Question

I have to add many registries to a table and I need help since I am starting to work with PL/SQL

I have a table with three columns (ID, KEY, VALUE). The ID & KEY has to be unique, and if there is not a value for a KEY called ‘process_name’ is have to create a new registry where the value has to be the same as the ID.

for example, I could have this in my table

ID      KEY            VALUE
A       cycles           4  
A       process_name     A
A       number           2
B       cycles           3
B       number           2
C       cycles           5

So, I would need to insert 2 records to the DB:

B      process_name       B
C      process_name       C

How should I start creating the script?

Thanks

SOLUTION

INSERT INTO my_table
   (SELECT distinct my_table.ID, 'process_name', my_table.ID
      FROM my_table
      WHERE my_table.ID NOT IN (SELECT distinct my_table.ID
                                 FROM my_table
                                 WHERE key = 'process_name'));  

Answer 1

Assuming distinct_id is not nullable, you could use:

INSERT INTO your_table 
   (SELECT distinct id, 'process_name', id
      FROM your_table
     WHERE distinct_id NOT IN (SELECT distinct_id 
                                 FROM your_table
                                WHERE key = 'process_name'));

If distinct_id is nullable, use NOT EXISTS instead:

INSERT INTO your_table 
   (SELECT distinct id, 'process_name', id
      FROM your_table t_out
     WHERE NOT EXISTS (SELECT NULL
                         FROM your_table t_in
                        WHERE t_in.id = t_out.id
                          AND t_in.key = 'process_name'));