Fetching rows in DB2

问题:

I know in DB2 (using version 9.7) I can select the first 10 rows of a table by using this query:

SELECT * 
FROM myTable
ORDER BY id
FETCH FIRST 10 ROWS ONLY

But how can I get, for example, rows 11 to 20? I can't use the primary key or the ID to help me...

Thanks in advance!

回答1:

Here's a sample query that will get rows from a table contain state names, abbreviations, etc.

SELECT *
FROM (
   SELECT stabr, stname, ROW_NUMBER() OVER(ORDER BY stname) AS rownumber
   FROM states
   WHERE stcnab = 'US'
) AS xxx
WHERE rownumber BETWEEN 11 AND 20 ORDER BY stname

Edit: ORDER BY is necessary to guarantee that the row numbering is consistent between executions of the query.

回答2:

You can also use the MYSQL compatibility. You just need to activate the vector compatibility for MYS, and then use Limit and Offset in your queries.

db2set DB2_COMPATIBILITY_VECTOR=MYS
db2stop
db2start

• An excellent article written by DB2 experts from IBM https://www.ibm.com/developerworks/mydeveloperworks/blogs/SQLTips4DB2LUW/entry/limit_offset?lang=en
• Compatibility vector in InfoCenter http://publib.boulder.ibm.com/infocenter/db2luw/v10r1/topic/com.ibm.db2.luw.apdv.porting.doc/doc/r0052867.html
• A blog about this http://victorsergienko.com/db2-supports-limit-and-offset/