BITMAP_AND_COUNT

描述

计算两个及以上输入 BITMAP 的交集，返回交集的个数.

语法

BITMAP_AND_COUNT(<bitmap>, <bitmap>,[, <bitmap>...])

参数

参数	说明
<bitmap>	被求交集的原 BITMAP 之一

返回值

返回整数

• 当参数存在空值时，返回 NULL

举例

select bitmap_and_count(bitmap_from_string('1,2,3'),bitmap_from_string('3,4,5'));

+----------------------------------------------------------------------------+
| bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('3,4,5')) |
+----------------------------------------------------------------------------+
|                                                                          1 |
+----------------------------------------------------------------------------+

select bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'));

+-------------------------------------------------------------------------------------------------------------+
| (bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'))) |
+-------------------------------------------------------------------------------------------------------------+
|                                                                                                           2 |
+-------------------------------------------------------------------------------------------------------------+

select bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'),bitmap_empty());

+-----------------------------------------------------------------------------------------------------------------------------+
| (bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'), bitmap_empty())) |
+-----------------------------------------------------------------------------------------------------------------------------+
|                                                                                                                           0 |
+-----------------------------------------------------------------------------------------------------------------------------+

select bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'), NULL);

+-------------------------------------------------------------------------------------------------------------------+
| (bitmap_and_count(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'), NULL)) |
+-------------------------------------------------------------------------------------------------------------------+
|                                                                                                              NULL |
+-------------------------------------------------------------------------------------------------------------------+