zaster
zaster

Reputation: 421

Table Structure Issue - Many to Many

dispatches 1------M dispatch_items

sub_jobs 1-------M dispatch_items

dispatches M-----N sub_jobs

I need to have all of these relationships

dispatch_subjob table (Is the intermediary table between dispatches and sub_jobs) and it has below mentioned columns

id
dispatch_id
sub_job_id

dispatch_items tablehas below mentioned columns

id
dispatch_id
sub_job_id
qty
description

My issue is that i see dispatch_id and sub_job_id is repeated in both tables(Table structure looks wrong)

Practically i need to have both these tables like above mentioned to get results in a much practical way

E.g.: - sub_jobs table has a qty field and i need to do some caculations with dispatch_items table qty (Use of 1 to M)

E.g.:- I need to get all sub_jobs of when a dispatch_id is given (Use of M to M)

Upvotes: 0

Views: 28

Answers (1)

Drewster
Drewster

Reputation: 539

It looks like your dispatch_items and dispatch_subjob tables are performing the same role, as a pivot between the two. If that's the case, dispatch_subjob is not necessary as you have the additional cols on dispatch_item (although it's probably more correct naming to keep dispatch_subjob).

Upvotes: 1

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