For the sake of simplicity in explaining this, imagine a room full of people talking to each other. Every statement made by one person to another would be a record in this table, and all of these records have a unique ID assigned through auto-increment.
However, not everyone in this room is talking to everyone else. There's multiple conversations going on.
These conversations need to be unique amongst themselves. This would prevent a duplicate conversation ID being started, and the site collecting all statements which don't belong to that person.
Or, in graphical representation:
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| MessageID | ConvoID | Sender | Recipients | etc...
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| 1 | 1 | A | B |
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| 2 | 1 | B | A |
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| 3 | 2 | C | D |
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| 4 | 1 | A | B |
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| 5 | 2 | D | C |
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| 6 | 1 | B | E |
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| 7 | 3 | E | F |
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You can actually see the conversations that are taking place here... A talked to B (ID 1), who replied back (ID 2) at around the same time C started a new conversation (CID 2) with D (ID 3).
A finally gets back to B about something (ID 4) and D eventually response to C's earlier inquiry (ID 5). B then talks to E about the same thing he was talking with A about (CID 1) before E turns right around and connects with F to start a completely new conversation.
If this has read like the steps which occur prior to the immediate termination of an employee, it wasn't intended that way, but you're not alone.
So you can see that every DB entry has a unique ID (MessageID), but these messages need to be easily collated together.
The solution I'm seeking is something that allows the DB to create a new and unique "ConvoID". This is why we can't auto-increment, or why we can't force uniqueness on the data set. Duplicates must occur, by nature of what this column is doing, but auto-increment would do, perhaps, the exact opposite of what it is i'm seeking for.
Any help that could point me in the right direction would be significantly appreciated.
Thanks!
