Refactor to use association mapping for Employee-Department

Author: nakamura-to

dao-style-file/src/main/java/example/dao_style_file/dao/EmployeeDao.java

@@ -2,12 +2,15 @@
 
 import example.dao_style_file.domain.Age;
 import example.dao_style_file.domain.Salary;
+import example.dao_style_file.entity.Department;
 import example.dao_style_file.entity.Employee;
-import example.dao_style_file.entity.EmployeeDepartment;
 import java.time.LocalDateTime;
 import java.util.List;
+import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.stream.Stream;
+import org.seasar.doma.AggregateStrategy;
+import org.seasar.doma.AssociationLinker;
 import org.seasar.doma.Dao;
 import org.seasar.doma.Delete;
 import org.seasar.doma.Insert;
@@ -67,8 +70,8 @@ public interface EmployeeDao {
   @Select(strategy = SelectType.STREAM)
   <R> R selectByAge(int age, Function<Stream<Employee>, R> mapper);
 
-  @Select
-  List<EmployeeDepartment> selectAllEmployeeDepartment();
+  @Select(aggregateStrategy = EmployeeAggregateStrategy.class)
+  List<Employee> selectAllEmployeeDepartment();
 
   @Insert(sqlFile = true)
   int insert(Employee employee);
@@ -79,3 +82,13 @@ public interface EmployeeDao {
   @Delete(sqlFile = true)
   int delete(Employee employee);
 }
+
+@AggregateStrategy(root = Employee.class, tableAlias = "e")
+interface EmployeeAggregateStrategy {
+  @AssociationLinker(propertyPath = "department", tableAlias = "d")
+  BiFunction<Employee, Department, Employee> department =
+      (e, d) -> {
+        e.setDepartment(d);
+        return e;
+      };
+}

dao-style-file/src/main/java/example/dao_style_file/entity/Employee.java

@@ -4,6 +4,7 @@
 import example.dao_style_file.domain.Salary;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
+import org.seasar.doma.Association;
 import org.seasar.doma.Column;
 import org.seasar.doma.Entity;
 import org.seasar.doma.GeneratedValue;
@@ -12,7 +13,6 @@
 import org.seasar.doma.Metamodel;
 import org.seasar.doma.OriginalStates;
 import org.seasar.doma.SequenceGenerator;
-import org.seasar.doma.Transient;
 import org.seasar.doma.Version;
 
 @Entity(listener = EmployeeListener.class, metamodel = @Metamodel)
@@ -45,7 +45,7 @@ public class Employee {
 
   LocalDateTime updateTimestamp;
 
-  @Transient Department department;
+  @Association Department department;
 
   @OriginalStates Employee originalStates;
 

dao-style-file/src/main/java/example/dao_style_file/entity/EmployeeDepartment.java

@@ -1,6 +1,5 @@
 select
-    e.*,
-    d.name department_name
+    /*%expand */*
 from
     employee e
 left outer join

dao-style-file/src/main/resources/META-INF/example/dao_style_file/dao/EmployeeDao/selectAllEmployeeDepartment.sql

@@ -8,8 +8,8 @@
 import example.dao_style_file.dao.EmployeeDaoImpl;
 import example.dao_style_file.domain.Age;
 import example.dao_style_file.domain.Salary;
+import example.dao_style_file.entity.Department;
 import example.dao_style_file.entity.Employee;
-import example.dao_style_file.entity.EmployeeDepartment;
 import java.time.LocalDateTime;
 import java.util.Arrays;
 import java.util.List;
@@ -163,10 +163,12 @@ public void testCount() {
 
   @Test
   public void testSelectJoinedResult() {
-    List<EmployeeDepartment> list = dao.selectAllEmployeeDepartment();
+    List<Employee> list = dao.selectAllEmployeeDepartment();
     assertEquals(14, list.size());
-    for (EmployeeDepartment e : list) {
-      assertNotNull(e.getDepartmentName());
+    for (Employee e : list) {
+      Department department = e.getDepartment();
+      assertNotNull(department);
+      assertNotNull(department.getName());
     }
   }
 }

dao-style-file/src/test/java/example/dao_style_file/SelectTest.java

@@ -2,12 +2,15 @@
 
 import example.dao_style_text.domain.Age;
 import example.dao_style_text.domain.Salary;
+import example.dao_style_text.entity.Department;
 import example.dao_style_text.entity.Employee;
-import example.dao_style_text.entity.EmployeeDepartment;
 import java.sql.Timestamp;
 import java.util.List;
+import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.stream.Stream;
+import org.seasar.doma.AggregateStrategy;
+import org.seasar.doma.AssociationLinker;
 import org.seasar.doma.Dao;
 import org.seasar.doma.Delete;
 import org.seasar.doma.Insert;
@@ -235,8 +238,7 @@ public interface EmployeeDao {
   @Sql(
       """
       select
-        e.*,
-        d.name department_name
+        /*%expand */*
       from
         employee e
       left outer join
@@ -246,8 +248,8 @@ public interface EmployeeDao {
       order by
         e.id
       """)
-  @Select
-  List<EmployeeDepartment> selectAllEmployeeDepartment();
+  @Select(aggregateStrategy = EmployeeAggregateStrategy.class)
+  List<Employee> selectAllEmployeeDepartment();
 
   @Sql(
       """
@@ -308,3 +310,13 @@ insert into Employee (
   @Delete
   int delete(Employee employee);
 }
+
+@AggregateStrategy(root = Employee.class, tableAlias = "e")
+interface EmployeeAggregateStrategy {
+  @AssociationLinker(propertyPath = "department", tableAlias = "d")
+  BiFunction<Employee, Department, Employee> department =
+      (e, d) -> {
+        e.setDepartment(d);
+        return e;
+      };
+}

dao-style-text/src/main/java/example/dao_style_text/dao/EmployeeDao.java

@@ -4,6 +4,7 @@
 import example.dao_style_text.domain.Salary;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
+import org.seasar.doma.Association;
 import org.seasar.doma.Column;
 import org.seasar.doma.Entity;
 import org.seasar.doma.GeneratedValue;
@@ -12,7 +13,6 @@
 import org.seasar.doma.Metamodel;
 import org.seasar.doma.OriginalStates;
 import org.seasar.doma.SequenceGenerator;
-import org.seasar.doma.Transient;
 import org.seasar.doma.Version;
 
 @Entity(listener = EmployeeListener.class, metamodel = @Metamodel)
@@ -45,7 +45,7 @@ public class Employee {
 
   LocalDateTime updateTimestamp;
 
-  @Transient Department department;
+  @Association Department department;
 
   @OriginalStates Employee originalStates;
 

dao-style-text/src/main/java/example/dao_style_text/entity/Employee.java

@@ -8,6 +8,7 @@
 import example.dao_style_text.dao.EmployeeDaoImpl;
 import example.dao_style_text.domain.Age;
 import example.dao_style_text.domain.Salary;
+import example.dao_style_text.entity.Department;
 import example.dao_style_text.entity.Employee;
 import java.sql.Timestamp;
 import java.util.List;
@@ -164,7 +165,9 @@ public void testSelectJoinedResult() {
     var list = dao.selectAllEmployeeDepartment();
     assertEquals(14, list.size());
     for (var e : list) {
-      assertNotNull(e.getDepartmentName());
+      Department department = e.getDepartment();
+      assertNotNull(department);
+      assertNotNull(department.getName());
     }
   }
 }