This is a follow up, puzzle of **SQL Puzzle – A Quick Fun with BitWise Operator**. Lots of people really like the earlier puzzle where I have used Bit Wise Operator AND and build a simple puzzle. Today we are going to use another bit wise operator – OR.

First execute following query:

SELECT 10 | 10

It will return us result as a 10.

Now execute following query:

SELECT 10 | 0

The above query will return us result as a 10 as well.

Now let us execute following query:

SELECT 1 | 100

It will return us result as a 101.

Here is the question back to you – **Why does the last query return us result as a 101 when we have used Bit Wise Operator OR?**

Reference: **Pinal Dave (http://blog.sqlauthority.com)**

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‘|’ does ORing on binary representation of a given no.

E.g. 1. 10|10

1010

| 1010 = 1010 which is 10

2. 10|0

1010

| 0000 = 1010 which is again 10

Similarly 1|100

0000001

| 1100100 = 1100101 which is 101

Hence the answer.

Or table

0 | 0 = 0

0 | 1 = 1

1 | 0 = 1

1 | 1 = 1

100

001

Result: 101

Just Like your yesterday’s puzzle.

This bitwise OR (|) operator also takes integer values as Parameters and convert them to Binary by self, and do bit by bit comparison.

like:

SELECT 1|100

will be translated as

select

0000001

1100100

and returns

1100101 (101 in decimal)

and this will be translated as integer before displaying

First of all, the result for last SELECT is wrong here, it is 101, not 10 as you show :)

Second, in the bitwise OR the rule is 1 | x = 1 for x either 0 or 1 and only 0 | 0 = 0.

100 has the last binary digit 0 (it divides by 2) and when we do 1 | 100 we get 101, because of the OR rule (1 | 0 = 1, 0 being the last binary digit of 100)

You can write this operation in binary mode:

1 | 1100100 = 1100101 = 101

Pinal, your “Results” image for “SELECT 1 | 100″ is incorrect — it should show a result of “101” rather than a result of “10”. The answer is 101 because the bitwise-OR returns a 1 for each bit that is one in either of the expressions — it should be obvious that 0 | 100 would result in 100, and the first expression, 1, adds a bit to the ones column, hence a result of 101.

Binary for 100 – 1100100

So 100 | 1 => 1100100 | 0000001 => 1100101 => 101

The logical OR operator is similar to AND as it works with two values. The difference is that where either of the bits at a specific location is set, the resultant bit will also be set. If both operands contain a zero at a position, the resultant bit will be clear. For example:

00000001 = 1

01100100 = 100

OR

01100101 = 101

So Select 1|100 would be 101.