Free Joins (Query Non-Associated Data & Calculate Aggregations)

• Nov 01, 2024
• 2 minutes to read

Free Joins allows you to build criteria based on persistent objects that are not directly related (don’t have explicitly defined associations). You can:

• join any persistent objects on a condition;
• calculate aggregate functions against matching objects using their properties;
• return aggregate values as the result of joining.

To accomplish this, use JoinOperands in your criteria.

Note

You can use Free Joins in XPO and EF Core-based XAF applications.

Options for creating the JoinOperand include:

• The CriteriaOperator.Parse method.

• The JoinOperand constructors.

• The Join operation in LINQ to XPO.

See Also

Select Data from Multiple Tables

Build Criteria - Cheat Sheet