BITMAP_AND_NOT,BITMAP_ANDNOT
描述
将两个 BITMAP 进行与非操作并返回计算结果,其中入参第一个叫 基准 BITMAP,第二个叫 排除 BITMAP。
别名
- BITMAP_ANDNOT
语法
BITMAP_AND_NOT(<bitmap1>, <bitmap2>)参数
| 参数 | 说明 |
|---|---|
<bitmap1> | 被求与非的基准 BITMAP |
<bitmap2> | 被求与非的排除 BITMAP |
返回值
返回一个 BITMAP。
- 当参数存在空值时,返回 NULL
举例
select bitmap_count(bitmap_and_not(bitmap_from_string('1,2,3'),bitmap_from_string('3,4,5'))) cnt;+------+
| cnt |
+------+
| 2 |
+------+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 |
+--------------------------------------------------------------------------------------------+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 |
+-------------------------------------------------------------------------------+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 |
+---------------------------------------------------------------------+