Relationship Schemas and Joins in Power BI

A popular BI software named Power BI comes handy when you’re looking to scrutinize data from various sources. One remarkable feature of this tool is that you could define relationship schema for and join tables and present their information together to be utilized in your reports and analyzes.
The Relationship Schemas and Joins are the relationships you build between various tables (data sources). Relationship Schemas are usually defined on the bases of common keys between tables whereas there exist specific kinds of joins that bring data of two tables together when they’re combined by some criteria. Power Bi utilizes various schema such as Star schema and Snowflake schema.
The Star Schema contains one fact table and multiple dimension tables where fact table has transactional data in some columns and dim table store referential information of any particular entity like Products, dates etc.
There can be one to many, one to one and many to many relationships. A common type is to create relationships with the help of unique keys between the tables that would facilitate to get reports from various tables and use them in filters.
Joining table allows you to put all tables into the data model and use different joins while combine them so that you can fetch meaningful data and do some calculations with that. Here are few join operations that you can see in the Power BI -:
InnerJoin - Returns the rows that match both tables’ Join Expression (selects rows that have same values in the both table).
Left OuterJoin - Returns all rows from the first (left) table and the matching rows from the second (right) table.
Right OuterJoin - Returns all rows from the second (right) table and the matching rows from the first (left) table.
Full OuterJoin - Returns all rows from both tables.
AntiJoin - Returns only rows where JoinExpression in the left table doesn’t match anything in the right table.
This practice can help in reduce data redundancy, avoid conflicts while importing data, and build reliable, efficient, and easy to use reports that could facilitate the better business decision-making processes and that too efficiently.