Perform bitwise AND. This operator compares bits of two operands and returns 1 only if both corresponding bits are 1.
SELECT 2&1;
+-----+
| 2&1 |
+-----+
| 0 |
+-----+
SELECT 3&1;
+-----+
| 3&1 |
+-----+
| 1 |
+-----+
SELECT 29 & 15;
+---------+
| 29 & 15 |
+---------+
| 13 |
+---------+