Create ef6-query-db-set-filter-by-inheritance-interface.md

Author: waqasm78

docs2/pages/ef-docs/documentations/query-db-set-filter/options/ef6-query-db-set-filter-by-inheritance-interface.md

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+---
+Permalink: ef6-query-db-set-filter-by-inheritance-interface
+---
+
+# EF+ Query Filter By Inheritance/Interface
+
+Filter can be enabled and disabled by class inheritance and interface.
+
+{% include template-example.html %} 
+```csharp
+
+// 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();
+
+```
+[Try it](https://dotnetfiddle.net/flFnBf)