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
mysql> select bitmap_count(bitmap_and(to_bitmap(1), to_bitmap(2))) cnt;
+------+
| cnt |
+------+
| 0 |
+------+
mysql> select bitmap_to_string(bitmap_and(to_bitmap(1), to_bitmap(2)));
+----------------------------------------------------------+
| bitmap_to_string(bitmap_and(to_bitmap(1), to_bitmap(2))) |
+----------------------------------------------------------+
| |
+----------------------------------------------------------+
mysql> select bitmap_count(bitmap_and(to_bitmap(1), to_bitmap(1))) cnt;
+------+
| cnt |
+------+
| 1 |
+------+
MySQL> select bitmap_to_string(bitmap_and(to_bitmap(1), to_bitmap(1)));
+----------------------------------------------------------+
| bitmap_to_string(bitmap_and(to_bitmap(1), to_bitmap(1))) |
+----------------------------------------------------------+
| 1 |
+----------------------------------------------------------+
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_to_string(bitmap_and(bitmap_from_string('1,2,3'), bitmap_from_string('1,2'), bitmap_from_string('1,2,3,4,5'))) |
+-----------------------------------------------------------------------------------------------------------------------+
| 1,2 |
+-----------------------------------------------------------------------------------------------------------------------+
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()));
+---------------------------------------------------------------------------------------------------------------------------------------+
| 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())) |
+---------------------------------------------------------------------------------------------------------------------------------------+
| |
+---------------------------------------------------------------------------------------------------------------------------------------+
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));
+-----------------------------------------------------------------------------------------------------------------------------+
| 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)) |
+-----------------------------------------------------------------------------------------------------------------------------+
| NULL |
+-----------------------------------------------------------------------------------------------------------------------------+keywords
BITMAP_AND,BITMAP