Added CRUD to productSuppliers

-add CRUD to productSupplier and changed sqlDatabase so cost is in productSuppliers table

src/main/java/org/example/petshopdesktop/DTOs/ProductSupplierDTO.java

@@ -0,0 +1,83 @@
+package org.example.petshopdesktop.DTOs;
+
+import javafx.beans.property.SimpleDoubleProperty;
+import javafx.beans.property.SimpleIntegerProperty;
+import javafx.beans.property.SimpleStringProperty;
+
+public class ProductSupplierDTO {
+    private SimpleIntegerProperty supId;
+    private SimpleIntegerProperty prodId;
+    private SimpleStringProperty supCompany;
+    private SimpleStringProperty prodName;
+    private SimpleDoubleProperty cost;
+
+    //constructor
+    public ProductSupplierDTO(int supId, int prodId, String supCompany, String prodName, double cost) {
+        this.supId = new SimpleIntegerProperty(supId);
+        this.prodId = new SimpleIntegerProperty(prodId);
+        this.supCompany = new SimpleStringProperty(supCompany);
+        this.prodName = new SimpleStringProperty(prodName);
+        this.cost = new SimpleDoubleProperty(cost);
+    }
+
+    //getter and setters
+    public int getSupId() {
+        return supId.get();
+    }
+
+    public SimpleIntegerProperty supIdProperty() {
+        return supId;
+    }
+
+    public void setSupId(int supId) {
+        this.supId.set(supId);
+    }
+
+    public int getProdId() {
+        return prodId.get();
+    }
+
+    public SimpleIntegerProperty prodIdProperty() {
+        return prodId;
+    }
+
+    public void setProdId(int prodId) {
+        this.prodId.set(prodId);
+    }
+
+    public String getSupCompany() {
+        return supCompany.get();
+    }
+
+    public SimpleStringProperty supCompanyProperty() {
+        return supCompany;
+    }
+
+    public void setSupCompany(String supCompany) {
+        this.supCompany.set(supCompany);
+    }
+
+    public String getProdName() {
+        return prodName.get();
+    }
+
+    public SimpleStringProperty prodNameProperty() {
+        return prodName;
+    }
+
+    public void setProdName(String prodName) {
+        this.prodName.set(prodName);
+    }
+
+    public double getCost() {
+        return cost.get();
+    }
+
+    public SimpleDoubleProperty costProperty() {
+        return cost;
+    }
+
+    public void setCost(double cost) {
+        this.cost.set(cost);
+    }
+}

src/main/java/org/example/petshopdesktop/controllers/ProductController.java

@@ -105,7 +105,7 @@ public class ProductController {
         try{
             data = ProductDB.getProductDTO();
         } catch (SQLException e) {
-            System.out.println(e.getMessage());
+            System.out.println("Error while fetching table data: " + e.getMessage());
         }
 
         //put data in the table
@@ -114,7 +114,7 @@ public class ProductController {
 
     /**
      * open a new dialog for adding a product
-     * @param event
+     * @param event click event for button
      */
     @FXML
     void btnAddClicked(ActionEvent event) {
@@ -211,7 +211,7 @@ public class ProductController {
                 tvProducts.setItems(data);
             }
         } catch (Exception e) {
-            throw new RuntimeException(e);
+            System.out.println("Error while fetching table data: " + e.getMessage());
         }
     }
 

src/main/java/org/example/petshopdesktop/controllers/ProductSupplierController.java

@@ -1,11 +1,27 @@
 package org.example.petshopdesktop.controllers;
 
