bitmap_and

description

Syntax

BITMAP BITMAP_AND(BITMAP lhs, BITMAP rhs)

计算两个及以上输入bitmap的交集，返回新的bitmap.

example

1. mysql> select bitmap_count(bitmap_and(to_bitmap(1), to_bitmap(2))) cnt;
2. +------+
3. | cnt  |
4. +------+
5. |    0 |
6. +------+

8. mysql> select bitmap_to_string(bitmap_and(to_bitmap(1), to_bitmap(2)));
9. +----------------------------------------------------------+
10. | bitmap_to_string(bitmap_and(to_bitmap(1), to_bitmap(2))) |
11. +----------------------------------------------------------+
12. |                                                          |
13. +----------------------------------------------------------+

15. mysql> select bitmap_count(bitmap_and(to_bitmap(1), to_bitmap(1))) cnt;
16. +------+
17. | cnt  |
18. +------+
19. |    1 |
20. +------+

22. MySQL> select bitmap_to_string(bitmap_and(to_bitmap(1), to_bitmap(1)));
23. +----------------------------------------------------------+
24. | bitmap_to_string(bitmap_and(to_bitmap(1), to_bitmap(1))) |
25. +----------------------------------------------------------+
26. | 1                                                        |
27. +----------------------------------------------------------+

29. MySQL> select bitmap_to_string(bitmap_and(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5')));
30. +-----------------------------------------------------------------------------------------------------------------------+
31. | bitmap_to_string(bitmap_and(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'))) |
32. +-----------------------------------------------------------------------------------------------------------------------+
33. | 1,2                                                                                                                   |
34. +-----------------------------------------------------------------------------------------------------------------------+

36. MySQL> select bitmap_to_string(bitmap_and(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'),bitmap_empty()));
37. +---------------------------------------------------------------------------------------------------------------------------------------+
38. | bitmap_to_string(bitmap_and(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'), bitmap_empty())) |
39. +---------------------------------------------------------------------------------------------------------------------------------------+
40. |                                                                                                                                       |
41. +---------------------------------------------------------------------------------------------------------------------------------------+

43. MySQL> select bitmap_to_string(bitmap_and(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'),NULL));
44. +-----------------------------------------------------------------------------------------------------------------------------+
45. | bitmap_to_string(bitmap_and(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'), NULL)) |
46. +-----------------------------------------------------------------------------------------------------------------------------+
47. | NULL                                                                                                                        |
48. +-----------------------------------------------------------------------------------------------------------------------------+

keywords

1. BITMAP_AND,BITMAP