diff --git a/src/main/java/com/noorq/casser/core/Casser.java b/src/main/java/com/noorq/casser/core/Casser.java
index 9ae5522..b12efc5 100644
--- a/src/main/java/com/noorq/casser/core/Casser.java
+++ b/src/main/java/com/noorq/casser/core/Casser.java
@@ -26,7 +26,8 @@ import com.noorq.casser.config.CasserSettings;
 import com.noorq.casser.config.DefaultCasserSettings;
 import com.noorq.casser.core.reflect.CasserPropertyNode;
 import com.noorq.casser.core.reflect.DslExportable;
-import com.noorq.casser.mapping.MappingRepositoryBuilder;
+import com.noorq.casser.mapping.CasserMappingEntity;
+import com.noorq.casser.support.CasserMappingException;
 
 
 
@@ -113,4 +114,41 @@ public final class Casser {
 		return settings.getMapperInstantiator().instantiate(iface, src, classLoader);
 	}
 
+	public static CasserMappingEntity entity(Class<?> iface) {
+		
+		Object dsl = dsl(iface);
+		
+		DslExportable e = (DslExportable) dsl;
+		
+		return e.getCasserMappingEntity();
+	}
+	
+	public static CasserMappingEntity resolve(Object ifaceOrDsl) {
+		
+		if (ifaceOrDsl == null) {
+			throw new CasserMappingException("ifaceOrDsl is null");
+		}
+		
+		if (ifaceOrDsl instanceof DslExportable) {
+			
+			DslExportable e = (DslExportable) ifaceOrDsl;
+			
+			return e.getCasserMappingEntity();
+		}
+		
+		if (ifaceOrDsl instanceof Class) {
+			
+			Class<?> iface = (Class<?>) ifaceOrDsl;
+
+			if (!iface.isInterface()) {
+				throw new CasserMappingException("class is not an interface " + iface);
+			}
+			
+			return entity(iface);
+
+		}
+		
+		throw new CasserMappingException("unknown dsl object or mapping interface " + ifaceOrDsl);
+	}
+	
 }
diff --git a/src/main/java/com/noorq/casser/core/CasserSession.java b/src/main/java/com/noorq/casser/core/CasserSession.java
index 1a2beeb..e742e8b 100644
--- a/src/main/java/com/noorq/casser/core/CasserSession.java
+++ b/src/main/java/com/noorq/casser/core/CasserSession.java
@@ -117,26 +117,19 @@ public class CasserSession extends AbstractSessionOperations implements Closeabl
 	}
 
 	public <E> SelectOperation<E> select(Class<E> entityClass) {
-		Objects.requireNonNull(entityClass, "entityClass is empty");
-		
-		Class<?> iface = MappingUtil.getMappingInterface(entityClass);
-		CasserMappingEntity entity = mappingRepository.getEntity(iface);		
+		Objects.requireNonNull(entityClass, "entityClass is empty");		
 		ColumnValueProvider valueProvider = getValueProvider();
-		
+		CasserMappingEntity entity = Casser.entity(entityClass);
 		return new SelectOperation<E>(this, entity, (r) -> {
 			Map<String, Object> map = new RowProviderMap(r, valueProvider, entity);
-			return (E) Casser.map(iface, map);
+			return (E) Casser.map(entityClass, map);
 			
 		});
 	}
 	
 	public <E> SelectOperation<E> select(Class<E> entityClass, Function<Row, E> rowMapper) {
 		Objects.requireNonNull(entityClass, "entityClass is empty");
-		
-		Class<?> iface = MappingUtil.getMappingInterface(entityClass);
-		CasserMappingEntity entity = mappingRepository.getEntity(iface);
-		
-		return new SelectOperation<E>(this, entity, rowMapper);
+		return new SelectOperation<E>(this, Casser.entity(entityClass), rowMapper);
 	}
 	
 	public <V1> SelectOperation<Tuple1<V1>> select(Getter<V1> getter1) {
@@ -251,12 +244,7 @@ public class CasserSession extends AbstractSessionOperations implements Closeabl
 	
 	public CountOperation count(Object dsl) {
 		Objects.requireNonNull(dsl, "dsl is empty");
-		
-		Class<?> iface = MappingUtil.getMappingInterface(dsl);
-		
-		CasserMappingEntity entity = mappingRepository.getEntity(iface);
-		
-		return new CountOperation(this, entity);
+		return new CountOperation(this, Casser.resolve(dsl));
 	}
 	
 	public <V> UpdateOperation update() {
@@ -280,8 +268,7 @@ public class CasserSession extends AbstractSessionOperations implements Closeabl
 		Objects.requireNonNull(pojo, "pojo is empty");
 		
