ORA-01422: exact fetch returns more than requested number of rows

ORA-01422: exact fetch returns more than requested number of rows

Cause: The number specified in exact fetch is less than the rows returned.

Action: Rewrite the query or change number of rows requested

ORA-01422: "exact fetch returns more than requested number of rows":

This can be for one of the following three reasons:

1. There's a bug in the code and the developer did not realise that you could get more than one row returned;
2. The data has been hacked rather than using the API so that validation has been broken;
3. The software is OK, what the user did was OK, but two parallel updates occurred at the same time and neither could see the uncommitted change that the other did - hence not validated correctly.