開發指南—函數—位函數

PolarDB-X支援的标量位函數

函數名	描述
｜	按位或
^	按位異或
&	按位與
BIT_COUNT()	統計二進制數中1的個數

PolarDB-X支援的聚合位函數

BIT_OR()
BIT_XOR()
BIT_AND()

示例

BIT_COUNT()傳回參數對應的二進制數中1的個數；若參數為NULL，則傳回NULL。

mysql> SELECT BIT_COUNT(29), BIT_COUNT(b'101010');
+--------------+----------------------+
| BIT_COUNT(29) | BIT_COUNT(b'101010') |
+--------------+----------------------+
|            4 |                    3 |
+--------------+----------------------+
1 row in set (0.00 sec)
mysql> SELECT BIT_COUNT(NULL);
+-----------------+
| BIT_COUNT(NULL) |
+-----------------+
|            NULL |
+-----------------+
1 row in set (0.00 sec)
mysql> SELECT 3 & 2;
+-------+
| 3 & 2 |
+-------+
|     2 |
+-------+
1 row in set (0.01 sec)