feat: lesson_25/lindaquinoa/intro to databases

lesson_25/db/db_app/src/main/java/com/codedifferently/lesson25/factory/LibraryDbDataLoader.java

@@ -2,6 +2,7 @@
 
 import com.codedifferently.lesson25.models.LibraryDataModel;
 import com.codedifferently.lesson25.repository.LibraryGuestRepository;
+import com.codedifferently.lesson25.repository.LibraryUserRepository;
 import com.codedifferently.lesson25.repository.MediaItemRepository;
 import java.io.IOException;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -13,13 +14,15 @@ public final class LibraryDbDataLoader implements LibraryDataLoader {
 
   @Autowired private MediaItemRepository mediaItemsRepository;
   @Autowired private LibraryGuestRepository libraryGuestRepository;
+  @Autowired private LibraryUserRepository libraryUserRepository;
 
   @Override
   public LibraryDataModel loadData() throws IOException {
     var model = new LibraryDataModel();
 
     model.mediaItems = mediaItemsRepository.findAll();
     model.guests = libraryGuestRepository.findAll();
+    model.users = libraryUserRepository.findAll();
 
     return model;
   }

lesson_25/db/db_app/src/main/java/com/codedifferently/lesson25/models/LibraryDataModel.java

@@ -17,6 +17,7 @@ public class LibraryDataModel {
 
   public List<MediaItemModel> mediaItems;
   public List<LibraryGuestModel> guests;
+  public List<LibraryUserModel> users;
 
   public List<MediaItem> getMediaItems() {
     List<MediaItem> results = new ArrayList<>();
@@ -52,6 +53,10 @@ public List<LibraryGuest> getGuests() {
     return results;
   }
 
+  public List<LibraryUserModel> getUsers() {
+    return this.users;
+  }
+
   public Map<String, List<CheckoutModel>> getCheckoutsByEmail() {
     Map<String, List<CheckoutModel>> results = new HashMap<>();
     for (LibraryGuestModel guest : this.guests) {

lesson_25/db/db_app/src/main/java/com/codedifferently/lesson25/models/LibraryUserModel.java

@@ -0,0 +1,22 @@
+package com.codedifferently.lesson25.models;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+
+@Entity
+@Table(name = "library_users")
+public class LibraryUserModel {
+
+  @Id public String id;
+  public String email;
+
+  @Column(name = "first_name")
+  public String firstName;
+
+  @Column(name = "last_name")
+  public String lastName;
+
+  public String password;
+}

lesson_25/db/db_app/src/main/java/com/codedifferently/lesson25/repository/LibraryUserRepository.java

@@ -0,0 +1,11 @@
+package com.codedifferently.lesson25.repository;
+
+import com.codedifferently.lesson25.models.LibraryUserModel;
+import java.util.List;
+import org.springframework.data.repository.CrudRepository;
+
+public interface LibraryUserRepository extends CrudRepository<LibraryUserModel, String> {
+
+  @Override
+  List<LibraryUserModel> findAll();
+}

lesson_25/db/db_app/src/main/resources/queries/lindaquinoa.sql

@@ -0,0 +1,17 @@
+-- Query 1: Count of media items by type
+SELECT type, COUNT(*) as item_count
+FROM media_items
+GROUP BY type
+ORDER BY type;
+
+-- Query 2: Sum of total pages checked out by guests
+SELECT SUM(mi.pages) as total_pages_checked_out
+FROM checked_out_items coi
+JOIN media_items mi ON coi.item_id = mi.id
+WHERE mi.pages IS NOT NULL;
+
+-- Query 3: All 5 guests with corresponding checked_out_items records
+SELECT g.type, g.name, g.email, coi.item_id, coi.due_date
+FROM guests g
+LEFT JOIN checked_out_items coi ON g.email = coi.email
+ORDER BY g.name, coi.due_date;