Getting Primary key associated with Tables.

select tab.table_name,col.column_name  
from 
    information_schema.table_constraints tab,  
    information_schema.constraint_column_usage col  
where  
    col.constraint_name = tab.constraint_name 
    and col.table_name = tab.table_name 
    and constraint_type = 'primary key' 
order by tab.table_name;