Mysql_frequently_used_commands

Wed, 22 Sep 2021 10:39:22 +0800

###Note for frequently used sql commands, just in case forget when long time don’t use it

let’s say you want a below table:

#	name_of column	type	length	can empty	master key
1	id	int	12	no	yes
2	topic	varchar	255	no	no
3	content	longtext		yes	no
4	tag	varchar	255	yes	no
5	insert_time	datetime		yes	no

to create above table:

CREATE TABLE IF NOT EXISTS `mq_info` ( 
 `id` INT(12) UNSIGNED AUTO_INCREMENT COMMENT 'auto increase id',
 `topic` VARCHAR ( 255 ) NOT NULL COMMENT 'topic name', 
 `content` longtext NOT NULL COMMENT 'content', 
 `tag` VARCHAR ( 255 ) COMMENT 'tag of this Message Queue', 
 PRIMARY KEY ( `id` ) 
) ENGINE = INNODB DEFAULT CHARSET = utf8;

Query all data in table:

Mysql_installation

Sun, 07 Feb 2021 18:33:58 +0800

The general view of the difference between mysql and marinaDB can refer to this link:

https://blog.panoply.io/a-comparative-vmariadb-vs-mysql

And I quote some here:

MySQL: MySQL is an open-source relational database management system (RDBMS). Just like all other relational databases, MySQL uses tables, constraints, triggers, roles, stored procedures and views as the core components that you work with. A table consists of rows, and each row contains a same set of columns. MySQL uses primary keys to uniquely identify each row (a.k.a record) in a table, and foreign keys to assure the referential integrity between two related tables.

Python_mysql

Sun, 07 Feb 2021 13:21:07 +0800

Python Query mysql

To use Python to query mysql DB. There are two popular modules are used:

pymysql
sqlalchemy ( need to install mysqlconnector in my scenario) pip install mysql-connector-python

pymysql:

ekoudb = pymysql.connect(host='10.10.80.127', 
 port=3306, 
 user='ekou', 
 password='abcd12334', 
 database='ekoutest') 
 
 #get cursor 
cursor = ekoudb.cursor()

def insert_a_item(SqlLang): 
 """ 
 Insert items """ 
 try: 
 cursor.execute(SqlLang) 
 ekoudb.commit() 
 except Exception as e: 
 print('Insert data fail') 
 print(e) 
 ekoudb.rollback() 
 # release resource 
 cursor.close() 
 ekoudb.close() 
#insert_a_item(SQL_INSERT_A_ITEM)
SQL_INSERT_MANY_ITEMS = "INSERT INTO bird_table (origin, hostname,descr,ver,protocol,neighboraddr,neighboras,status,sinceday,sincetime) VALUES(%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)"

MULTIENTRY = [["update","host1","descr1","ipv6","BGP","2123123","231233","Idle","2021-02-02","16:50:07"],\ 
["update","host2","descr2","ipv6","BGP","ipv6_addr1","65300","Idle","2021-02-02","16:50:07"],\ 
["update","host3","descr3","ipv4","BGP","10.10.1.1","65002","Established","2021-02-02","15:50:13"],\ 
["update","host4","descr4","ipv4","BGP","10.10.1.3","65003","Established","2021-02-02","15:50:13"]]

def insert_items(MANYTIMESFORMAT,SqlLang): 
 try: 
 cursor.executemany(MANYTIMESFORMAT, SqlLang) 
 ekoudb.commit() 
 except Exception as e: 
 print("Insert_error") 
 ekoudb.rollback() 
 # release resource 
 cursor.close() 
 ekoudb.close()

def query(SqlLang): 
 """query""" 
 # query all data 
 cursor.execute(SqlLang) 
 print('+--------+-----------+---------------------------+------+----------+-\ 
-------------------------+------------+-------------+------------+-----------+') 
 print('| origin | hostname | descr | ver | protocol | \ 
 neighboraddr | neighboras | status | sinceday | sincetime |') 
 print('+--------+-----------+---------------------------+------+----------+-\ 
-------------------------+------------+-------------+------------+-----------+') 
 # matrix data 
 rows = cursor.fetchall() 
 for row in rows: 
 origin = row[0] 
 hostname = row[1] 
 descr = row[2] 
 ver = row[3] 
 protocol = row[4] 
 neighboraddr = str(row[5]) 
 neighboras = str(row[6]) 
 status = row[7] 
 sinceday = str(row[7]) 
 sincetime = str(row[9]) 
 
