relationship type,degree, cardinality, optionality terms confusion

Ok here is the explanation

1.Degree. This is the number of entities involved in the relationship and it is usually 2 (binary relationship) however Unary and higher degree relationships can be exists.

2.Cardinality. This specifies the number of each entity that is involved in the relationship there are 3 types of cardinality for binary relationships

• one to one (1:1)
• one to many (1:n)
• many to many (n:m)

hope this will clear your mind. Please communicate for more information

Degree - number of attributes (columns) in a relation (table)

Cardinality - number of tuples (rows) present in a table

See this for more details.

To add to the first answer: Simply

Degree of a Relation - Number of attributes in a relation Cardinality of a Relation - Number of tuples in a relation.

Can't post the image to show you but you can check out this book to read up more and get a better picture. Also there is Connolly and Begg - Database Systems, 4th Edition Reference:

Elmasri, R., Navathe, S.B., 2011. Fundamentals of Database Systems. 6th ed. United States of America: Pearson.

Degree of a Relationship : The number of participating entities in a relationship. This can be unary, binary, ternary, quaternary, etc

Cardinality : The number of relationship instances an entity can participate in. Ex: 1:1, 1:Many, Many:N

(Min,Max) notation : Minimum represents the participation constraints while Maximum stands for the cardinality ratio.

Degree of a relation : Number of columns(attributes) in a relation(table).