3 votes 3 votes What is the relationship between strong entity and weak entity 1:1 1:M M:1 M:N Please explain ? Databases er-diagram databases + – sunaina rawat asked Dec 2, 2017 sunaina rawat 646 views answer comment Share Follow See 1 comment See all 1 1 comment reply smsubham commented Jan 14, 2018 reply Follow Share Selected answer is wrong. Check this by Arjun sir https://gateoverflow.in/14043/what-is-the-relationship-between-weak-and-strong-entity 0 votes 0 votes Please log in or register to add a comment.
Best answer 1 votes 1 votes An entity set that does not have a primary key is referred to as a weak entity set. so the existence of a weak entity set depends on the existence of a strong entity set so it should have one to many relationship. Red_devil answered Dec 2, 2017 selected Dec 2, 2017 by joshi_nitish Red_devil comment Share Follow See all 2 Comments See all 2 2 Comments reply sunaina rawat commented Dec 2, 2017 reply Follow Share Please explain why not many to many I am not getting. Also please check https://gateoverflow.in/14043/what-is-the-relationship-between-weak-and-strong-entity 0 votes 0 votes Red_devil commented Dec 2, 2017 reply Follow Share see weak entity can not be identified by there own attribute so they need a strong entity by which they can be discriminated. Ex: suppose there are two table employee table and dependent table a employee has employee id as the primary key but dependent table has no primary key so many dependent can be related to same employee id but you can not relate two employee to same dependent. so it is one to many i.e a strong entity can have many dependent(weak entity) 0 votes 0 votes Please log in or register to add a comment.