What does the pipe operator do in SQL?

Question

I am redeveloping an application and have found this sql statement, what does the | character do in this part (au.ExNetBits | 8), I haven't seen before and can't find any answer online?

SELECT au.AccountID,au.ExNetBits FROM AccountUser au (NOLOCK)
WHERE au.CDAGUserId=102 and (au.ExNetBits | 8) = au.ExNetBits

Answer 1

from the MSDN documentation,

| (Bitwise OR) (Transact-SQL)

Performs a bitwise logical OR operation between two specified integer values as translated to binary expressions within Transact-SQL statements.

...

The bitwise | operator performs a bitwise logical OR between the two expressions, taking each corresponding bit for both expressions. The bits in the result are set to 1 if either or both bits (for the current bit being resolved) in the input expressions have a value of 1; if neither bit in the input expressions is 1, the bit in the result is set to 0.

If the left and right expressions have different integer data types (for example, the left expression is smallint and the right expression is int), the argument of the smaller data type is converted to the larger data type. In this example, the smallint expression is converted to an int.

for example, see this fiddle,

SELECT 1 | 1, 1 | 2, 2 | 4, 3 | 5;

outputs

1    3    6    7

to explain this behavior you must consider the bit patterns of the operands,

1 | 1

  00000001  = 1
| 00000001  = 1
_______________
  00000001  = 1

1 | 2

  00000001  = 1
| 00000010  = 2
_______________
  00000011  = 3

2 | 4

  00000010  = 2
| 00000100  = 4
_______________
  00000110  = 6

3 | 5

  00000011  = 3
| 00000101  = 5
_______________
  00000111  = 7