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_count(bitmap_and(to_bitmap(1), to_bitmap(1))) cnt;
  9. +------+
  10. | cnt  |
  11. +------+
  12. |    1 |
  13. +------+
  15. MySQL> select bitmap_to_string(bitmap_and(to_bitmap(1), to_bitmap(1)));
  16. +----------------------------------------------------------+
  17. | bitmap_to_string(bitmap_and(to_bitmap(1), to_bitmap(1))) |
  18. +----------------------------------------------------------+
  19. | 1                                                        |
  20. +----------------------------------------------------------+
  22. 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')));
  23. +-----------------------------------------------------------------------------------------------------------------------+
  24. | bitmap_to_string(bitmap_and(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'))) |
  25. +-----------------------------------------------------------------------------------------------------------------------+
  26. | 1,2                                                                                                                   |
  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'),bitmap_empty()));
  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'), bitmap_empty())) |
  32. +---------------------------------------------------------------------------------------------------------------------------------------+
  33. |                                                                                                                                       |
  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'),NULL));
  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'), NULL)) |
  39. +-----------------------------------------------------------------------------------------------------------------------------+
  40. | NULL                                                                                                                        |
  41. +-----------------------------------------------------------------------------------------------------------------------------+

keyword

  1. BITMAP_AND,BITMAP