 		Class<?> iface = MappingUtil.getMappingInterface(pojo);
-		
-		CasserMappingEntity entity = mappingRepository.getEntity(iface);
+		CasserMappingEntity entity = Casser.entity(iface);
 		
 		return new InsertOperation(this, entity, pojo, true);
 	}
@@ -294,8 +281,7 @@ public class CasserSession extends AbstractSessionOperations implements Closeabl
 		Objects.requireNonNull(pojo, "pojo is empty");
 		
 		Class<?> iface = MappingUtil.getMappingInterface(pojo);
-		
-		CasserMappingEntity entity = mappingRepository.getEntity(iface);
+		CasserMappingEntity entity = Casser.entity(iface);
 		
 		return new InsertOperation(this, entity, pojo, false);
 	}
@@ -306,12 +292,7 @@ public class CasserSession extends AbstractSessionOperations implements Closeabl
 	
 	public DeleteOperation delete(Object dsl) {
 		Objects.requireNonNull(dsl, "dsl is empty");
-		
-		Class<?> iface = MappingUtil.getMappingInterface(dsl);
-		
-		CasserMappingEntity entity = mappingRepository.getEntity(iface);
-		
-		return new DeleteOperation(this, entity);
+		return new DeleteOperation(this, Casser.resolve(dsl));
 	}
 	
 	public Session getSession() {
diff --git a/src/main/java/com/noorq/casser/mapping/MappingRepositoryBuilder.java b/src/main/java/com/noorq/casser/mapping/MappingRepositoryBuilder.java
index 8c206a2..46ce420 100644
--- a/src/main/java/com/noorq/casser/mapping/MappingRepositoryBuilder.java
+++ b/src/main/java/com/noorq/casser/mapping/MappingRepositoryBuilder.java
@@ -80,18 +80,15 @@ public final class MappingRepositoryBuilder {
 	
 	public CasserMappingEntity add(Object dsl, Optional<CasserEntityType> type) {
 
-		Class<?> iface = MappingUtil.getMappingInterface(dsl);
+		CasserMappingEntity casserEntity = Casser.resolve(dsl);
+		
+		Class<?> iface = casserEntity.getMappingInterface();
+		
 		CasserMappingEntity entity = entityMap.get(iface);
 		
 		if (entity == null) {
 
-			if (!(dsl instanceof DslExportable)) {
-				dsl = Casser.dsl(iface);
-			}
-			
-			DslExportable e = (DslExportable) dsl;
-				
-			entity = e.getCasserMappingEntity();
+			entity = casserEntity;
 			
 			if (type.isPresent() && entity.getType() != type.get()) {
 				throw new CasserMappingException("unexpected entity type " + entity.getType() + " for " + entity);
diff --git a/src/main/java/com/noorq/casser/mapping/MappingUtil.java b/src/main/java/com/noorq/casser/mapping/MappingUtil.java
index 094c800..fd8763e 100644
--- a/src/main/java/com/noorq/casser/mapping/MappingUtil.java
+++ b/src/main/java/com/noorq/casser/mapping/MappingUtil.java
@@ -168,19 +168,19 @@ public final class MappingUtil {
 				.apply(iface.getSimpleName());
 	}
 
-	public static Class<?> getMappingInterface(Object entity) {
+	public static Class<?> getMappingInterface(Object pojo) {
 
 		Class<?> iface = null;
 
-		if (entity instanceof Class) {
-			iface = (Class<?>) entity;
+		if (pojo instanceof Class) {
+			iface = (Class<?>) pojo;
 
 			if (!iface.isInterface()) {
 				throw new CasserMappingException("expected interface " + iface);
 			}
 
 		} else {
-			Class<?>[] ifaces = entity.getClass().getInterfaces();
+			Class<?>[] ifaces = pojo.getClass().getInterfaces();
 			
 			int len = ifaces.length;
 			for (int i = 0; i != len; ++i) {
@@ -192,7 +192,8 @@ public final class MappingUtil {
 				}
 				
 				if (iface.getDeclaredAnnotation(Table.class) != null ||
-						iface.getDeclaredAnnotation(UserDefinedType.class) != null) {
+						iface.getDeclaredAnnotation(UserDefinedType.class) != null ||
+						iface.getDeclaredAnnotation(Tuple.class) != null) {
 					
 					break;
 					
@@ -204,7 +205,7 @@ public final class MappingUtil {
 		}
 
 		if (iface == null) {
-			throw new CasserMappingException("dsl interface not found for " + entity);
+			throw new CasserMappingException("dsl interface not found for " + pojo);
 		}
 		
 		return iface;