MySQL 如何一次只获取N个行
要一次只获取N个行,您可以使用LIMIT运算符。以下是语法−
select * from yourTableName LIMIT 0,N;
让我们首先创建一个表−
mysql> create table DemoTable
(
Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
Name varchar(20)
);
Query OK, 0 rows affected (0.25 sec)
使用插入命令将一些记录插入表中−
mysql> insert into DemoTable(Name) values('John');
Query OK, 1 row affected (0.08 sec)
mysql> insert into DemoTable(Name) values('Larry');
Query OK, 1 row affected (0.07 sec)
mysql> insert into DemoTable(Name) values('Bob');
Query OK, 1 row affected (0.08 sec)
mysql> insert into DemoTable(Name) values('Sam');
Query OK, 1 row affected (0.07 sec)
mysql> insert into DemoTable(Name) values('Mike');
Query OK, 1 row affected (0.07 sec)
mysql> insert into DemoTable(Name) values('David');
Query OK, 1 row affected (0.06 sec)
mysql> insert into DemoTable(Name) values('Carol');
Query OK, 1 row affected (0.05 sec)
mysql> insert into DemoTable(Name) values('Ramit');
Query OK, 1 row affected (0.06 sec)
mysql> insert into DemoTable(Name) values('Adam');
Query OK, 1 row affected (0.03 sec)
mysql> insert into DemoTable(Name) values('Chris');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable(Name) values('Robert');
Query OK, 1 row affected (0.06 sec)
mysql> insert into DemoTable(Name) values('James');
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable(Name) values('Jace');
Query OK, 1 row affected (0.05 sec)
使用select语句显示表中的所有记录−
mysql> select *from DemoTable;
这将产生以下输出−
+----+--------+
| Id | Name |
+----+--------+
| 1 | John |
| 2 | Larry |
| 3 | Bob |
| 4 | Sam |
| 5 | Mike |
| 6 | David |
| 7 | Carol |
| 8 | Ramit |
| 9 | Adam |
| 10 | Chris |
| 11 | Robert |
| 12 | James |
| 13 | Jace |
+----+--------+
13 rows in set (0.00 sec)
以下是一次仅获取N个行的查询。这里,我们只获取10行−
mysql> select *from DemoTable LIMIT 0,10;
这将产生以下输出−
+----+-------+
| Id | Name |
+----+-------+
| 1 | John |
| 2 | Larry |
| 3 | Bob |
| 4 | Sam |
| 5 | Mike |
| 6 | David |
| 7 | Carol |
| 8 | Ramit |
| 9 | Adam |
| 10 | Chris |
+----+-------+
10 rows in set (0.00 sec)
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