一、算術運算符
1、加 ?www.2cto.com ?
mysql> select 1+2;
+-----+
| 1+2 |
+-----+
| ? 3 |
+-----+
2、減
mysql> select 1-2;
+-----+
| 1-2 |
+-----+
| ?-1 |
+-----+
3、乘
mysql> select 2*3;
+-----+
| 2*3 |
+-----+
| ? 6 |
+-----+
4、除
mysql> select 2/3;
+--------+
| 2/3 ? ?|
+--------+
| 0.6667 |
+--------+
5、商 ?www.2cto.com ?
mysql> select 10 DIV 4;
+----------+
| 10 DIV 4 |
+----------+
| ? ? ? ?2 |
+----------+
6、取余
mysql> select 10 MOD 4;
+----------+
| 10 MOD 4 |
+----------+
| ? ? ? ?2 |
+----------+
二、比較運算符
1、等于
mysql> select 2=3;
+-----+
| 2=3 |
+-----+
| ? 0 |
+-----+
mysql> select NULL = NULL;
+-------------+
| NULL = NULL |
+-------------+
| ? ? ? ?NULL |
+-------------+
2、不等于
mysql> select 2<>3;
+------+
| 2<>3 |
+------+
| ? ?1 |
+------+
3、安全等于
與“=”的區別在于當兩個操作碼均為NULL時，其所得值為1而不為NULL，而當一個操作碼為NULL時，其所得值為0而不為NULL。
mysql> select 2<=>3;
+-------+
| 2<=>3 |
+-------+
| ? ? 0 |
+-------+
mysql> select null=null;
+-----------+
| null=null |
+-----------+
| ? ? ?NULL |
+-----------+
mysql> select null<=>null;
+-------------+
| null<=>null |
+-------------+
| ? ? ? ? ? 1 |
+-------------+
4、小于
mysql> select 2<3;
+-----+
| 2<3 |
+-----+
| ? 1 |
+-----+
5、小于等于
mysql> select 2<=3;
+------+
| 2<=3 |
+------+
| ? ?1 |
+------+
6、大于
mysql> select 2>3;
+-----+
| 2>3 |
+-----+
| ? 0 |
+-----+
7、大于等于
mysql> select 2>=3;
+------+
| 2>=3 |
+------+
| ? ?0 |
+------+
8、BETWEEN
mysql> select 5 between 1 and 10;
+--------------------+
| 5 between 1 and 10 |
+--------------------+
| ? ? ? ? ? ? ? ? ?1 |
+--------------------+
9、IN
mysql> select 5 in (1,2,3,4,5);
+------------------+
| 5 in (1,2,3,4,5) |
+------------------+
| ? ? ? ? ? ? ? ?1 |
+------------------+
10、NOT IN
mysql> select 5 not in (1,2,3,4,5);
+----------------------+
| 5 not in (1,2,3,4,5) |
+----------------------+
| ? ? ? ? ? ? ? ? ? ?0 |
+----------------------+
11、IS NULL
mysql> select null is NULL;
+--------------+
| null is NULL |
+--------------+
| ? ? ? ? ? ?1 |
+--------------+
mysql> select 'a' is NULL;
+-------------+
| 'a' is NULL |
+-------------+
| ? ? ? ? ? 0 |
+-------------+
12、IS NOT NULL
mysql> select null IS NOT NULL;
+------------------+
| null IS NOT NULL |
+------------------+
| ? ? ? ? ? ? ? ?0 |
+------------------+
mysql> select 'a' IS NOT NULL;
+-----------------+
| 'a' IS NOT NULL |
+-----------------+
| ? ? ? ? ? ? ? 1 |
+-----------------+
13、LIKE
mysql> select '12345' like '12%';
+--------------------+
| '12345' like '12%' |
+--------------------+
| ? ? ? ? ? ? ? ? ?1 |
+--------------------+
mysql> select '12345' like '12_';
+--------------------+
| '12345' like '12_' |
+--------------------+
| ? ? ? ? ? ? ? ? ?0 |
+--------------------+
14、REGEXP
mysql> select 'beijing' REGEXP 'jing';
+-------------------------+
| 'beijing' REGEXP 'jing' |
+-------------------------+
| ? ? ? ? ? ? ? ? ? ? ? 1 |
+-------------------------+
mysql> select 'beijing' REGEXP 'xi';
+-----------------------+
| 'beijing' REGEXP 'xi' |
+-----------------------+
| ? ? ? ? ? ? ? ? ? ? 0 |
+-----------------------+
三、邏輯運算符 ?www.2cto.com ?
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 ?www.2cto.com ?
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 |
+-------+
四、位運算符
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
+----------------------+
| ~3 ? ? ? ? ? ? ? ? ? |
+----------------------+
| 18446744073709551612 |
+----------------------+
mysql> select ~18446744073709551612;
+-----------------------+
| ~18446744073709551612 |
+-----------------------+
| ? ? ? ? ? ? ? ? ? ? 3 |
+-----------------------+
5、按位右移 ?www.2cto.com ?
mysql> select 3>>1;
+------+
| 3>>1 |
+------+
| ? ?1 |
+------+
6、按位左移
mysql> select 3<<1;
+------+
| 3<<1 |
+------+
| ? ?6 |
+------+
五、運算符優先級順序
最高優先級 :=
1 ||, OR, XOR
2 &&, AND
3 BETWEEN, CASE, WHEN, THEN, ELSE
4 =, <=>, >=, >, <=, <, <>, !=, IS, LIKE, REGEXP, IN
5 |
6 &
7 <<, >>
8 -, +
9 *, /, DIV, %, MOD
10 ^
11 - (unary minus), ~ (unary bit inversion)
12 !, NOT
最低優先級 BINARY, COLLATE
