download db2

1. goto ibm website to download it
2. current version is 11.5.7.0
3. you will get a file named like v11.5.7_linuxx64_server_dec.tar.gz

install on ubuntu

1. untar package, you will get a server_dec folder
2. cd to folder cd server_dec
3. check requirements ./db2prereqcheck -v 11.5.7.0
4. should get not meet requirements, db2 require i386 arch lib
5. update ubuntu arch config sudo dpkg --add-architecture i386
6. update package index sudo apt update
7. install missing lib sudo apt install libpam0g-dev:i386 libx32stdc++6 ksh ksh93
8. check requirements ./db2prereqcheck -v 11.5.7.0
9. now you shold meet requirements
10. change to root user sudo -s
11. install db2 ./db2_install

verify

1. run ./db2ls you should get db2 install info，contains install path，version etc.
2. cd to ${install path}/adm folder
3. run ./db2licm -l you should get db2 license info

how to create db2 instance

1. first you need create a linux group and usergroupadd db2 && /usr/sbin/useradd -d /home/db2test -g db2 -s /bin/bash db2test
2. create user home folder mkdir /home/db2test && chown db2test:db2 /home/db2test
3. create db2 instance cd ${install path}/instance && ./db2icrt -u db2test db2test
4. change to db2 user to verify instance info su - db2test && db2level
5. start db2 instance db2start
6. connect to instance db2
7. now you can run sql to create database create database test

how to create table and manage data

1. connect to instance db2
2. connect to database connect to test
3. run sql to create table create table student (id integer not null, name char(50) not null,primary key(id))
4. insert data to tableinsert into student (id,name) values (1, '张三'),(2,'李四'),(3,'王麻子')
5. select data from table select * from student

tcp connect

1. first get service name db2 get dbm config, check TCP/IP Service name, that is service name
2. lookup db2 service name at /etc/services, you will get the actual tcp port
3. the default schema is actual instance uppper name, also you can check by command values current schema
4. catalog name just the node name is instance name

official document

https://www.ibm.com/docs/en/db2/11.5