Create OOP for department

src/main/java/com/napier/sem/App.java

@@ -90,6 +90,9 @@ public static void main(String[] args)
         ArrayList<Employee> emp1 = employeeSQL.getAllSalaries();
         employeeDisplay.printSalaries(emp1);
 
+        DepartmentSQL departmentSQL = new DepartmentSQL(a.con);
+
+
         // Disconnect from database
         a.disconnect();
     }

src/main/java/com/napier/sem/Department.java

@@ -0,0 +1,37 @@
+package com.napier.sem;
+
+public class Department {
+    public String dept_name;
+    public String dept_no;
+    public Employee manager;
+
+    public Department(String dept_name, String dept_no, Employee manager) {
+        this.dept_name = dept_name;
+        this.dept_no = dept_no;
+        this.manager = manager;
+    }
+
+    public String getDept_name() {
+        return dept_name;
+    }
+
+    public void setDept_name(String dept_name) {
+        this.dept_name = dept_name;
+    }
+
+    public String getDept_no() {
+        return dept_no;
+    }
+
+    public void setDept_no(String dept_no) {
+        this.dept_no = dept_no;
+    }
+
+    public Employee getManager() {
+        return manager;
+    }
+
+    public void setManager(Employee manager) {
+        this.manager = manager;
+    }
+}

src/main/java/com/napier/sem/DepartmentSQL.java

@@ -0,0 +1,44 @@
+package com.napier.sem;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+
+public class DepartmentSQL {
+
+    private Connection con;
+
+    public DepartmentSQL(Connection conn) {
+
+        this.con = conn;
+    }
+
+    public Department getDepartment(String dept_name) {
+
+        try {
+            // Prepare SQL statement to prevent SQL injection
+            String strSelect = "SELECT dept_no, dept_name FROM departments WHERE dept_name = ?";
+            PreparedStatement pstmt = con.prepareStatement(strSelect);
+            pstmt.setString(1, dept_name);
+            ResultSet rset = pstmt.executeQuery();
+
+
+            if (rset.next()) {
+                // Here, we fetch department number as a string (like "d005")
+                String dept_no = rset.getString("dept_no");
+                // Assume that fetching the manager is handled separately
+                Employee manager = null;  // Placeholder for manager if needed
+                String dep_name = rset.getString("dept_name");
+                return new Department(dep_name, dept_no, manager);
+            } else {
+                return null;
+            }
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+            System.out.println("Failed to get department details");
+            return null;
+        }
+    }
+}

src/main/java/com/napier/sem/EmployeeSQL.java

@@ -81,4 +81,37 @@ public ArrayList<Employee> getAllSalaries() {
             return null;
         }
     }
+
+    public ArrayList<Employee> getSalariesByDepartment(Department dept) {
+        ArrayList<Employee> employees = new ArrayList<>();
+        try{
+            String strSelect = "SELECT employees.emp_no, employees.first_name, employees.last_name, salaries.salary " +
+                    "FROM employees, salaries, dept_emp, departments " +
+                    "WHERE employees.emp_no = salaries.emp_no " +
+                    "AND employees.emp_no = dept_emp.emp_no " +
+                    "AND dept_emp.dept_no = departments.dept_no " +
+                    "AND salaries.to_date = '9999-01-01' " +
+                    "AND departments.dept_no = '" + dept.getDept_no() + "' " +  // Dept no is treated as string
+                    "ORDER BY employees.emp_no ASC";
+
+            Statement stmt = con.createStatement();
+            ResultSet rset = stmt.executeQuery(strSelect);
+
+            while (rset.next()) {
+                Employee emp = new Employee();
+                emp.emp_no = rset.getInt("emp_no");
+                emp.first_name = rset.getString("first_name");
+                emp.last_name = rset.getString("last_name");
+                emp.salary = rset.getInt("salary");
+                employees.add(emp);
+            }
+            rset.close();
+            stmt.close();
+            return employees;
+        } catch (Exception e) {
+            e.printStackTrace();
+            System.out.println("Failed to get salary details");
+            return null;
+        }
+    }
 }