Returns the numeric representation of expr based on the fmt string or the default for expr's data type.
If expr is already a numeric, the value is not converted. If expr is a char value, fmt can be:
|Percent sign at right of number
|Dollar sign at left of number
|Display zero as blank
|Display leading zeros
|A digit position
|Delimiting character (not leading)
The default mask is as many nines (9s) as required for the number's precision and scale.
If expr is a date value, the returned numeric represents the number of days since year 0 and the portion of the last day.