MySQL数据库应用(8)DML语句之insert知识

一、往表中插入数据

    1、命令语法:

    insert into <表名> [(<字段名1>[,..<字段名n>])] values (值1)[,(值n)]

    2、新建一个简单的测试表test

create table `test`(
`id` int(4) not null auto_increment,
`name` char(20) not null,
primary key (`id`)
);

    3、往表中插入数据的不同的语法例子:

        1)按规矩指定所有列名,并且每列都插入值

mysql> insert into test(id,name) values(1,'oldboy');
Query OK, 1 row affected (0.00 sec)

mysql> select * from test;
+----+--------+
| id | name   |
+----+--------+
|  1 | oldboy |
+----+--------+
1 row in set (0.00 sec)

        2)由于id列为自增的,所有,可以只在name列插入值

mysql> insert into test(name) values('oldgirl');
Query OK, 1 row affected (0.11 sec)

mysql> select * from test;
+----+---------+
| id | name    |
+----+---------+
|  1 | oldboy  |
|  2 | oldgirl |
+----+---------+
2 rows in set (0.00 sec)

        3)如果不知道列,就要按规矩为每列都插入恰当的值

mysql> insert into test values(3,'inca');
Query OK, 1 row affected (0.36 sec)

mysql> select * from test;
+----+---------+
| id | name    |
+----+---------+
|  1 | oldboy  |
|  2 | oldgirl |
|  3 | inca    |
+----+---------+
3 rows in set (0.00 sec)

        4)批量插入数据方法,提升效率

mysql> insert into test values(4,'zuma'),(5,'kaka');      #批量插入2条记录,提升效率
Query OK, 2 rows affected (0.35 sec)
Records: 2  Duplicates: 0  Warnings: 0

mysql> select * from test;
+----+---------+
| id | name    |
+----+---------+
|  1 | oldboy  |
|  2 | oldgirl |
|  3 | inca    |
|  4 | zuma    |
|  5 | kaka    |
+----+---------+
5 rows in set (0.00 sec)

insert into `test` values (1,'oldboy'),(2,'oldgirl'),(3,'inca'),(4,'zuma'),(5,'kaka');

    4、插入数据实践演示:

mysql> delete from test;
Query OK, 5 rows affected (0.36 sec)

mysql> select * from test;
Empty set (0.00 sec)

mysql> insert into `test` values (1,'oldboy'),(2,'oldgirl'),(3,'inca'),(4,'zuma'),(5,'kaka');
Query OK, 5 rows affected (0.10 sec)
Records: 5  Duplicates: 0  Warnings: 0

mysql> select * from test;
+----+---------+
| id | name    |
+----+---------+
|  1 | oldboy  |
|  2 | oldgirl |
|  3 | inca    |
|  4 | zuma    |
|  5 | kaka    |
+----+---------+
5 rows in set (0.00 sec)

     5、测试完毕,退出数据库,然后备份上述数据,留着备用:

[root@localhost ~]# mysqldump -uroot -pdubin -B oldboy >/opt/oldboy_bak.sql
[root@localhost ~]# ls -l /opt/oldboy_bak.sql 
-rw-r--r--. 1 root root 2826 9月  20 08:42 /opt/oldboy_bak.sql
[root@localhost ~]# 

    6、备份后检查备份的sql数据内容:过滤无用信息

[root@localhost ~]# grep -E -v "#|\/|^$|--" /opt/oldboy_bak.sql 
USE `oldboy`;
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student` (
  `id` int(4) NOT NULL AUTO_INCREMENT,
  `name` char(20) NOT NULL,
  `age` tinyint(2) NOT NULL DEFAULT '0',
  `dept` varchar(16) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uni_inde_name` (`name`),
  KEY `index_dept` (`dept`(8)),
  KEY `ind_name_dept` (`name`(8),`dept`(10))
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
LOCK TABLES `student` WRITE;
UNLOCK TABLES;
DROP TABLE IF EXISTS `test`;
CREATE TABLE `test` (
  `id` int(4) NOT NULL AUTO_INCREMENT,
  `name` char(20) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=latin1;
LOCK TABLES `test` WRITE;
INSERT INTO `test` VALUES (1,'oldboy'),(2,'oldgirl'),(3,'inca'),(4,'zuma'),(5,'kaka');
UNLOCK TABLES;

    7、一个备份错误案例:如果不检查备份数据可能导致数据不是想要的。

[root@localhost ~]# mysqldump -uroot -pdubin -A -B oldboy >/opt/oldboy_bak1.sql
[root@localhost ~]# grep -E -v "#|\/|^$|--" /opt/oldboy_bak1.sql 
Usage: mysqldump [OPTIONS] database [tables]
[root@localhost ~]# cat /opt/oldboy_bak1.sql 
Usage: mysqldump [OPTIONS] database [tables]
OR     mysqldump [OPTIONS] --databases [OPTIONS] DB1 [DB2 DB3...]
OR     mysqldump [OPTIONS] --all-databases [OPTIONS]
For more options, use mysqldump --help

提示:
1、错误的点事 -A 表示所有库,后面不能指定oldboy库了
2、5.1.68版本:
[root@localhost ~]# mysqldump -uroot -pdubin -A -B --event >/tmp/oldboy_bak.sql

     8、补存强调:我们平时登录网站发帖子,发博文,实质上都是调用web网站的程序连接MySQL数据库,通过上述的insert语句把帖子博文数据存入数据库的。

转载于:https://www.cnblogs.com/cnxy168/p/11594362.html

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