DB2 database commands

There are many DB2 database commands and different functions can be implemented. The following describes some commonly used DB2 database commands in detail, hoping to give you a better understanding of DB2 database commands.

1. view the local node directory
In the command window, enter db2 list node directory.

2. cataloguing a TCP/IP Node
Command window: db2 catalog tcpip node <node_name> remote

3. Cancel node Cataloguing
Db2 uncatalog node <node_name>

4. view the system database directory
Db2 list database directory

5. view the local database directory
Db2 list database directory on <drive letter>
If the database is in the local database directory but not in the system database directory, you can right-click <database> in the control center and choose add, enter the name of the database to be added or click the refresh button to select a database. After joining the database, you can access the database.

6. cataloguing Database
Db2 catalog database <db_name> as <db_alias> at node <node_name>

7. Cancel database Cataloguing
Db2 uncatalog database <db_name>

8. Test the remote database connection.
Db2 connect to <db_alias> user <user_id> using <password>

9. Any user can set the default mode for a specific database connection by setting the Current Schema special register. The initial default value is the permission ID of the Current session user.
Set schema = <schema name>
This statement can be used interactively or in applications. If the Dynamicrules Bind option is used to Bind a package, this statement does not work. This statement is not under transaction control.

10. code page settings
Set character sets when creating databases
Create database <db_name> using codeset <codeset> territory <territiry>
Example:
Create database dbtest using codeset IBM-437 territory US
You can also set the code page of the entire database. In win2000/NT/xp, add the variable DB2CODEPAGE = <codepage> to my computer --> properties --> advanced --> environment variable, for example, DB2CODEPAGE = 437 or DB2CODEPAGE = 1386. Alternatively, enter db2set DB2CODEPAGE = 1386 in the IBM DB2 command window. After the settings, restart DB2 to take effect.

11. migration of data from earlier DB2 versions to later versions
First, import the data backup of earlier versions to the database of later versions using the restoration function, and then enter db2 migrate database <db_name> in the Command window.

12. Access the table when the table name or mode contains quotation marks
Command window: db2 select * from \ "tabschema \". \ "tabname \"
Command Line processor: db2 => select * from "tabschema". "tabname"

13. Export the table structure of the database to generate the DDL File
Command window: db2look-d <db_name>-e-c-o <file_name>

14. Execute the script file
Command window: db2-tvf <file_name>

15. Code Page Conversion

16. Obtain the current DB2 version
Select * from sysibm. sysversions

17. Restrictions on modifying fields in the DB2 table?
Only the VARCHAR2 type can be modified and can be increased or not decreased.
Alter table <tb_name> alter column <col_name> set data type varchar (SIZE)

18. How to view the table structure?
Describe table <tb_name>
Or
Describe select * from <schema>. <tb_name>

19. How to quickly clear a large table?
Alter table TABLE_NAME ACTIVE NOT LOGGED INITALLY WITH EMPTY TABLE

20. How can I view the stored procedures of a database?
SELECT * from syscat. PROCEDURES

21. How to view table constraints?
SELECT * from syscat. checks where tabname = <tb_name>

22. How do I view the complete reference constraints of a table?
SELECT * from syscat. references where tabname = <tb_name>

23. How do I know the BUFFERPOOLS status?
Select * from SYSCAT. BUFFERPOOLS

24. How can I view and modify instance and database configuration parameters in the command line?
View instance configuration parameters: db2 get dbm cfg
Modify instance configuration parameters: db2 update dbm cfg using parameter name New Value

View database configuration parameters: db2 get db cfg for <db_name>
Modify database configuration parameters: New Value of db2 update db cfg for <db_name> using parameter name

25. How to modify the buffer?
Add a buffer: create bufferpool <buf_name> size <number of pages> [pagesize 4096] {[not] extended storage}
Modify the buffer: alter bufferpool <buf_name> size <number of pages> {[not] extended storage}
Delete a buffer: drop bufferpool <buf_name>

If the buffer size is set to-1, the number of pages of the buffer pool is determined by the buffpage parameter configured by the database.
Note: The Database Configuration Parameter buffpage only applies to the buffer pool with the buffer size set to-1.

26. How to Use in/not in without using the select clause when multiple fields exist?
Select * from tabschema. tabname where (colA, colB, colC) [not] in (valueA1, valueB1, valueC1), (valueA2, valueB2, valueC2 ),... (valueAn, valueBn, valueCn ))

27. view the applications currently connected to the database
Db2 list application [show detail]

28. How to confirm the consistency of the DB2 database
Db2dart <db_name>/DB
/DB indicates checking the consistency of the entire database

29. test the performance of SQL statements
Db2batch-d <db_name>-f <file_name> [-a userid/passwd] [-r <outfile_name>]
-R indicates that the query result is output to a file.
30. Export the data of a table
Export to <Derectry> <filme>
For example, export a user table.
Export to c: \ user. ixf of ixf select * from user

31. Import Data
Import from
For example, import a user table. You can create a new table directly during import. If the table exists, you can use INSERT or UPDATE.

Connect to 31 to import data
Execute import: import from c: \ user. ixf of ixf [Create/Insert into/update] tablename

32. query the lock table
Select * from table (snapshot_lock ('ssfx ',-1) as lock
 

Four file formats for DB2 data movement

Implementation of Online DB2 backup

How to Create a DB2 instance in Windows

DB2 Time Functions

DB2 common table expression usage