Contents

• Query Expressions
  • Supported arithmetic
  • Some examples
  • Built-in Expressions
    • F() expressions
      • Avoiding race conditions using F()
      • F() assignments persist after Model.save()
      • Using F() in filters
      • Using F() with annotations
      • Using F() to sort null values
    • Func() expressions
    • Aggregate() expressions
    • Creating your own Aggregate Functions
    • Value() expressions
    • ExpressionWrapper() expressions
    • Conditional expressions
    • Subquery() expressions
      • Referencing columns from the outer queryset
      • Limiting a subquery to a single column
      • Limiting the subquery to a single row
      • Exists() subqueries
      • Filtering on a Subquery expression
      • Using aggregates within a Subquery expression
    • Raw SQL expressions
    • Window functions
      • Frames
  • Technical Information
    • Expression API
    • Writing your own Query Expressions
      • Avoiding SQL injection
    • Adding support in third-party database backends