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
 import javafx.event.ActionEvent;
 import javafx.fxml.FXML;
-import javafx.scene.control.Button;
-import javafx.scene.control.TableColumn;
-import javafx.scene.control.TableView;
-import javafx.scene.control.TextField;
+import javafx.fxml.FXMLLoader;
+import javafx.scene.Scene;
+import javafx.scene.control.*;
+import javafx.scene.control.cell.PropertyValueFactory;
+import javafx.stage.Modality;
+import javafx.stage.Stage;
+import org.example.petshopdesktop.DTOs.ProductDTO;
+import org.example.petshopdesktop.DTOs.ProductSupplierDTO;
+import org.example.petshopdesktop.controllers.dialogcontrollers.ProductDialogController;
+import org.example.petshopdesktop.controllers.dialogcontrollers.ProductSupplierDialogController;
+import org.example.petshopdesktop.database.ProductDB;
+import org.example.petshopdesktop.database.ProductSupplierDB;
+import org.example.petshopdesktop.models.ProductSupplier;
+
+import java.io.IOException;
+import java.sql.SQLException;
+import java.sql.SQLIntegrityConstraintViolationException;
+import java.util.Optional;
 
 public class ProductSupplierController {
 
@@ -19,39 +35,222 @@ public class ProductSupplierController {
     private Button btnEdit;
 
     @FXML
-    private TableColumn<?, ?> colCost;
+    private TableColumn<ProductSupplierDTO, Double> colCost;
 
     @FXML
-    private TableColumn<?, ?> colProductId;
+    private TableColumn<ProductSupplierDTO, Integer> colProductId;
 
     @FXML
-    private TableColumn<?, ?> colProductName;
+    private TableColumn<ProductSupplierDTO, String> colProductName;
 
     @FXML
-    private TableColumn<?, ?> colSupplierId;
+    private TableColumn<ProductSupplierDTO, Integer> colSupplierId;
 
     @FXML
-    private TableColumn<?, ?> colSupplierName;
+    private TableColumn<ProductSupplierDTO, String> colSupplierName;
 
     @FXML
-    private TableView<?> tvProductSuppliers;
+    private TableView<ProductSupplierDTO> tvProductSuppliers;
 
     @FXML
     private TextField txtSearch;
 
+    //data declaration
+    private ObservableList<ProductSupplierDTO> data = FXCollections.observableArrayList();
+    private String mode = null;
+
+    /**
+     * Set up the table view for table and display it when starting up
+     */
     @FXML
-    void btnAddClicked(ActionEvent event) {
+    public void initialize() {
+        //Disable buttons until a row is selected
+        btnEdit.setDisable(true);
+        btnDelete.setDisable(true);
+        //set up table columns
+        colProductId.setCellValueFactory(new PropertyValueFactory<ProductSupplierDTO,Integer>("prodId"));
+        colProductName.setCellValueFactory(new PropertyValueFactory<ProductSupplierDTO,String>("prodName"));
+        colSupplierId.setCellValueFactory(new PropertyValueFactory<ProductSupplierDTO,Integer>("supId"));
+        colSupplierName.setCellValueFactory(new PropertyValueFactory<ProductSupplierDTO,String>("supCompany"));
+        colCost.setCellValueFactory(new PropertyValueFactory<ProductSupplierDTO,Double>("cost"));
+
+        displayProductSupplier();
+
+        //EventListener to Enable buttons when a row is selected
+        tvProductSuppliers.getSelectionModel().selectedItemProperty().addListener(
+                (observable, oldValue, newValue) -> {
+                    btnEdit.setDisable(false);
+                    btnDelete.setDisable(false);
+                }
+        );
+
+        //EventListener to search when text is changed on searchbar
+        txtSearch.textProperty().addListener((observable, oldValue, newValue) -> {
+            displayFilteredProductSupplier(newValue);
+        });
 
