MySql Insert signal if where clause fails As part of a chained sequence of transactional queries, I'm inserting values that exist in a temporary table into a new table.

Every query is validated for errors in PHP using:

if (!mysqli_query($dbc, ....) {$errors[] = mysqli_error($dbc);}


If an error occurs it gets pushed into the errors array and the entire sequence is not commited.

With this approach I'm having trouble validatiesg queries that DO NOT CAUSE AN ERROR but DO NOT MEET WHERE CLAUSE CONDITIONS

Is there a way to get MySQL to throw an error signal when the WHERE CLAUSE conditions are not met?
You can try using mysqli_affected_rows to find how many rows are inserted from the last query and generate your own error in case no rows are inserted.