1. Introduction to IDE tools
The production environment is still recommended to use the mysql command line, but in order to facilitate our testing, you can use the IDE tool download link: https://pan.baidu.com/s/1bpo5mqj
master:
1. Test + link database
2. Create a new library
3. Create a new table, add fields + types + constraints
4. Design Tables: Foreign Keys
5. New query
6. Backup library/table
Notice:
Add comments in batches: ctrl+? key
To comment in batches: ctrl+shift+? key
Two MySQL data backup
1. Explanation of terms
Physical Backup: Directly copy database files, suitable for large database environments. But it cannot be restored to heterogeneous systems such as Windows.
Logical backup: The backup is the SQL statement executed by the operations such as table creation, database creation, and insertion. It is suitable for small and medium-sized databases, and the efficiency is relatively low.
Export Table: Import the table into a text file.
2. Use mysqldump to implement logical backup
Syntax: mysqldump -h server -u username -p password database name > backup file.sql
Example:
Single database backup
mysqldump -uroot -p123 db1 > db1.sql
mysqldump -uroot -p123 db1 table1 table2 > db1-table1-table2.sql
Multi-database backup
mysqldump -uroot -p123 --databases db1 db2 mysql db3 > db1_db2_mysql_db3.sql
Backup all libraries
mysqldump -uroot -p123 --all-databases > all.sql
3. Restore logical backup
Method 1: mysql -uroot -p123 < /backup/all.sql
Method Two:
mysql> use db1;
mysql> SET SQL_LOG_BIN=0;
mysql> source /root/db1.sql
Note: If you back up/restore a single library, you can modify the sql file
DROP database if exists school;
create database school;
use school;
4. Backup/Restore Case
Experiment 1: Database corruption
Backup:
#mysqldump -uroot -p123 --all-databases > /backup/`date +%F`_all.sql
#mysql -uroot -p123 -e 'flush logs' //truncate and generate new binlog
insert data //simulate the server is up and running
mysql> set sql_log_bin=0; //Simulate server damage
mysql> drop database db;
recover:
#mysqlbinlog last binlog > /backup/last_bin.log
mysql> set sql_log_bin=0;
mysql> source /backup/2014-02-13_all.sql //Restore the last full backup
mysql> source /backup/last_bin.log //Restore the last binlog file
Experiment 2: If you delete it by mistake
Backup:
mysqldump -uroot -p123 --all-databases > /backup/`date +%F`_all.sql
mysql -uroot -p123 -e 'flush logs' // truncate and generate new binlog
insert data //simulate the server is up and running
drop table db1.t1 //Simulate accidental deletion
insert data //simulate the server is up and running
recover:
#mysqlbinlog last binlog --stop-position=260 > /tmp/1.sql
#mysqlbinlog last binlog --start-position=900 > /tmp/2.sql
mysql> set sql_log_bin=0;
mysql> source /backup/2014-02-13_all.sql //Restore the last full backup
mysql> source /tmp/1.log //Restore the last binlog file
mysql> source /tmp/2.log //Restore the last binlog file
Precautions:
1. Fully restore to a clean environment (eg new database or delete old database)
2. All SQL statements should not be logged to binlog during recovery
5. Realize automatic backup
Backup plan:
1) What time is 2:00
2) Which databases are backed up
3) The location of the backup file
Backup script:
vim /mysql_back.sql
#!/bin/bash
back_dir=/backup
back_file=`date +%F`_all.sql
user=root
pass=123
if [ ! -d /backup ];then
mkdir -p /backup
be
#backup and truncate log
mysqldump -u${user} -p${pass} --events --all-databases > ${back_dir}/${back_file}
mysql -u${user} -p${pass} -e 'flush logs'
#Only keep backups from the last week
cd $ back_dir
find . -mtime +7 -exec rm -rf {} \;
Manual test:
#chmod a+x /mysql_back.sql
#chattr +i /mysql_back.sql
#/mysql_back.sql
Configure cron:
# crontab -e
2 * * * /mysql_back.sql
6. Export and import of tables
1) SELECT... INTO OUTFILE to export a text file
mysql> SELECT * FROM school.student1 INTO OUTFILE 'student1.txt'
FIELDS TERMINATED BY ',' //Define field separator
OPTIONALLY ENCLOSED BY '"' // define what symbols are used to enclose the string
LINES TERMINATED BY '\n' ; //define line break
2) The mysql command exports a text file:
mysql -u root -p123 -e 'select * from student1.school' > /tmp/student1.txt
mysql -u root -p123 --xml -e 'select * from student1.school' > /tmp/student1.xml
mysql -u root -p123 --html -e 'select * from student1.school' > /tmp/student1.html
3) LOAD DATA INFILE import text file
mysql> DELETE FROM student1;
mysql> LOAD DATA INFILE '/tmp/student1.txt' INTO TABLE school.student1
FIELDS TERMINATED BY ','
OPTIONALLY ENCLOSED BY '”'
LINES TERMINATED BY '\n';
Note: ERROR 1238 (HY000): Variable 'secure_file_priv' is a read only variable may be reported
The most important thing in the database is the data. Once the database permissions are leaked, the data can be easily exported to a file and then downloaded and taken away through the above statement. Therefore, mysql restricts this and can only export the file to the specified directory.
[mysqld]
secure_file_priv='xxx'
Restart mysql and re-execute the above statement
7. Database Migration
Make sure to migrate between the same versions
#mysqldump -h source IP -uroot -p123 --databases db1 | mysql -h destination IP -uroot -p456
3. pymysql module
1. Installation
pip3 install pymysql
2. Link, execute sql, close (cursor)
import pymysql
user=input('Username: ').strip()
pwd=input('password: ').strip()
#Link
conn=pymysql.connect(host='localhost',user='root',password='123',database='databasename',charset='utf8')
#cursor
cursor=conn.cursor() #The result set returned after execution is displayed as a tuple by default
#cursor=conn.cursor(cursor=pymysql.cursors.DictCursor)
#Execute sql statement
sql='select * from tablename where name="%s" and password="%s"' %(user,pwd) #Note that %s needs to be quoted
print(sql)
res=cursor.execute(sql) #Execute the sql statement and return the number of records for which the sql query was successful
print(res)
cursor.close()
conn.close()
if res:
print('Login successful')
else:
print('Login failed')
3. sql injection of execute()
4. Add, delete, modify: conn.commit()
5、查：fetchone，fetchmany，fetchall
6. Get the auto-incrementing ID of the last piece of data inserted