Implementation of scenario six + renaming of badly named property in Department model class + improved english grammar in comments ;)

Author: bwajtr

dbscenarios.txt

@@ -3,9 +3,9 @@
 3. Save new single entity and return primary key
 4. Batch insert multiple entities of same type and return generated keys
 5. Update single existing entity - update all fields of entity at once
-6. Fetch entity and it's manytoone relation (Company for Employee)
-7. Fetch entity and it's onetomany relation (Employees for Company)
-8. Update entitie's onetomany relation - add two items, update two items and delete one item
+6. Fetch entity and it's many-to-one relation (Company for Department)
+7. Fetch entity and it's one-to-many relation (Departments for Company)
+8. Update entitie's one-to-many relation - add two items, update two items and delete one item
 9. Complex select - construct select where conditions based on some boolean conditions + throw in some outer joins
 10. Transactions handling
 11. Call stored procedure

src/main/java/com/clevergang/dbtests/Scenarios.java

@@ -5,6 +5,8 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import com.clevergang.dbtests.model.Company;
+import com.clevergang.dbtests.model.Department;
 import com.clevergang.dbtests.model.Employee;
 import com.clevergang.dbtests.model.Project;
 import com.clevergang.dbtests.repository.DataRepository;
@@ -92,8 +94,20 @@ public void scenarioFive() {
 
     }
 
+    /**
+     * Fetch many-to-one relation (Company for Department)
+     */
     public void scenarioSix() {
+        Department softwareDevelopmentDepartment = repository.findDepartment(3);
+
+        // Getting Company for Department (many-to-one relation) in JPA is quite easy. You typically have
+        // @ManyToOne relation defined in the Department entity class, so once you have instance of Department,
+        // you just call department.getCompany() and JPA does the magic for you (typically one or more lazy selects
+        // are executed). We don't have any such magical call here, but non-JPA approach is quite straightforward
+        // too: we have company_pid, so just ask DataRepository for the record:
+        Company company = repository.findCompany(softwareDevelopmentDepartment.getCompanyPid());
 
+        logger.info("Department {} is in the {} company", softwareDevelopmentDepartment.getName(), company.getName());
     }
 
     public void scenarioSeven() {

src/main/java/com/clevergang/dbtests/model/Department.java

@@ -5,7 +5,7 @@
  */
 public class Department {
     private Integer pid;
-    private Integer department_pid;
+    private Integer company_pid;
     private String name;
 
     public Integer getPid() {
@@ -24,12 +24,12 @@ public void setName(String name) {
         this.name = name;
     }
 
-    public Integer getDepartmentPid() {
-        return department_pid;
+    public Integer getCompanyPid() {
+        return company_pid;
     }
 
-    public void setDepartmentPid(Integer department_pid) {
-        this.department_pid = department_pid;
+    public void setCompanyPid(Integer company_pid) {
+        this.company_pid = company_pid;
     }
 
     @Override
@@ -43,7 +43,7 @@ public boolean equals(Object o) {
 
         if (pid != null ? !pid.equals(that.pid) : that.pid != null)
             return false;
-        if (department_pid != null ? !department_pid.equals(that.department_pid) : that.department_pid != null)
+        if (company_pid != null ? !company_pid.equals(that.company_pid) : that.company_pid != null)
             return false;
         return name != null ? name.equals(that.name) : that.name == null;
 
@@ -52,7 +52,7 @@ public boolean equals(Object o) {
     @Override
     public int hashCode() {
         int result = pid != null ? pid.hashCode() : 0;
-        result = 31 * result + (department_pid != null ? department_pid.hashCode() : 0);
+        result = 31 * result + (company_pid != null ? company_pid.hashCode() : 0);
         result = 31 * result + (name != null ? name.hashCode() : 0);
         return result;
     }
@@ -61,7 +61,7 @@ public int hashCode() {
     public String toString() {
         return "Department{" +
             "pid=" + pid +
-            ", department_pid=" + department_pid +
+            ", company_pid=" + company_pid +
             ", name='" + name + '\'' +
             '}';
     }

src/main/java/com/clevergang/dbtests/repository/DataRepository.java

@@ -3,6 +3,7 @@
 import java.util.List;
 
 import com.clevergang.dbtests.model.Company;
+import com.clevergang.dbtests.model.Department;
 import com.clevergang.dbtests.model.Employee;
 import com.clevergang.dbtests.model.Project;
 
