如何在DOCKER環境中使用Db2
前言
此問的目的是幫助用戶能夠在docker的環境中學習Db2，前提條件的你的服務器可以訪問互聯網，否則無法下載Db2鏡像。Docker環境中學習Db2的優勢是省去了下載產品、安裝產品、初始化數據庫實例這部分工作，更適合於開發人員學習Db2。
另外本文也介紹了Db2和MYSQL的常用命令區別，以便於大家同時學習兩個產品。
1、列出已有的Db2鏡像
-bash-4.2# docker images | grep -i db2
ibmcom/db2express-c latest 7aa154d9b73c 2 years ago 1.71 GB
2、拉Db2鏡像
-bash-4.2# docker pull ibmcom/db2express-c
Using default tag: latest
latest: Pulling from ibmcom/db2express-c
a3ed95caeb02: Pull complete
aeb4552c46f2: Pull complete
67f42aa337c8: Pull complete
36add9e32b7b: Pull complete
cca79fe4efc9: Pull complete
47257c26990b: Pull complete
ffaad03725df: Pull complete
12bf772a460f: Pull complete
d7696ccb610d: Pull complete
6cf81245c65d: Pull complete
5dab63ce98e0: Pull complete
91dd2d768d97: Pull complete
e3aca141cf3e: Pull complete
Digest:sha256:6217d60b20b58e08e5189f467cfb9a08f3472cf6c3a5e5d5d91900791c709a86
Status: Downloaded newer image foribmcom/db2express-c:latest
3、啟動容器：
-bash-4.2# docker run -it --network=host -p50000:50000 -e DB2INST1_PASSWORD=db2inst1-pwd -e LICENSE=accept ibmcom/db2express-c:latest bash
Changing password for user db2inst1.
New password: BAD PASSWORD: The passwordcontains the user name in some form
Retype new password: passwd: allauthentication tokens updated successfully.
- -p 50000:50000 允許遠程的客戶端可以從50000 端口連接到數據庫實例.
- 通過指定 -e DB2INST1_PASSWORD=db2inst1-pwd 參數, 你可以為缺省的Db2實例用戶db2inst1設置密碼.
- 通過指定-e LICENSE=accept參數, 表示你接受了使用Db2軟件的許可證協議.
4、切換到實例用戶db2inst1
[root@shcallisto-25 /]# su - db2inst1
Last login: Wed May 20 21:57:28 UTC 2015
5、啟動實例
[db2inst1@shcallisto-25 ~]$ db2start
SQL1063N DB2START processing was successful.
6、查看運行狀態
[db2inst1@shcallisto-25 ~]$ db2pd -
Database Member 0 -- Active -- Up 0 days00:00:06 -- Date 2018-01-16-03.30.51.059168
7、查看已經創建的數據庫
[db2inst1@shcallisto-25 ~]$ db2 list dbdirectory
SQL1031N The database directory cannot be found on the indicated file system.
SQLSTATE=58031
說明目前沒有創建數據庫
8、查看數據庫和補丁版本
[db2inst1@shcallisto-25 ~]$ db2level
DB21085I This instance or install (instance name, where applicable:
"db2inst1") uses "64"bits and DB2 code release "SQL10055" with level
identifier "0606010E".
Informational tokens are "DB2v10.5.0.5", "s141128", "IP23633", and Fix Pack
"5".
Product is installed at"/home/db2inst1/sqllib".
9、顯示運行的Db2容器信息,在宿主機上運行
-bash-4.2# docker ps | grep db2
3492501e4f07 ibmcom/db2express-c:latest "/entrypoint.sh bash" 16 seconds ago Up 15 seconds wizardly_mestorf
10、關閉數據庫實例，后面需要啟動容器時指定宿主機目錄和容器目錄的映射關系，目的是在這些目錄中創建數據庫。
db2stop
exit
11、重啟容器，通過-v選項指定宿主機目錄和容器目錄的映射關系：
-bash-4.2# docker run -it --network=host -p50000:50000 -e DB2INST1_PASSWORD=db2inst1-pwd -e LICENSE=accept -v /db2data:/db2data ibmcom/db2express-c:latest bash
Changing password for user db2inst1.
New password: BAD PASSWORD: The passwordcontains the user name in some form
Retype new password: passwd: allauthentication tokens updated successfully.