     }
 
+    /**
+     * Display the ProductSupplierDTO to table view
+     */
+    private void displayProductSupplier() {
+        //Erase old content
+        data.clear();
+
+        //get ProductSupplier from database
+        try{
+            data = ProductSupplierDB.getProductSupplierDTO();
+        } catch (SQLException e) {
+            System.out.println("Error while fetching table data: " + e.getMessage());
+        }
+
+        //put data in the table
+        tvProductSuppliers.setItems(data);
+    }
+
+    /**
+     * Filter the table given the string from the searchbar
+     * @param filter word to filter table
+     */
+    private void displayFilteredProductSupplier(String filter){
+        data.clear();
+        try{
+            if (txtSearch.getText() == null || txtSearch.getText().isEmpty()){
+                displayProductSupplier(); //If search bar is empty just display everything
+            }
+            else{
+                //Filter the using the keyword
+                data = ProductSupplierDB.getFilteredProductSupplierDTO(filter);
+                tvProductSuppliers.setItems(data);
+            }
+        } catch (Exception e) {
+            System.out.println("Error while fetching table data: " + e.getMessage());
+        }
+    }
+
+    /**
+     * open a new dialog for adding a productSupplier
+     * @param event click event for button
+     */
+    @FXML
+    void btnAddClicked(ActionEvent event) {
+        mode = "Add";
+        openDialog(null,mode);
+    }
+
+    /**
+     * Delete a selected productSupplier when delete is clicked
+     * @param event click event for button
+     */
     @FXML
     void btnDeleteClicked(ActionEvent event) {
+        int numRows = 0;
+        //set selected item
+        ProductSupplierDTO selectedProductSupplier = tvProductSuppliers.getSelectionModel().getSelectedItem();
 
+        //ask user to confirm
+        Alert question = new Alert(Alert.AlertType.CONFIRMATION);
+        question.setHeaderText("Please confirm delete");
+        question.setContentText("Are you sure you want to delete this product-supplier?");
+        Optional<ButtonType> result = question.showAndWait(); //show alert and wait for response
+
+        //if confirmed,start deletion
+        if (result.isPresent() && result.get() == ButtonType.OK) {
+            int supId = selectedProductSupplier.getSupId();
+            int prodId = selectedProductSupplier.getProdId();
+
+            //try deleting
+            try{
+                numRows = ProductSupplierDB.deleteProductSupplier(supId, prodId);
+            }
+            catch (SQLIntegrityConstraintViolationException e){
+                Alert alert = new Alert(Alert.AlertType.ERROR);
+                alert.setHeaderText("Database Operation Error");
+                alert.setContentText("Delete failed\n" +
+                        "the selected product-supplier is being referred in another table");
+                alert.showAndWait();
+                return;
+            }
+            catch (SQLException e) {
+                throw new RuntimeException(e);
+            }
+
+            //prompt user of any errors
+            if (numRows == 0){
+                Alert alert = new Alert(Alert.AlertType.ERROR);
+                alert.setHeaderText("Database Operation Error");
+                alert.setContentText("Delete failed");
+                alert.showAndWait();
+            }
+            else{
+                //prompt user of delete conformation
+                Alert alert = new Alert(Alert.AlertType.CONFIRMATION);
+                alert.setHeaderText("Database Operation Confirmed");
+                alert.setContentText("Delete successful");
+                alert.showAndWait();
+                //refresh display and reset inputs
+                displayProductSupplier();
+                btnDelete.setDisable(true);
+                btnEdit.setDisable(true);
+                txtSearch.setText("");
+            }
+        }
     }
 
     @FXML
     void btnEditClicked(ActionEvent event) {
+        //set selected item
+        ProductSupplierDTO selectedProductSupplier = tvProductSuppliers.getSelectionModel().getSelectedItem();
 
+        if (selectedProductSupplier != null) {
+            mode = "Edit";
+            openDialog(selectedProductSupplier,mode);
+        }
+    }
+
+    /**
+     * Function to open the new Dialog for edit or adding
+     * depending on the mode given
+     * @param productSupplier the productSupplier entity for editing, null if adding
+     * @param mode the mode the dialog should be in
+     */
+    private void openDialog(ProductSupplierDTO productSupplier, String mode){
+        //Get new view
+        FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("/org/example/petshopdesktop/dialogviews/product-supplier-dialog-view.fxml"));
+        Scene scene = null;
+        try{
+            scene = new Scene(fxmlLoader.load());
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        ProductSupplierDialogController dialogController = fxmlLoader.getController(); //controller associated with this view
+        dialogController.setMode(mode);
+        if (productSupplier != null) {
+            dialogController.setSelectedIds(productSupplier.getSupId(), productSupplier.getProdId());
+        }
+
+        //Open the dialog depending on the mode
+        if(mode.equals("Edit")){
+            //Make it display suppliers details in dialog
+            dialogController.displayProductSupplierDetails(productSupplier);
+        }
+        Stage dialogStage = new Stage();
+        dialogStage.initModality(Modality.APPLICATION_MODAL); //make it modal
+        if(mode.equals("Add")){
+            dialogStage.setTitle("Add Product-Supplier");
+        }
+        else {
+            dialogStage.setTitle("Edit Product-Supplier");
+        }
+        dialogStage.setScene(scene);
+        dialogStage.showAndWait();
+
+        //When dialog closes update table view and disable edit and delete buttons, and reset search bar
+        displayProductSupplier();
+        btnDelete.setDisable(true);
+        btnEdit.setDisable(true);
+        txtSearch.setText("");
     }
 
