MySQL如何查询最后一条记录

时间:2022-01-04 23:23:22

一、环境和数据准备

1.查看当前数据库中的表

mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| my_insert1 |
| my_insert2 |
+----------------+

2.查看my_insert1表结构

mysql> show create table my_insert1\G;
*************************** 1. row ***************************
Table: my_insert1
Create Table: CREATE TABLE `my_insert1` (
`name` varchar(10) CHARACTER SET latin1 DEFAULT NULL,
`password` varchar(32) CHARACTER SET latin1 DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)

3.查看my_insert2表结构  

mysql> show create table my_insert2\G;
*************************** 1. row ***************************
       Table: my_insert2
Create Table: CREATE TABLE `my_insert2` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(10) CHARACTER SET latin1 DEFAULT NULL,
  `password` varchar(32) CHARACTER SET latin1 DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)

4.向表my_insert1和my_insert2表中插入记录

mysql> insert into my_insert1(name,password) values ('黄飞鸿',password(123456)),('李小龙',password(123456));

mysql> insert into my_insert2(id,name,password) values (null,'黄飞鸿',password(123456)),(null,'李小龙',password(123456));

5.查看表的记录

mysql> select * from my_insert1;
+-----------+----------------------------------+
| name      | password                         |
+-----------+----------------------------------+
| 黄飞鸿    | *6BB4837EB74329105EE4568DDA7DC67 |
| 李小龙    | *6BB4837EB74329105EE4568DDA7DC67 |
+-----------+----------------------------------+

mysql> select * from my_insert2;
+----+-----------+----------------------------------+
| id | name      | password                         |
+----+-----------+----------------------------------+
|  1 | 黄飞鸿    | *6BB4837EB74329105EE4568DDA7DC67 |
|  2 | 李小龙    | *6BB4837EB74329105EE4568DDA7DC67 |
|  3 | 李连杰    | *6BB4837EB74329105EE4568DDA7DC67 |
+----+-----------+----------------------------------+

 

二、当表中没有ID自增长字段和有ID自增长查看最后一条记录的方式

1.由于my_insert1,没有ID自增长,查看当前表中有多少条记录

mysql> select count(*) from my_insert1;
+----------+
| count(*) |
+----------+
| 2 |
+----------+
1 row in set (0.00 sec)

2.查看当前表的第2行记录

mysql> select * from my_insert1 limit 1,1;
+-----------+----------------------------------+
| name | password |
+-----------+----------------------------------+
| 李小龙 | *6BB4837EB74329105EE4568DDA7DC67 |
+-----------+----------------------------------+
1 row in set (0.00 sec)

3.根据ID自增长,使用子查询查看表ID字段最大值

mysql> select *   from my_insert2 where id=(select max(id) from my_insert2);
+----+-----------+----------------------------------+
| id | name      | password                         |
+----+-----------+----------------------------------+
|  3 | 李连杰    | *6BB4837EB74329105EE4568DDA7DC67 |
+----+-----------+----------------------------------+

4.根据ID自增长,对ID字段进行倒序排序,并查看第一行

mysql> select * from my_insert2 order by id desc limit 1;
+----+-----------+----------------------------------+
| id | name      | password                         |
+----+-----------+----------------------------------+
|  3 | 李连杰    | *6BB4837EB74329105EE4568DDA7DC67 |
+----+-----------+----------------------------------+

5.可以根据当前insert语句使用函数last_insert_id(),查看最后一条记录

mysql> insert into my_insert2(id,name,password) values(null,'霍元甲',password('123456'));
Query OK, 1 row affected, 1 warning (0.00 sec)

mysql> select * from my_insert2 where id=(select last_insert_id());
+----+-----------+----------------------------------+
| id | name      | password                         |
+----+-----------+----------------------------------+
|  4 | 霍元甲    | *6BB4837EB74329105EE4568DDA7DC67 |
+----+-----------+----------------------------------+
1 row in set (0.00 sec)