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Workbench and Identifying and non Identifing Relationships
Posted by: Pete Watters
Date: October 01, 2017 12:43PM

I am attempting to understand the differences between non identifying and identifying relationships and how they work and when to use one over the other.

It seems that it is the database desingers option to select one or the other but the questions is why one over the other.

Have a "MANUFACTURE" table Primary key mfg-id-sys varchar(20) that is the Parent to "MATERIAL" table where primary key is compound

mfg_id_sys varchar(20)
material_Part_num varchar(100)

For a "MANUFACTURE" table row there can be many entries in the "MATERIAL" table

If i make the relationship identifing it creates a new compound primary key by recreating the origional compound Primary key and adds
"Manufacture_mfg_id_sys, varchar(20) to the new compound primary key
mfg_id_sys varchar(20)
Manufacture_mfg_id_sys varchar(20)
material_Part_num varchar(100)

But the origional compound primary key remains

mfg_id_sys varchar(20)
material_Part_num varchar(100)

Should I delete the origional Primary key since I can have only one?
Uncheck the primary option on the origional compound primary key?
is this a good idea to use identifing relationships.

I

If I make it a non-identfying relationship is just adds

mfg_id_sys varchar(20)
Manufacture_mfg_id_sys varchar(20)
material_Part_num varchar(100)
as foreign keys

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