bitmap_and_not,bitmap_andnot

description

Syntax

BITMAP BITMAP_AND_NOT(BITMAP lhs, BITMAP rhs)

将两个bitmap进行与非操作并返回计算结果。

example

  1. mysql> select bitmap_count(bitmap_and_not(bitmap_from_string('1,2,3'),bitmap_from_string('3,4,5'))) cnt;
  2. +------+
  3. | cnt  |
  4. +------+
  5. |    2 |
  6. +------+
  8. mysql> select bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'),bitmap_from_string('3,4,5')));
  9. +--------------------------------------------------------------------------------------------+
  10. | bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'), bitmap_from_string('3,4,5'))) |
  11. +--------------------------------------------------------------------------------------------+
  12. | 1,2                                                                                        |
  13. +--------------------------------------------------------------------------------------------+
  14. 1 row in set (0.01 sec)
  16. mysql> select bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'),bitmap_empty())) ;
  17. +-------------------------------------------------------------------------------+
  18. | bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'), bitmap_empty())) |
  19. +-------------------------------------------------------------------------------+
  20. | 1,2,3                                                                         |
  21. +-------------------------------------------------------------------------------+
  23. mysql> select bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'),NULL));
  24. +---------------------------------------------------------------------+
  25. | bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'), NULL)) |
  26. +---------------------------------------------------------------------+
  27. | NULL                                                                |
  28. +---------------------------------------------------------------------+

keywords

  1. BITMAP_AND_NOT,BITMAP_ANDNOT,BITMAP