宿主機目錄為/db2data，容器目錄為/db2data
12、[root@shcallisto-25/]# df -h
Filesystem Size Used Avail Use% Mounted on
rootfs 148G 55G 94G 37% /
overlay 148G 55G 94G 37% /
tmpfs 7.9G 0 7.9G 0% /dev
tmpfs 7.9G 0 7.9G 0% /sys/fs/cgroup
/dev/mapper/rhel-root 148G 55G 94G 37% /db2data
shm 64M 0 64M 0% /dev/shm
13、設置目錄權限，其中db2data為表空間的目錄、log為日志目錄、dbpath為創建數據庫時的dbpath。
[root@shcallisto-25 /]# chmod 777 db2data
[root@shcallisto-25 /]# su - db2inst1
Last login: Tue Jan 16 05:15:10 UTC 2018 onconsole
[db2inst1@shcallisto-25 ~]$
[db2inst1@shcallisto-25 ~]$ cd /db2data
[db2inst1@shcallisto-25 db2data]$ touch 1
[db2inst1@shcallisto-25 db2data]$ rm 1
[db2inst1@shcallisto-25 db2data]$ mkdirdata
[db2inst1@shcallisto-25 db2data]$ mkdir dbpath
[db2inst1@shcallisto-25 db2data]$ mkdir log
[db2inst1@shcallisto-25 db2data]$ pwd
/db2data
[db2inst1@shcallisto-25 db2data]$ ls -lrt
total 0
drwxrwxr-x 2 db2inst1 db2inst1 6 Jan 1605:16 data
drwxrwxr-x 2 db2inst1 db2inst1 6 Jan 1605:16 dbpath
drwxrwxr-x 2 db2inst1 db2inst1 6 Jan 1605:16 log
查看缺省的dbpath
[db2inst1@shcallisto-25 ~]$ db2 get dbm cfg| grep -i dbpath
Default database path (DFTDBPATH) =/home/db2inst1
14、創建用戶數據庫mydb
[db2inst1@shcallisto-25 db2data]$db2start
[db2inst1@shcallisto-25 db2data]$ db2 "create db mydb on /db2data/data dbpath on /db2data/dbpath using codeset utf-8 territory cn"
DB20000I The CREATE DATABASE command completed successfully.
15、修改日志路徑
[db2inst1@shcallisto-25 db2data]$ db2 update db cfg for mydb using newlogpath /db2data/log
DB20000I The UPDATE DATABASE CONFIGURATION command completed successfully.
16、激活數據庫
[db2inst1@shcallisto-25 db2data]$ db2activate db mydb
DB20000I The ACTIVATE DATABASE command completed successfully.
17、確認日志生效
[db2inst1@shcallisto-25 db2data]$ cd /db2data/log
[db2inst1@shcallisto-25 log]$ ls
NODE0000
[db2inst1@shcallisto-25 log]$ cd *
[db2inst1@shcallisto-25 NODE0000]$ ls
LOGSTREAM0000
[db2inst1@shcallisto-25 NODE0000]$ cd *
[db2inst1@shcallisto-25 LOGSTREAM0000]$ ls
S0000000.LOG S0000001.LOG S0000002.LOG SQLLPATH.TAG
[db2inst1@shcallisto-25 LOGSTREAM0000]$ ls-lrt
total 12028
-rw------- 1 db2inst1 db2inst1 512 Jan 16 05:22 SQLLPATH.TAG
-rw------- 1 db2inst1 db2inst1 4104192 Jan16 05:22 S0000002.LOG
-rw------- 1 db2inst1 db2inst1 4104192 Jan16 05:22 S0000001.LOG
-rw------- 1 db2inst1 db2inst1 4104192 Jan16 05:22 S0000000.LOG
[db2inst1@shcallisto-25 LOGSTREAM0000]$ db2get db cfg for mydb | grep -i primary
Number of primary log files (LOGPRIMARY) = 3
18、由於容器是靜態的，所以每次重啟容器之后都需要做catalog，否則無法訪問數據庫。
[db2inst1@shcallisto-25 sqllib]$ db2 catalog db mydb as mydb on /db2data/dbpath
DB20000I The CATALOG DATABASE command completed successfully.
