MySQL 如何从表中获取新添加的记录

MySQL 如何从表中获取新添加的记录

为此,您可以使用带有LIMIT的ORDER BY。在这里,LIMIT用于设置要获取的记录的限制(计数)。让我们首先创建一个表−

mysql> create table DemoTable1486
   -> (
   -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   -> StudentName varchar(20)
   -> );
Query OK, 0 rows affected (0.66 sec)

使用插入命令在表中插入一些记录−

mysql> insert into DemoTable1486(StudentName) values('Chris Brown');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable1486(StudentName) values('David Miller');
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable1486(StudentName) values('John Doe');
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable1486(StudentName) values('John Smith');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable1486(StudentName) values('Adam Smith');
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable1486(StudentName) values('Carol Taylor');
Query OK, 1 row affected (0.16 sec)

使用select语句显示来自表的所有记录−

mysql> select * from DemoTable1486;

这将产生以下输出−

+-----------+--------------+
| StudentId | StudentName  |
+-----------+--------------+
|         1 | Chris Brown  |
|         2 | David Miller |
|         3 | John Doe     |
|         4 | John Smith   |
|         5 | Adam Smith   |
|         6 | Carol Taylor |
+-----------+--------------+
6 rows in set (0.00 sec)

以下是获取新添加的记录的查询−

mysql> select * from DemoTable1486
   -> order by StudentId desc
   -> limit 3;

这将产生以下输出−

+-----------+--------------+
| StudentId | StudentName  |
+-----------+--------------+
|         6 | Carol Taylor |
|         5 | Adam Smith   |
|         4 | John Smith   |
+-----------+--------------+
3 rows in set (0.00 sec)

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