Safe functions for casting numbers and timestamp in Oracle SQL
In the process of importing data which can be irregular from a flat file it is convenient to import all values as character strings, in this case Oracle’s varchar2, and then cast them into the proper format using the built-in datatype converters as e.g. to_number. The problem occurs when some value which is not convertible is stored in the column. This could be either because table column-overflow in the import process or because the value is optional and may be…