What does o2m, m2o, m2m stands for?

Question

While reading documentation or code comments, one may meet terms o2m, m2o, m2m. What do they stand for?

Also what do they mean?

Answer 1

They are abbreviations of cardinalities used in data modeling for:

• one to many
• many to one
• many to many

So obviously one may also encounter o2o for one to one relations.

Answer 2

You could also have O2O:

• One-to-One (O2O)
• One-to-Many (O2M)
• Many-to-One (M2O)
• Many-to-Many (M2M)

List of Technology Acronyms