@Mohamed_Gaber Hi Mohamed, when you edit a row in your app, AppSheet will construct and execute a SQL query to make the corresponding change to the row in your database. The constructed query will have a WHERE clause for identifying the row to edit. This WHERE clause relies on the key column of the table to find the row. However, the current key column of your table is the _RowNumber column, which does not exist in your database. As a result, the query will fail.
As a rule of thumb, you should never use the _RowNumber column as the key column if your table comes from a SQL database. To fix this problem, you must choose a different column that exists in the database as the key column. Ideally, this column should also be the primary key column of your SQL table, although any column that has unique values for each row will also work.