added new unit test with SalesDAO - db test

src/test/java/net/codejava/JUnit5ExampleTest11.java

@@ -0,0 +1,30 @@
+package net.codejava;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import java.util.List;
+
+@SpringBootTest
+public class JUnit5ExampleTest11 {
+
+    @Autowired
+    // create private instance of SalesDAO
+    private SalesDAO salesDAO = new SalesDAO();;
+
+    @Test
+    void testInsert() {
+      Sale sale = new Sale("test item 123", 1, 1);
+      salesDAO.save(sale);
+      // list all the records
+      List<Sale> listSale = salesDAO.list();
+      // print a comment about the latest item on the list
+      System.out.println("Expected item on the list: test item 123");
+      System.out.println("Actual item on the list: " + listSale.get(listSale.size()-1).getItem());
+      // assert that the latest item on the list is "test item 123"
+      assertEquals("test item 123", listSale.get(listSale.size()-1).getItem());
+      // clean up the database
+      salesDAO.delete(listSale.get(listSale.size()-1).getId());
+      System.out.println("\n\nTest11-1 Successful!\n\n");
+    }
+}