diff --git a/build.gradle.kts b/build.gradle.kts
index bc11d04..51b59ac 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -9,7 +9,7 @@ plugins {
 }
 
 group = "com.aitrainer"
-version = "0.0.2"
+version = "0.0.3"
 java.sourceCompatibility = JavaVersion.VERSION_1_8
 
 repositories {
diff --git a/src/main/kotlin/com/aitrainer/api/model/Exercises.kt b/src/main/kotlin/com/aitrainer/api/model/Exercises.kt
index 6f706c9..bb2736c 100644
--- a/src/main/kotlin/com/aitrainer/api/model/Exercises.kt
+++ b/src/main/kotlin/com/aitrainer/api/model/Exercises.kt
@@ -14,7 +14,7 @@ data class Exercises (
         @get: NonNull var customerId: Long = 0,
         @get: NonNull var datetimeExercise: Date? = null,
         @get: NonNull var quantity: Int = 0,
-        @get: Null var restTime: Integer, // in seconds
+        @get: Null var restTime: Int?, // in seconds
 
         @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
     val exerciseId: Long = 0
diff --git a/src/main/kotlin/com/aitrainer/api/service/ExerciseService.kt b/src/main/kotlin/com/aitrainer/api/service/ExerciseService.kt
new file mode 100644
index 0000000..0b951ef
--- /dev/null
+++ b/src/main/kotlin/com/aitrainer/api/service/ExerciseService.kt
@@ -0,0 +1,10 @@
+package com.aitrainer.api.service
+
+import com.aitrainer.api.model.Exercises
+import org.springframework.data.jpa.repository.Query
+import org.springframework.data.repository.query.Param
+
+interface ExerciseService {
+    @Query("FROM Exercises WHERE customer_id = :customerId")
+    fun findAllByCustomerId( @Param("customerId") customerId: Long): List<Exercises>
+}
\ No newline at end of file
diff --git a/src/test/kotlin/com/aitrainer/api/test/ExerciseTest.kt b/src/test/kotlin/com/aitrainer/api/test/ExerciseTest.kt
new file mode 100644
index 0000000..497423f
--- /dev/null
+++ b/src/test/kotlin/com/aitrainer/api/test/ExerciseTest.kt
@@ -0,0 +1,28 @@
+package com.aitrainer.api.test
+
+import com.aitrainer.api.model.Exercises
+import com.aitrainer.api.repository.ExercisesRepository
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.context.SpringBootTest
+import kotlin.test.assertEquals
+
+@SpringBootTest
+class ExerciseTest {
+
+    @Autowired
+    private lateinit var exerciseRepository: ExercisesRepository
+
+    @Test
+    fun testGet() {
+        var id: Long = 1
+
+        val exercises: List<Exercises> = exerciseRepository.getAllByCustomerId( id )
+        assertEquals( exercises[0].quantity, 12)
+
+        id = 100000
+        val exercises2: List<Exercises> = exerciseRepository.getAllByCustomerId( id )
+
+        assertEquals( exercises2.size, 0)
+    }
+}
\ No newline at end of file