BITMAP_AND_NOT,BITMAP_ANDNOT

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

mysql> select bitmap_count(bitmap_and_not(bitmap_from_string('1,2,3'),bitmap_from_string('3,4,5'))) cnt;
+------+
| cnt  |
+------+
|    2 |
+------+

mysql> select bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'),bitmap_from_string('3,4,5')));
+--------------------------------------------------------------------------------------------+
| bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'), bitmap_from_string('3,4,5'))) |
+--------------------------------------------------------------------------------------------+
| 1,2                                                                                        |
+--------------------------------------------------------------------------------------------+
1 row in set (0.01 sec)

mysql> select bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'),bitmap_empty())) ;
+-------------------------------------------------------------------------------+
| bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'), bitmap_empty())) |
+-------------------------------------------------------------------------------+
| 1,2,3                                                                         |
+-------------------------------------------------------------------------------+

mysql> select bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'),NULL));
+---------------------------------------------------------------------+
| bitmap_to_string(bitmap_and_not(bitmap_from_string('1,2,3'), NULL)) |
+---------------------------------------------------------------------+
| NULL                                                                |
+---------------------------------------------------------------------+

keywords

BITMAP_AND_NOT,BITMAP_ANDNOT,BITMAP