Mysql DBA 高级运维学习笔记-DML语句之insert知识讲解

Posted 2020-10-22

9.9.7.8 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test1

Create Table: CREATE TABLE `test1` (
  `id` int(4) NOT NULL AUTO_INCREMENT,
  `name` char(20) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1

（3）往表中插入数据的不同的例子

a.按规矩指定所有列名，并且每列都插入值

Insert into test(id,name) values(1,’zbf’);
[email protected] 12:0600-> insert into test(id,name) values(1,‘zbf‘);
Query OK, 1 row affected (0.00 sec)

[email protected] 12:1313->select * from test;
+----+------+
| id | name |
+----+------+
|  1 | zbf  |
+----+------+
1 row in set (0.00 sec)

b.由于id列为自增的,所以只在name列插入值

[email protected] 12:1329-> insert into test(name) values(‘wwnwan‘);
Query OK, 1 row affected (0.00 sec)

[email protected] 12:1738->select * from test;
+----+--------+
| id | name   |
+----+--------+
|  1 | zbf|
|  2 | wwnwan |
+----+--------+
2 rows in set (0.00 sec)

c.如果不指定列，就要按规矩为每列都插入适当的值

[email protected] 12:1742->insert into test values(3,‘lisi‘);
Query OK, 1 row affected (0.00 sec)
[email protected] 12:2349->select * from test;
+----+--------+
| id | name   |
+----+--------+
|  1 | zbf|
|  2 | wwnwan |
|  3 | lisi   |
+----+--------+

d.批量插入数据方法提升效率。

[email protected] 12:2630->insert into test values(4,‘woshishei‘),(5,‘nimei‘);
Query OK, 2 rows affected (0.00 sec)
Records: 2  Duplicates: 0  Warnings: 0

[email protected] 12:2708->select * from test;
+----+-----------+
| id | name  |
+----+-----------+
|  1 | zbf   |
|  2 | wwnwan|
|  3 | lisi  |
|  4 | woshishei |
|  5 | nimei |
+----+-----------+

e.删除数据（慎用）

[email protected] 12:2723->delete from test;
Query OK, 5 rows affected (0.00 sec)

[email protected] 12:4005->select * from test;
Empty set (0.00 sec)

f.批量插入演示

[email protected] 12:4502->select * from test;
+----+-----------+
| id | name  |
+----+-----------+
|  1 | wwnwan|
|  2 | zbf   |
|  3 | lisi  |
|  4 | woshishei |
|  5 | nimei |

g.测试完毕，退出数据库，然后备份上述数据，留着备用。备份后检查备份的sql数据内容；过滤无用信息。

[[email protected] ~]# mysqldump -usystem -pzbf666 -B wwn >/opt/zbf_bak.sql
[[email protected] ~]# grep -E -v "#|\/|^$|--" /opt/zbf_bak.sql

h.一个错误的备份案列，如果不检查备份数据可能导致数据不是想要的

[[email protected] ~]# mysqldump -usystem -pzbf666 -A -B wwn >/opt/zbf_bak1.sql
[[email protected] ~]# grep -E -v "#|\/|^$|--" /opt/zbf_bak1.sql 
Usage: mysqldump [OPTIONS] database [tables]

提示：

1. -A备份所有的库，-B备份指定的库
2. 5.1.68版本[[email protected] ~]# mysqldump -usystem -pzbf666 –A -B --events >/opt/zbf_bak.sql

补充强调：我们平时登录网站发帖子，发博文，实质上就是调用网站的程序连接mysql数据库，通过上述insert语句把帖子博文数据存入数据库的。