Database in trouble has a table with FLOAT column. It’s Front-End application verifies user’s input and inserts the data into that column using TRY_PARSE function.
The developer’s intention was that any “Not-a-Numeric” or “Out-of-Range” values will be automatically converted to NULL and it will be for user’s discretion to verify and fix these values.
However, one of the application users was very educated and instead of empty space, NULL or any other bad not numeric value the user supplied data with value of “NaN” for empty cells, which simply stands for “Not a Numeric”.
That action caused a database corruption!
Click through for a demo which you should not repeat on a work server.