[db2inst1@shcallisto-25 sqllib]$ db2connect to mydb
Database Connection Information
Database server = DB2/LINUXX8664 10.5.5
SQLauthorization ID = DB2INST1
Local database alias = MYDB
此時我們運行docker ps -a將看到有兩個Db2容器在運行：
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
3d221e0aaa69 ibmcom/db2express-c:latest "/entrypoint.sh bash" About a minute ago Up About aminute tender_fermat
088dc03e36c4 ibmcom/db2express-c:latest "/entrypoint.sh bash" 2 hours ago Up 2 hours kind_dijkstra
19、 現在，可以提交修改到容器。
docker commit 3d221e0aaa69 ibmcom/db2express-c-new
sha256:93ab907a65196dfbeba0b376b0f3bd61d8bf07e9020b80f2c72fefb80a143028
-bash-4.2# docker images | grep db2
REPOSITORY TAG IMAGE ID CREATED SIZE
ibmcom/db2express-c-new latest 93ab907a6519 About a minute ago 1.71 GB
ibmcom/db2express-c latest 7aa154d9b73c 2 years ago 1.71 GB
20、執行save命令持久化鏡像，這里運行的目的是保存catalog db的信息，以便每次重啟容器后可以直接訪問mydb數據庫
# docker save ibmcom/db2express-c-new>/home/ibm-db2express-c-new.tar
最后的結果是生成一個1.7GB大小的Tar文件
-bash-4.2# ls -l
total 1694560
-rw-r--r-- 1 root root 1735228928 Jan 16 08:02 ibm-db2express-c-new.tar
21、停止已經啟動的db2container，以避免表空間訪問沖突；
-bash-4.2# dockerps -a | more
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c33d4f38ac17 ibmcom/db2express-c-new:latest "/entrypoint.sh bash" 16 minutes ago Up 16 minutes eager_ride
3d221e0aaa69 ibmcom/db2express-c:latest "/entrypoint.sh bash" 40 minutes ago Exited (0) 16 minutes ago tender_fermat
088dc03e36c4 ibmcom/db2express-c:latest "/entrypoint.sh bash" 2 hours ago Up 2 hours kind_dijkst
-bash-4.2# docker stop 088dc03e36c4
088dc03e36c4
-bash-4.2# docker stop c33d4f38ac17
c33d4f38ac17
22、重新啟動新的image，發現不需要做catalog db了，說明這些信息已經持久化到影像中了。
-bash-4.2# docker run -it --network=host -p50000:50000 -e DB2INST1_PASSWORD=db2inst1-pwd -e LICENSE=accept -v/db2data:/db2data ibmcom/db2express-c-new:latest bash
Changing password for user db2inst1.
New password: BAD PASSWORD: The passwordcontains the user name in some form
Retype new password: passwd: all authenticationtokens updated successfully.
[root@shcallisto-25 /]#
[root@shcallisto-25 /]# su - db2inst1
Last login: Tue Jan 16 07:42:24 UTC 2018 onconsole
[db2inst1@shcallisto-25 ~]$
[db2inst1@shcallisto-25 ~]$ db2start
SQL1063N DB2START processing was successful.
[db2inst1@shcallisto-25 ~]$ db2 connect tomydb
Database Connection Information
Database server = DB2/LINUXX8664 10.5.5
SQLauthorization ID = DB2INST1
Local database alias = MYDB
23、Db2和mysql常用SQL對比
1)查看有哪些數據庫：
Db2: list db directory
mysql: show databases
2)查看有哪些用戶表
Db2:list tables 后者list tables for schema devuser
mysql: show tables
3)查看表結構
Db2:describe table table_name
mysql:describe table_name
4）取前n行數據
Db2:select * from table_name fetch first nrows only
mysql:select * from table_name limit n
5) 顯示數據庫版本
Db2: db2level 顯示db2的版本號
mysql:select version()
6)連接數據庫
Db2:db2 connect to dbname user <user_name>using <passwd>
mysql:use database
7)顯示表中列的信息
Db2: describe table <table-name>
mysql: describle <table-name>
8)創建表
Db2 :create table t1(c1 int);
mysql: create table t1(c1 int);
9)創建數據庫
Db2:create db mydb using codeset utf-8territory cn
mysql:create db mydb
10)加載數據
Db2: load client from db2.txt of del insertinto table t1;
mysql: load data local infile “mysql.txt”into table t1;
11)執行文件中的sql
Db2:db2 -tvf db2.sql
mysql: source mysql.sql;
12)重命名表
Db2: rename table t1 to t2
mysql: alter table t1 rename t2
13）創建索引
Db2: create index index_name on table_name(column_name)
mysql: create index index_name ontable_name (column_name)
14)刪除索引
Db2 :drop index index_name;
mysql: alter table table_name drop indexindex_name
15)查看當前時間
Db2: values (current timestamp)
mysql: select now()
16)導出表結構
Db2: db2look -d mydb -t test -e -o test.sql
mysql:mysqldump -uroot -pdbpasswd -d dbnametest>db.sql
作者：陸川
轉自:http://blog.csdn.net/qq_39154147/article/details/79219414