writing the logic for converting to and from typed data rows and POCOs, so I fell back to writing old school T4 templates to generate typed DataTable, DataRow classes and the necessary remapping code.

Worked a treat - for editing or removing data. But new rows disappeared on "creation", the binding navigator count didn't increment, and of course, when saving, I didn't detect any rows with the RowState of DataRowState.Added. The grid at start up was subtly different - a blank value in all columns instead of a negative number in the ID column. In hindsight, that should have been a big clue.

On reverting the behaviour back to the manually extracted typed class the grid started working again so it was clearly an error in the new code.

End of background; tldr;

The cause of the issue, in my case, was that the my Id column didn't have the AutoIncrement property set. As soon as I configured that to be true (along with setting AutoIncrementSeed and AutoIncrementStep to -1, although neither are required) new rows started being correctly added to the table.

Upvotes: 0

phv3773
phv3773

Reputation: 497

It was a problem with the DataGridView, but I don't know what. I started deleting and re-creating the various object, and after the I recreated the DataGridView, it worked OK. Which was a pain because I have to do significant reformatting, but at least it works.

Upvotes: 0

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