Why does ExecuteNonQuery return 1 even if nothing was updated?

Question

I have a query like: ``` UPDATE messages SET Unread = 'N' WHERE id= '6' ``` To read affected rows, I use the value of `ExecuteNonQuery()`, but it always returns 1 even if nothing is changed. Saw the same problem here. Is this a bug or is this behavior normal?

Accepted Answer

For `ExecuteNonQuery` to return `1` there must be a record `WHERE id = '6'`. Now, if you only want to update the row if the value is different then change the query:

```
UPDATE messages SET Unread = 'N' WHERE id = '6' AND Unread <> 'N'
```

If you were to run that query and the value of `Unread` was already `'N'` then it would return `0` rows.

Why does ExecuteNonQuery return 1 even if nothing was updated?

Solution

Problem