 }

src/main/java/org/example/petshopdesktop/controllers/SupplierController.java

@@ -99,7 +99,7 @@ public class SupplierController {
         try{
             data = SupplierDB.getSuppliers();
         } catch (SQLException e) {
-            throw new RuntimeException(e);
+            System.out.println("Error while fetching table data: " + e.getMessage());
         }
 
         tvSuppliers.setItems(data);
@@ -121,7 +121,7 @@ public class SupplierController {
                 tvSuppliers.setItems(data);
             }
         } catch (Exception e) {
-            throw new RuntimeException(e);
+            System.out.println("Error while fetching table data: " + e.getMessage());
         }
     }
 

src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ProductDialogController.java

@@ -79,6 +79,11 @@ public class ProductDialogController {
 
     }
 
+    /**
+     * Validates the inputs, then add or update the database depending
+     * on the mode
+     * @param mouseEvent click event for save button
+     */
     private void buttonSaveClicked(MouseEvent mouseEvent) {
         int numRow = 0; //how many rows affected
         String errorMsg = ""; //error message for validation
@@ -164,7 +169,7 @@ public class ProductDialogController {
 
     /**
      * Display the product data in text fields and combobox
-     * @param product the supplier entity containing data to display
+     * @param product the product entity containing data to display
      */
     public void displayProductDetails(ProductDTO product){
         if (product!=null){
@@ -176,7 +181,7 @@ public class ProductDialogController {
             //get the right combobox selection
             for (Category category : cbProdCategory.getItems()) {
                 if(category.getCategoryId() == product.getCategoryId()){
-                    cbProdCategory.setValue(category);
+                    cbProdCategory.getSelectionModel().select(category);
                 }
             }
 

src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ProductSupplierDialogController.java

