I have a SQL dump file. There are many tables, one of which contains a column I would like to set to null before final archiving.

The dump file has a structure like:

```
COPY public.my_target_table (id, name, content_type_id, codename) FROM stdin;
1   Can add association 1   add_association
2   Can change association  1   change_association
<..................>

COPY public.table_2 (id, name, content_type_id, codename) FROM stdin;
1   Can add association 1   add_association
2   Can change association  1   change_association

```

The values are tab-separated. My initial idea was to `sed` find/replace between the appropriate indices, but I realized I will need to only do so for one specific table (otherwise I am wiping data from all tables, at that index).

Is there a way to tell `sed` to only operate once it has passed the string `my_target_table`, and disable when it has reached the next blank line?

*edit for clarity*

Using the example above, the goal is to output:

```
COPY public.my_target_table (id, name, content_type_id, codename) FROM stdin;
1   \N  1   add_association
2   \N  1   change_association
<..................>

COPY public.table_2 (id, name, content_type_id, codename) FROM stdin;
1   Can add association 1   add_association
2   Can change association  1   change_association

```

...assuming my memory is correct and `\N` means null. Ideally the answer can be extended to any target table and column index (or even better, target table and column name :) ). Also, I'm not limited to `sed` - I have heard `awk` might be a useful tool here as well?