Entity Framework Plus Query DbSetFilter
Definition
The Query DbSetFilter is the old filter API for Entity Framework 6 (EF6) before the code switched to use Interceptor instead.
The feature revamp was done in 2016 to support include and LazyLoading but, also have some limitation such as performance and instance filter that the old code didn't have.
Limitations
- DO NOT Support include
- DO NOT Support lazy loading
API Rename
To make both features live together, method in Query DbSetFilter has been renamed to add prefix with DbSet before Filter.
| Query Filter | Query DbSetFilter |
|---|---|
| AsNoFilter | AsNoDbSetFilter |
| Filter | DbSetFilter |
| QueryFilterManager | QueryDbSetFilterManager |
EF+ Query Filter Global
Global filter can be used by any context.
Global filter is normally preferred in most scenarios over instance filter since the filter code is centralized in one method over being spread in multiple methods.
// using Z.EntityFramework.Plus; // Don't forget to include this. QueryDbSetFilterManager.Filter<Customer>(q => q.Where(x => x.IsActive)); var ctx = new EntitiesContext(); // TIP: You can also add this line in EntitiesContext constructor instead QueryDbSetFilterManager.InitilizeGlobalFilter(ctx); // SELECT * FROM Customer WHERE IsActive = true var list = ctx.Customers.ToList();
Use entities context constructor to initialize global filter by default.
EF+ Query Filter By Instance
Instance filter applies filters to the current context only. The filtering logic is added once the context is created.
// using Z.EntityFramework.Plus; // Don't forget to include this. var ctx = new EntitiesContext(); ctx.DbSetFilter<Customer>(q => q.Where(x => x.IsActive)); // SELECT * FROM Customer WHERE IsActive = true var list = ctx.Customers.ToList();
Use entities context constructor to make some filter "global" to all context.
EF+ Query Filter By Query
Query filter applies filters to specific queries only. The filtering logic is added globally or by instance but in a disabled state and then it is enabled by these specific queries.
// using Z.EntityFramework.Plus; // Don't forget to include this. var ctx = new EntitiesContext(); // CREATE a disabled filter ctx.DbSetFilter<Customer>(MyEnum.EnumValue, q => q.Where(x => x.IsActive), false); // SELECT * FROM Customer var list = ctx.Customers.DbSetFilter(MyEnum.EnumValue).ToList();
EF+ Query Filter By Inheritance/Interface
Filter can be enabled and disabled by class inheritance and interface.
// using Z.EntityFramework.Plus; // Don't forget to include this. var ctx = new EntitiesContext(); // CREATE filter by inheritance ctx.DbSetFilter<BaseDog>(q => q.Where(x => !x.IsDangerous)); // CREATE filter by interface ctx.DbSetFilter<IAnimal>(q => q.Where(x => x.IsDomestic)); // SELECT * FROM Cat WHERE IsDomestic = 1 var cats = ctx.Cats.ToList(); // SELECT * FROM Dog WHERE IsDomestic = 1 AND IsDangerous = 0 var dogs = ctx.Dogs.ToList();
EF+ Query Filter Enable/Disable
Filters are very flexible, you can enable and disable them at any time and only for a specific inheritance or interface if desired.
// using Z.EntityFramework.Plus; // Don't forget to include this. var ctx = new EntitiesContext(); // CREATE filter by interface ctx.DbSetFilter<IAnimal>(MyEnum.EnumValue, q => q.Where(x => x.IsDomestic)) // DISABLE filter ctx.DbSetFilter(MyEnum.EnumValue).Disable(); // SELECT * FROM Dog var dogs = ctx.Dogs.ToList(); // ENABLE filter ctx.DbSetFilter(MyEnum.EnumValue).Enable(); // SELECT * FROM Dog WHERE IsDomestic = true var dogs = ctx.Dogs.ToList();
EF+ Query Filter AsNoFilter
You can bypass all filters by using AsNoFilter method in a query if a special scenario doesn't require filtering.
// using Z.EntityFramework.Plus; // Don't forget to include this. var ctx = new EntitiesContext(); this.DbSetFilter<Customer>(q => q.Where(x => x.IsActive)); // SELECT * FROM Customer WHERE IsActive = true var list = ctx.Customers.ToList(); // SELECT * FROM Customer var list = ctx.Customers.AsNoDbSetFilter().ToList();