# print('| ' + origin.rjust(2) + '|'.rjust(7) + hostname.rjust(2) + '|'.rjust(10) + descr.rjust(2) + '|'.rjust(26) + ver.rjust(2) + '|'.rjust(5) + protocol.rjust(2) + '|'.rjust(9) + neighboraddr.rjust(2) + + '|'.rjust(25) + neighboras.rjust(2) + '|'.rjust(11) + status.rjust(2) + '|'.rjust(12) + sinceday.rjust(2) + '|'.rjust(11) + sincetime.rjust(2)) 
# print('| ' + origin.rjust(2) + '\t|' + '\t' + hostname + '\t|' + '\t'+ descr + '\t|' + '\t' + ver + '\t|' + '\t' + protocol + '\t|'+'\t'+neighboras + '\t|'+'\t'+neighboraddr + '\t|'+'\t'+status + '\t|'+ '\t' + sinceday + '\t|'+ '\t' +sincetime + '\t|') 
 print('|' + format(origin,"<8") + format("|","<2") + format(hostname,"<10") + format("|","<2") + format(descr,"<26") + format("|","<2") + format(ver,"<5") + format("|","<2") + format(protocol,"<9") + format("|","<2") + format(neighboraddr,"<25") + format("|","<2") + format(neighboras,"<11") + format("|","<2") + format(status,"<12") + format("|","<2") + format(sinceday,"<11") + format("|","<2") + format(sincetime,"<10") + "|" ) 
 print('+--------+-----------+---------------------------+------+----------+-\ 
-------------------------+------------+-------------+------------+-----------+') 
 # release resource 
 cursor.close() 
 ekoudb.close()
 


SQL_UPDATE = "UPDATE bird_table SET hostname='%s',status='%s' WHERE descr='%s'" 
 
def update(SqlLang): 
 """ 
 update 
 :return: """ sql_update = SqlLang % ('hostname3', 'connect', 'descr_1') 
 try: 
 cursor.execute(sql_update) 
 ekoudb.commit() 
 except Exception as e: 
 ekoudb.rollback() 
 print('error when update data') 
 print(e) 
 # release resource 
 cursor.close() 
 ekoudb.close() 
 
update(SQL_UPDATE)
SQL_DELETE = "DELETE FROM bird_table WHERE descr='%s'" 
 
def delete(SqlLang,delete_string): 
 """ 
 delete record 
 :return: """ try: 
 # delete sql 
 sql_del = SqlLang % (delete_string) 
 cursor.execute(sql_del) 
 ekoudb.commit() 
 except Exception as e: 
 # rollback when error 
 ekoudb.rollback() 
 print(e) 
 # release resource 
 cursor.close() 
 ekoudb.close() 
 
delete(SQL_DELETE,'23123213213')

sqlalchemy:

engine = create_engine("mysql+mysqlconnector://ekou:PASSWORD@10.10.80.127:3306/ekoutest?charset=utf8mb4")

metadata = MetaData(engine) 
 
Session = sessionmaker() # create a customized session 
Session.configure(bind=engine) # link to this session 
session = Session()
users_table = Table('bird_table', metadata, autoload=True)

result=users_table.select(and_(users_table.c.descr == "descr", users_table.c.neighboraddr == "NEIGHBOR_ADDR")).execute() 
for item in result.fetchall(): 
 print (item)

''' 
create table 
''' 
users_table = Table('users', 
 metadata, 
 Column('id', Integer, primary_key=True), 
 Column('name', String(40)), 
 Column('email', String(120))) 
if not users_table.exists(): 
 users_table.create() 
 
''' 
load table 
''' 
users_table = Table('users', metadata, autoload=True) 
 
''' 
insert 
''' 
users_table.insert().execute(name="sss", email="eee@eee.com") 
users_table.insert().execute(name="ttt", email="tt@eee.com") 
''' 
update 
''' 
users_table.update(users_table.c.name == "ttt").execute(name="ddd")

conclusion:

for easier get on hand, pymsql would be good enough to use. but for advanced, need to use sqlalchemy.