邏輯運(yùn)算符

邏輯運(yùn)算符用來(lái)判斷表達(dá)式的真假。如果表達(dá)式是真，結(jié)果返回 1。如果表達(dá)式是假，結(jié)果返回 0。

運(yùn)算符號(hào)	作用
NOT 或 !	邏輯非
AND	邏輯與
OR	邏輯或
XOR	邏輯異或

1、與

mysql> select 2 and 0;
+---------+
| 2 and 0 |
+---------+
|       0 |
+---------+mysql> select 2 and 1;   
+---------+     
| 2 and 1 |      
+---------+      
|       1 |      
+---------+

2、或

mysql> select 2 or 0;
+--------+
| 2 or 0 |
+--------+
|      1 |
+--------+mysql> select 2 or 1;
+--------+
| 2 or 1 |
+--------+
|      1 |
+--------+mysql> select 0 or 0;
+--------+
| 0 or 0 |
+--------+
|      0 |
+--------+mysql> select 1 || 0;
+--------+
| 1 || 0 |
+--------+
|      1 |
+--------+

3、非

mysql> select not 1;
+-------+
| not 1 |
+-------+
|     0 |
+-------+mysql> select !0;
+----+
| !0 |
+----+
|  1 |
+----+

4、異或

mysql> select 1 xor 1;
+---------+
| 1 xor 1 |
+---------+
|       0 |
+---------+mysql> select 0 xor 0;
+---------+
| 0 xor 0 |
+---------+
|       0 |
+---------+mysql> select 1 xor 0;
+---------+
| 1 xor 0 |
+---------+
|       1 |
+---------+mysql> select null or 1;
+-----------+
| null or 1 |
+-----------+
|         1 |
+-----------+mysql> select 1 ^ 0;
+-------+
| 1 ^ 0 |
+-------+
|     1 |
+-------+

位運(yùn)算符

位運(yùn)算符是在二進(jìn)制數(shù)上進(jìn)行計(jì)算的運(yùn)算符。位運(yùn)算會(huì)先將操作數(shù)變成二進(jìn)制數(shù)，進(jìn)行位運(yùn)算。然后再將計(jì)算結(jié)果從二進(jìn)制數(shù)變回十進(jìn)制數(shù)。

運(yùn)算符號(hào)	作用
&	按位與
丨	按位或
^	按位異或
!	取反
<<	左移
>>	右移

1、按位與

mysql> select 3&5;
+-----+
| 3&5 |
+-----+
|   1 |
+-----+

2、按位或

mysql> select 3|5;
+-----+
| 3|5 |
+-----+
|   7 |
+-----+

3、按位異或

mysql> select 3^5;
+-----+
| 3^5 |
+-----+
|   6 |
+-----+

4、按位取反

mysql> select ~18446744073709551612;
+-----------------------+
| ~18446744073709551612 |
+-----------------------+
|                     3 |
+-----------------------+

5、按位右移

mysql> select 3>>1;
+------+
| 3>>1 |
+------+
|    1 |
+------+

6、按位左移

mysql> select 3<<1;
+------+
| 3<<1 |
+------+
|    6 |
+------+

運(yùn)算符優(yōu)先級(jí)

最低優(yōu)先級(jí)為： :=。

最高優(yōu)先級(jí)為： !、BINARY、 COLLATE。