The rules that are applicable for the bulk-copy transfer values.
NULL values:
If a source column contains NULL values but the destination does not allow them, the row is rejected.
All numeric conversions use rounding.
Any loss of digits to the left of the decimal results in an error. For example, an integer of value 123 could not be converted to a decimal(4,2) value without losing a digit to the left of the decimal point.
Any loss of digits to the right of the decimal point is not considered an error. For example, a float of value 123.456 would be converted to an integer value of 123 without error.
Binary data:
Binary data is transferred to a binary column without byte translation. A byte value in the source will have the same value in the destination.