How many DB professionals have never had to deal with bitwise operations in SQL Server?  Who has never had a single value in the database represent more than one data value?  Have you ever had one of these fields serve as the(implicit or explicit) foreign key to a source table?

Sometimes it can seem a bit tricky dealing with such data – especially the last.  I’m not going to delve into the complexity of such scenarios.  I do want to present a basic intro however.

There are three basic operators for bitwise operations.  The operators are &, |, and ^.  These operators perform logical operations against integer type data.  Here is an example of what each would return when using the same values:

Code block

SELECT 175&75 AS BitAnd, 175|75 AS BitOr, 175^75 AS BitXOr

Code block

BitAndBitOrBitXOr
11239228

When performing a Bit & operation, the bits in the result are set to 1 if and only if both bits (for the current bit being resolved) in the input expressions have a value of 1.  Any other combination results in a 0.

When performing a Bit | operation, the bits in the result are set to 1 if either of the corresponding bits is a 1.  A 0 is returned when both values are 0 in the corresponding bit.

When performing a Bit ^ operation, the bits in the result are set to a value of 1 if 1 of the two bits (but not both) has a value of 1.  Any other combination (either all 0s or all 1s) will result in a value of 0.

As I work with this a bit, I will be sharing a particular scenario that has been quite interesting for me.