Equi join Operations
Learn the basics about equi joins in LINQ.
We'll cover the following...
Joins
A join is an association between objects of two data sources based on common attributes. In EF Core, we create relationships between objects through the navigational properties of the related entities. Therefore, we use joins to associate elements from different source sequences that do not have a direct relationship in the object model.
This illustration highlights a join between two object sets. It indicates those sets that form part of an inner join and an outer join.
Most join operations in LINQ can be categorized as either equi joins or custom joins. In this lesson, we’ll demonstrate equi joins.
Equi joins
Equi joins are joins that perform comparisons on data sources based on the equality of their keys. Equi joins do not support other conditional comparisons such as “greater than” or “not equals.” In LINQ, the join clause (query syntax), the Join, and GroupJoin methods (query methods) perform equi joins.
Inner Join
An inner join is an equi join that produces a result set in which every element of the first sequence appears once for every matching element in the second sequence. If an element in the first sequence has no matching elements, it does not appear in the result set. With query syntax, we implement an inner join using the join clause.
We demonstrate an inner join with ...