Deprecated. Don't use for new development and try to migrate existing uses.
This function can be used to validate if a conversion to the bigint datatype is possible for a given string.
The special case of a null-string will give a return value of 0.
Use the built-in SQL server function
SELECT TRY_CONVERT(bigint, x);
Be careful with differences in behavior for '' and trailing/leading whitespace characters, space, tab new line etc.
Returns 1 if conversion is possible and 0 otherwise.