This type of relationship involves multiple connections of records in the first table with records in the second table.
Example 1: Calculating Monthly Payments
Let’s assume you manage a Design Service Agency and calculate monthly payments to each designer according to the hours they worked. In this case, a Many-to-Many relation between the "Hours Worked" table and the "Monthly Payments" table can be helpful.
In most cases, a Many-to-Many relation comprises match conditions. For example, there is the "Designer" column in the "Hours Worked" table and the "Monthly Payments" table. This column comprises Designer Id value. As a result, a Designer=Designer match condition can be added to the relation.
After that, the "Total Hours" summary column can be added to the "Monthly Payments" table, where the total number of designers’ worked hours is calculated.
Example 2: Managing Customer Claims
Let’s say your Health Insurance Claims database includes two tables: "Customers" and "Claims," which keep customers’ profiles and registered claims, respectively. Moreover, customers submit claims through a web-to-record form embedded into your website. Therefore, in your database, you need to relate submitted claims to a corresponding customer profile automatically using an email kept in the customer profile and an email specified in the submitted claim.
Firstly, you need to build a Many-to-Many relation between the "Customers" table and the "Claims" table.
As a result, claims are related to a customer by the email value. Also, you can see such claims in the details view displayed below a Customer record form.