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:
- There's a bug in the code and the developer did not realise that you could get more than one row returned;
- The data has been hacked rather than using the API so that validation has been broken;
- 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.