What is meant by binary relationship and general relationship?

Binary Relationship 

A data structure diagram that links only two record types is called a binary relationship. This is similar to the binary relationship of the E-R diagram.

Binary relationships are basically of 3 types, viz--

(i) One to One

(ii) One to Many and

(iii) Many to many.

If the binary relationship is One to One then the arrow keys will be on either side of the link. But if the relationship is One to Many or Many to One, then either side of the link will have its mark on one side.

 

General Relationship:

Basically, the relationship method that establishes the relationship between more than two records is called general relationship. General relationships are usually shown by boxes and links. For example, consider an E-R diagram made up of three entities, Customer, Account and Branch, which are related to the general relationship CAB.

 E-R diagram to show general relationships of network data model Data Structure Diagram following steps should be taken:

(i) Entity Set Customer, Account and Branch should be related by Record Type Account, Customer I Branch.

(ii) A new record type and link should be created, which may have no field or single field with Unique Identifier.

(iii) The following Many to One links should be created:

(a) Create Cust R link from R link to Customer Record. 

b) Create Acct R link from R link to Customer Record.

(c) Brn R link should be created from R link to Customer Record.