bitmap_and

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_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