@@ -13,6 +14,8 @@ public interface DataRepository {
 
     Company findCompany(Integer pid);
 
+    Department findDepartment(Integer pid);
+
     List<Employee> employeesWithSalaryGreaterThan(Integer minSalary);
 
     Integer insertProject(Project project);

src/main/java/com/clevergang/dbtests/repository/impl/jdbctemplate/JDBCDataRepositoryImpl.java

@@ -6,6 +6,7 @@
 import java.util.Map;
 
 import com.clevergang.dbtests.model.Company;
+import com.clevergang.dbtests.model.Department;
 import com.clevergang.dbtests.model.Employee;
 import com.clevergang.dbtests.model.Project;
 import com.clevergang.dbtests.repository.DataRepository;
@@ -48,6 +49,18 @@ public Company findCompany(Integer pid) {
         return company;
     }
 
+    @Override
+    public Department findDepartment(Integer pid) {
+        String query = "SELECT pid, company_pid, name" +
+            "           FROM department " +
+            "           WHERE pid = :pid";
+
+        Map<String, Object> params = new HashMap<>();
+        params.put("pid", pid);
+
+        return jdbcTemplate.queryForObject(query, params, new BeanPropertyRowMapper<>(Department.class));
+    }
+
     @Override
     public List<Employee> employeesWithSalaryGreaterThan(Integer minSalary) {
         logger.info("Looking for employeesWithSalaryGreaterThan using JDBCTemplate");

src/main/java/com/clevergang/dbtests/repository/impl/jooq/JooqDataRepositoryImpl.java

@@ -5,6 +5,7 @@
 import java.util.List;
 
 import com.clevergang.dbtests.model.Company;
+import com.clevergang.dbtests.model.Department;
 import com.clevergang.dbtests.model.Employee;
 import com.clevergang.dbtests.model.Project;
 import com.clevergang.dbtests.repository.DataRepository;
@@ -44,6 +45,14 @@ public Company findCompany(Integer pid) {
         return company;
     }
 
+    @Override
+    public Department findDepartment(Integer pid) {
+        return create.
+            selectFrom(DEPARTMENT)
+            .where(DEPARTMENT.PID.eq(pid))
+            .fetchOneInto(Department.class);
+    }
+
     @Override
     public List<Employee> employeesWithSalaryGreaterThan(Integer minSalary) {
         logger.info("Looking for employeesWithSalaryGreaterThan using JOOQ");
@@ -100,12 +109,13 @@ public List<Integer> insertAllProjects(List<Project> projects) {
     public void updateEmployee(Employee employeeToUpdate) {
         logger.info("Updating employee using JOOQ");
 
-        // If the DTO object passed into this method field names match field names in the EmployeeRecord,
-        // then it's easier to use Records when updating all fields of the entity at once:
-        EmployeeRecord record = create.newRecord(EMPLOYEE, employeeToUpdate);
+        // If field names of the DTO object passed into this method match field names in the jooq Record class,
+        // then it's easier to use jooq Records when updating all fields of the entity at once (Employee field match EmployeeRecord fields):
+        EmployeeRecord record = new EmployeeRecord();
+        record.from(employeeToUpdate);  // <-- reflection based mapping, but you can use JPA @Column annotations too!
         create.executeUpdate(record);
 
-        // If the DTO object fields does not match the employee record, then you'll have to use mapping:
+        // If the DTO object fields do not match the employee record, then you'll have to use manual mapping:
         create.update(EMPLOYEE)
             .set(EMPLOYEE.DEPARTMENT_PID, employeeToUpdate.getDepartmentPid())
             .set(EMPLOYEE.NAME, employeeToUpdate.getName())