@@ -0,0 +1,245 @@
+package org.example.petshopdesktop.controllers.dialogcontrollers;
+
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.event.EventHandler;
+import javafx.fxml.FXML;
+import javafx.scene.Node;
+import javafx.scene.control.*;
+import javafx.scene.input.MouseEvent;
+import javafx.stage.Stage;
+import org.example.petshopdesktop.DTOs.ProductSupplierDTO;
+import org.example.petshopdesktop.Validator;
+import org.example.petshopdesktop.database.ProductDB;
+import org.example.petshopdesktop.database.ProductSupplierDB;
+import org.example.petshopdesktop.database.SupplierDB;
+import org.example.petshopdesktop.models.Product;
+import org.example.petshopdesktop.models.ProductSupplier;
+import org.example.petshopdesktop.models.Supplier;
+
+import java.sql.SQLException;
+import java.sql.SQLIntegrityConstraintViolationException;
+
+public class ProductSupplierDialogController {
+
+    @FXML
+    private Button btnCancel;
+
+    @FXML
+    private Button btnSave;
+
+    @FXML
+    private ComboBox<Product> cbProduct;
+
+    @FXML
+    private ComboBox<Supplier> cbSupplier;
+
+    @FXML
+    private Label lblMode;
+
+    @FXML
+    private Label lblProductSupplierId;
+
+    @FXML
+    private TextField txtCost;
+
+    private String mode = null;
+    private int selectedSupId = -1;
+    private int selectedProdId = -1;
+
+    /**
+     * add event listeners to buttons and set up combobox
+     */
+    @FXML
+    void initialize() {        //Set up mouse handlers for buttons
+        btnSave.setOnMouseClicked(new EventHandler<MouseEvent>() {
+            @Override
+            public void handle(MouseEvent mouseEvent) {
+                buttonSaveClicked(mouseEvent);
+            }
+        });
+
+        btnCancel.setOnMouseClicked(new EventHandler<MouseEvent>() {
+            @Override
+            public void handle(MouseEvent mouseEvent) {
+                closeStage(mouseEvent);
+            }
+        });
+
+        //Set up combobox for selecting product and supplier
+        try{
+            ObservableList<Supplier> suppliers = FXCollections.observableArrayList(); //empty list
+            ObservableList<Product> products = FXCollections.observableArrayList(); //empty list
+
+            //get suppliers and products from DB
+            suppliers = SupplierDB.getSuppliers();
+            products = ProductDB.getProducts();
+
+            //Populate combobox
+            cbSupplier.setItems(suppliers);
+            cbProduct.setItems(products);
+        }
+        catch(SQLException e){
+            throw new RuntimeException(e);
+        }
+
+    }
+
+    /**
+     * Validates the inputs, then add or update the database depending
+     * on the mode
+     * @param mouseEvent click event for save button
+     */
+    private void buttonSaveClicked(MouseEvent mouseEvent) {
+        int numRows = 0;
+        String errorMsg = ""; //error message for validation
+
+        //Check Validation (input required)
+        errorMsg += Validator.isPresent(txtCost.getText(), "Cost");
+        if (cbProduct.getSelectionModel().getSelectedItem() == null) {
+            errorMsg += "Product is required \n";
+        }
+        if (cbSupplier.getSelectionModel().getSelectedItem() == null) {
+            errorMsg += "Supplier is required \n";
+        }
+
+        //Check validation (length size)
+        errorMsg += Validator.isLessThanVarChars(txtCost.getText(), "Cost", 12);
+
+        //Check validation (format)
+        errorMsg += Validator.isNonNegativeDouble(txtCost.getText(), "Cost");
+
+        if(errorMsg.isEmpty()){ //no validation errors
+            ProductSupplier productSupplier = collectProductSupplier(); //get productSupplier info
+            if (mode.equals("Add")) { //add mode
+                try{
+                    numRows = ProductSupplierDB.insertProductSupplier(productSupplier);
+                }
+                catch(SQLIntegrityConstraintViolationException e){
+                    Alert alert = new Alert(Alert.AlertType.ERROR);
+                    alert.setHeaderText("Database Operation Error");
+                    alert.setContentText("Add failed \n" +
+                            "the product-supplier link is already in the database");
+                    alert.showAndWait();
+                    numRows = -1; //Update numRow so alert only shows once
