在mysql中如何取数据库中的某几行数据

mysql中limit用法

使用查询语句的时候，经常要返回前几条或者中间某几行数据，这个时候怎么办呢？不用担心，mysql已经为我们提供了这样一个功能。

SELECT * FROM table LIMIT [offset,] rows | rows OFFSET offset

LIMIT 子句可以被用于强制 SELECT 语句返回指定的记录数。LIMIT 接受一个或两个数字参数。参数必须是一个整数常量。如果给定两个参数，第一个参数指定第一个返回记录行的偏移量，第二个参数指定返回记录行的最大数目。初始记录行的偏移量是 0(而不是 1)：为了与 PostgreSQL 兼容，MySQL 也支持句法： LIMIT # OFFSET #。

mysql> SELECT * FROM table LIMIT 5,10; // 检索记录行 6-15

//为了检索从某一个偏移量到记录集的结束所有的记录行，可以指定第二个参数为 -1：
mysql> SELECT * FROM table LIMIT 95,-1; // 检索记录行 96-last.

//如果只给定一个参数，它表示返回最大的记录行数目：
mysql> SELECT * FROM table LIMIT 5; //检索前 5 个记录行

//换句话说，LIMIT n 等价于 LIMIT 0,n。

实例：

mysql> use sppeivan;
Database changed
mysql> select * from employee; // 返回所有结果
+------------+------------+--------+-------------+
| username | password | gender | cellphone |
+------------+------------+--------+-------------+
| ewrew | erewr | MAN | 13618889076 |
| ewrwerw32r | 324324 | MAN | 13618889076 |
| grrrrr | r44343 | WOMAN | 13618889076 |
| pansong | erewrwe | MAN | 13618889076 |
| ret43t43t | 43t43 | MAN | 13618889076 |
| ret44t4 | r4tgr | WOMAN | 13618889076 |
| tttt | 4et | WOMAN | 13618889076 |
| wr34r | retre | MAN | 13618889076 |
| xxx | safe | MAN | 13618889076 |
| hhh | ewrwer | MAN | 13618889076 |
| hg | 6574326543 | MAN | 13618889076 |
| ps | ewrwe | MAN | 13618889076 |
| zhu | werew | MAN | 13618889076 |
+------------+------------+--------+-------------+
13 rows in set (0.01 sec)

mysql> select * from employee limit 3 7;
ERROR 1064 (42000): You have an error in your SQL syntax
corresponds to your MySQL server version for the right s
line 1
mysql> select * from employee limit 3, 7; // 返回4-11行
+-----------+----------+--------+-------------+
| username | password | gender | cellphone |
+-----------+----------+--------+-------------+
| pansong | erewrwe | MAN | 13618889076 |
| ret43t43t | 43t43 | MAN | 13618889076 |
| ret44t4 | r4tgr | WOMAN | 13618889076 |
| tttt | 4et | WOMAN | 13618889076 |
| wr34r | retre | MAN | 13618889076 |
| xxx | safe | MAN | 13618889076 |
| hhh | ewrwer | MAN | 13618889076 |
+-----------+----------+--------+-------------+
7 rows in set (0.00 sec)

mysql> select * from employee limit 3,-1; // 错误语法
ERROR 1064 (42000): You have an error in your SQL syntax
corresponds to your MySQL server version for the right s
t line 1

mysql> select * from employee limit 3; // 返回前3行

+------------+----------+--------+-------------+
| username | password | gender | cellphone |
+------------+----------+--------+-------------+
| ewrew | erewr | MAN | 13618889076 |
| ewrwerw32r | 324324 | MAN | 13618889076 |
| grrrrr | r44343 | WOMAN | 13618889076 |
+------------+----------+--------+-------------+
3 rows in set (0.00 sec)

mysql> select * from employee limit 10; // 返回前10行

+------------+----------+--------+-------------+
| username | password | gender | cellphone |
+------------+----------+--------+-------------+
| ewrew | erewr | MAN | 13618889076 |
| ewrwerw32r | 324324 | MAN | 13618889076 |
| grrrrr | r44343 | WOMAN | 13618889076 |
| pansong | erewrwe | MAN | 13618889076 |
| ret43t43t | 43t43 | MAN | 13618889076 |
| ret44t4 | r4tgr | WOMAN | 13618889076 |
| tttt | 4et | WOMAN | 13618889076 |
| wr34r | retre | MAN | 13618889076 |
| xxx | safe | MAN | 13811588469 |
| hhh | ewrwer | MAN | 13618889076 |
+------------+----------+--------+-------------+
10 rows in set (0.00 sec)

在mysql中如何取数据库中的某几行数据

猜你喜欢