update, delete or replace?

[Anon]

Advice please:

I have records kept in table 1. Categories in table 3 and a linking table (table2).

The idea is that one record can have many categories.

If i want to update the categories for a chosen record, and I want to reduce the number of categories associated to it. Is it ok just to update? What happens to the now missing record as there will now be nothing in it? Is it better to delete all categories for that record and then re-insert them?

Any advice appreciated

[tomhath]

Which table(s) are you talking about updating? I read this question and ask myself - huh?

"What happens to the now missing record as there will now be nothing in it?"

[Anon]

Sorry about the confusion, hope this can clear things up a little:

table 1(soluiton):
sid, timestamp, title, problem, solution, cid, hit
table 2(solcat):
scid, sid, cid
table 3(category):
cid, category

Relationship table 1 to 2 (1 to Many)
Relationship table 3 to 2 (1 to many)
Hope this helps.

The problem is that a record in table 1 can have many associated entries in table 2.

There are two similar questions now i think about it.
1. If I want to update the values in solcat
should i use update?, replace? or delete & insert?
2. What if I want to either increase or decrease the number of entries in solcat for a given record in solution. Wont I either have gaps? or have performance problems as the data gets spread throughout solcat?

Hope that clears things up a little.