+                    closeStage(mouseEvent);
+                }
+                catch(SQLException e){
+                    throw new RuntimeException(e);
+                }
+            }
+            else { //edit
+                try{
+                    numRows = ProductSupplierDB.updateProductSupplier(selectedSupId, selectedProdId, productSupplier);
+                }
+                catch(SQLIntegrityConstraintViolationException e){
+                    Alert alert = new Alert(Alert.AlertType.ERROR);
+                    alert.setHeaderText("Database Operation Error");
+                    alert.setContentText("Edit failed \n" +
+                            "the product-supplier link is already in the database");
+                    alert.showAndWait();
+                    numRows = -1; //Update numRow so alert only shows once
+                    closeStage(mouseEvent);
+                }
+                catch(SQLException e){
+                    throw new RuntimeException(e);
+                }
+            }
+
+            //if no rows were affected then there was an error (prompt user of error)
+            if (numRows == 0){
+                Alert alert = new Alert(Alert.AlertType.ERROR);
+                alert.setHeaderText("Database Operation Error");
+                alert.setContentText(mode + " failed");
+                alert.showAndWait();
+                closeStage(mouseEvent);
+            }
+            else if (numRows > 0){
+                //tell the user operation was successful
+                Alert alert = new Alert(Alert.AlertType.CONFIRMATION);
+                alert.setHeaderText("Database Operation Confirmed");
+                alert.setContentText(mode + " succeeded");
+                alert.showAndWait();
+                closeStage(mouseEvent);
+            }
+        }
+        else { //Display validation errors
+            Alert alert = new Alert(Alert.AlertType.ERROR);
+            alert.setHeaderText("Input Error");
+            alert.setContentText(errorMsg);
+            alert.showAndWait();
+        }
+    }
+
+    /**
+     * collect the data for new/updated productSupplier
+     * @return productSupplier entity with data
+     */
+    private ProductSupplier collectProductSupplier() {
+        ProductSupplier productSupplier = null;
+
+        productSupplier = new ProductSupplier(
+                cbSupplier.getSelectionModel().getSelectedItem().getSupId(),
+                cbProduct.getSelectionModel().getSelectedItem().getProdId(),
+                Double.parseDouble(txtCost.getText())
+        );
+
+        return productSupplier;
+    }
+
+    /**
+     * Display the productsupplier data in text fields and combobox
+     * @param productSupplier
+     */
+    public void displayProductSupplierDetails(ProductSupplierDTO productSupplier){
+        if(productSupplier != null){
+            txtCost.setText(productSupplier.getCost() + "");
+        }
+
+        //Get the right combobox selection (product)
+        for (Product product : cbProduct.getItems()) {
+            if(product.getProdId() == productSupplier.getProdId()){
+                cbProduct.getSelectionModel().select(product);
+            }
+        }
+
+        //Get the right combobox selection (supplier)
+        for (Supplier supplier : cbSupplier.getItems()) {
+            if (supplier.getSupId() == productSupplier.getSupId()) {
+                cbSupplier.getSelectionModel().select(supplier);
+            }
+        }
+
+    }
+
+    /**
+     * Close the window
+     * @param mouseEvent mouse event to close
+     */
+    private void closeStage(MouseEvent mouseEvent) {
+        Node node = (Node) mouseEvent.getSource();
+        Stage stage = (Stage) node.getScene().getWindow();
+        stage.close();
+    }
+
+    /**
+     * Set the mode of the dialog
+     * @param mode the mode for the dialog
+     */
+    public void setMode(String mode) {
+        this.mode = mode;
+        lblMode.setText(mode + " Product");
+        lblProductSupplierId.setVisible(false);
+    }
+
+    /**
+     * set the current supplier and productId for (needed for update since compound primary key)
+     * @param supId supplier id
+     * @param prodId product id
+     */
+    public void setSelectedIds(int supId, int prodId){
+        this.selectedSupId = supId;
+        this.selectedProdId = prodId;
+    }
+
+}

