How can you tell if a table in DB2 has a Primary Key?

Disclaimer: I do not know DB2.

I simply googled these with "db2 table definition".

Source:

SELECT * 
FROM SYSIBM.SYSTABLES TAB,SYSIBM.SYSCOLUMNS COL 
WHERE TAB.CREATOR = COL.TBCREATOR 
AND TAB.CREATOR = 'xxxx' 
AND TAB.NAME = 'xxxxxxxxxxxxx' 
AND TAB.NAME = COL.TBNAME 
AND TAB.TYPE = 'V' ( OR 'T' ) 
ORDER BY 1,2;

Source:

SELECT * FROM syscat.tabconst WHERE type = 'P';

you can do a db2look, which will give you the ddls for the table.

db2look -d db_name -e -x -z schema_name -t table_name