I suspect you hit the central problem square on the head.   And, just for completeness:   you can also represent many-to-many relationships in an SQL database ... this requires three tables.   For example:
INVOICE <-> INVOICE_LINEITEMS <-> ITEMS.


In reply to Re^2: access array of values without a loop by sundialsvc4
in thread access array of values without a loop by spie287

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