mysql> create table sy(
-> num int);
query ok, 0 rows affected (0.03 sec)
mysql> alter table sy add column xiaoshu float;
query ok, 0 rows affected (0.04 sec)
records: 0 duplicates: 0 warnings: 0
mysql> insert sy (num,xiaoshu)values(1,2.0001);
query ok, 1 row affected (0.00 sec)
//ceil() 進一取整
mysql> select ceil(xiaoshu) from sy;
| ceil(xiaoshu) |
| 3 |
1 row in set (0.01 sec)
//div 整數除法
mysql> select xiaoshu div 2 from sy;
| xiaoshu div 2 |
| 1 |
//floor() 捨一取整
mysql> select floor(xiaoshu) from sy;
| floor(xiaoshu) |
| 2 |
1 row in set (0.01 sec)
//mod 取餘數或取模
mysql> select xiaoshu mod 2;
error 1054 (42s22): unknown column 'xiaoshu' in 'field list'
mysql> select xiaoshu mod 2 from sy;
| xiaoshu mod 2 |
| 0.00009989738464355469 |
1 row in set (0.00 sec)
mysql> select 10 mod 2;
| 10 mod 2 |
| 0 |
1 row in set (0.00 sec)
mysql> select mod(10,2);
| mod(10,2) |
| 0 |
1 row in set (0.00 sec)
//power() 冪運算
mysql> select power (num,3) from sy;
| power (num,3) |
| 1 |
1 row in set (0.01 sec)
mysql> select power (xiaoshu,3) from sy;
| power (xiaoshu,3) |
| 8.001198828493644 |
1 row in set (0.00 sec)
//round() 四捨五入
mysql> select round(xiaoshu) from sy;
| round(xiaoshu) |
| 2 |
1 row in set (0.00 sec)
mysql> insert sy(num,xiaoshu) values(2,2343.23425);
query ok, 1 row affected (0.01 sec)
mysql> delete from sy where num=1;
query ok, 1 row affected (0.00 sec)
//truncate 數字擷取
(123.34,-2)---10
mysql> select truncate(xiaoshu,-3) from sy;
| truncate(xiaoshu,-3) |
| 2000 |
1 row in set (0.00 sec)
//now() 當前日期和時間
mysql> select now();
| now() |
| 2017-05-10 20:40:25 |
1 row in set (0.00 sec)
//curdate() 當前日期
mysql> select curdate();
| curdate() |
| 2017-05-10 |
1 row in set (0.01 sec)
//curdate() 當前時間
mysql> select curtime();
| curtime() |
| 20:41:17 |
1 row in set (0.00 sec)
//加date
mysql> select date_add('2014-10-10', interval 100 day );
| date_add('2014-10-10', interval 100 day ) |
| 2015-01-18 |
1 row in set (0.01 sec)
//日期差
mysql> select datediff('2017-3-4','2015-4-3');
| datediff('2017-3-4','2015-4-3') |
| 701 |
1 row in set (0.01 sec)
//轉換格式
mysql> select date_format('2017-10-10','%m/%d/%y');
| date_format('2017-10-10','%m/%d/%y') |
| 10/10/17 |
1 row in set (0.00 sec)
mysql> select date_format('2017-10-10','%m/%d/%y');
| date_format('2017-10-10','%m/%d/%y') |
| 10/10/2017 |
1 row in set (0.00 sec)
//md5 轉換
mysql> select md5(xiaoshu) from sy;
| md5(xiaoshu) |
| e93b820d3439cdae3a9e977f42f63b48 |
1 row in set (0.01 sec)
//設定新密碼
mysql> set password = password('xinmima')
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