src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/SupplierDialogController.java

@@ -67,6 +67,11 @@ public class SupplierDialogController {
         });
     }
 
+    /**
+     * Validates the inputs, then add or update the database depending
+     * on the mode
+     * @param mouseEvent click event for save button
+     */
     private void buttonSaveClicked(MouseEvent mouseEvent) {
         int numRow = 0; //how many rows affected
         String errorMsg = ""; //error message for validation

src/main/java/org/example/petshopdesktop/database/ProductSupplierDB.java

@@ -0,0 +1,197 @@
+package org.example.petshopdesktop.database;
+
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import org.example.petshopdesktop.DTOs.ProductDTO;
+import org.example.petshopdesktop.DTOs.ProductSupplierDTO;
+import org.example.petshopdesktop.models.Product;
+import org.example.petshopdesktop.models.ProductSupplier;
+
+import java.sql.*;
+
+public class ProductSupplierDB {
+    /**
+     * gets all the productSupplier into an observable list
+     * @return a list of all the productSupplierDTOs
+     * @throws SQLException if failed to find productSupplier in the database
+     */
+    public static ObservableList<ProductSupplierDTO> getProductSupplierDTO() throws SQLException{
+        //Connect to the database
+        ObservableList<ProductSupplierDTO> productSuppliers = FXCollections.observableArrayList();
+        Connection conn = ConnectionDB.getConnection();
+
+        //Execute Query
+        Statement stmt = conn.createStatement();
+        String sql = "SELECT ps.supId, ps.prodId, s.supCompany, p.prodName, ps.cost " +
+                "FROM productsupplier ps " +
+                "LEFT JOIN product p " +
+                "ON p.prodId = ps.prodId " +
+                "LEFT JOIN supplier s " +
+                "ON s.supId = ps.supId";
+        ResultSet rs = stmt.executeQuery(sql);
+
+        //While there is still data add productSupplier to list
+        while(rs.next()){
+            ProductSupplierDTO productSupplier = new ProductSupplierDTO(
+                    rs.getInt(1),
+                    rs.getInt(2),
+                    rs.getString(3),
+                    rs.getString(4),
+                    rs.getDouble(5)
+            );
+            productSuppliers.add(productSupplier);
+        }
+
+        //close connection and return products
+        conn.close();
+        return productSuppliers;
+    }
+
+    /**
+     * Gets a list of ProductSupplierDTOs that is filtered by a given string
+     * @param filter the word to filter table
+     * @return ObservableList of ProductSupplierDTOs with the filtered data
+     * @throws SQLException if getting productSuppliers failed
+     */
+    public static ObservableList<ProductSupplierDTO> getFilteredProductSupplierDTO (String filter) throws SQLException {
+        //connect to the database
+        ObservableList<ProductSupplierDTO> productSuppliers = FXCollections.observableArrayList();
+        Connection conn = ConnectionDB.getConnection();
+
+        //Get SQL query for filter word
+        String sql =
+                "SELECT ps.supId, ps.prodId, s.supCompany, p.prodName, ps.cost " +
+                        "FROM product p " +
+                        "LEFT JOIN productsupplier ps " +
+                        "ON p.prodId = ps.prodId " +
+                        "LEFT JOIN supplier s " +
+                        "ON s.supId = ps.supId " +
+                        "WHERE " +
+                        "prodName LIKE ? OR " +
+                        "supCompany LIKE ? OR " +
+                        "cost LIKE ?";
+
+        //add % wildcard so query can use LIKE to filter data
+        String filteredString = "%" + filter + "%";
+
+        PreparedStatement stmt = conn.prepareStatement(sql);
+        stmt.setString(1, filteredString);
+        stmt.setString(2, filteredString);
+        stmt.setString(3, filteredString);
+
+        //execute query
+        ResultSet rs = stmt.executeQuery();
+
+        //While there is still data add productSupplier to the list
+        while(rs.next()){
+            ProductSupplierDTO productSupplier = new ProductSupplierDTO(
+                    rs.getInt(1),
+                    rs.getInt(2),
+                    rs.getString(3),
+                    rs.getString(4),
+                    rs.getDouble(5)
+            );
+            productSuppliers.add(productSupplier);
+        }
+
+        conn.close();
+        return productSuppliers;
+    }
+
+    /**
+     * Inserts a new productSupplier to the database
+     * @param productSupplier productSupplier entity to be inserted
+     * @return number of rows affected
+     * @throws SQLException if insert failed
+     */
+    public static int insertProductSupplier(ProductSupplier productSupplier) throws SQLException{
+        int numRows = 0;
+
+        Connection conn = ConnectionDB.getConnection();
+        String sql = "INSERT INTO productsupplier (prodId, supId, cost) " +
+                "VALUES (?, ?, ?)";
+
+        //These are the values from productSupplier to put into query above
+        PreparedStatement stmt = conn.prepareStatement(sql);
+        stmt.setInt(1, productSupplier.getProdId());
+        stmt.setInt(2, productSupplier.getSupId());
+        stmt.setDouble(3, productSupplier.getCost());
+
+        //update number of rows affected, return and close connection
+        numRows = stmt.executeUpdate();
+        conn.close();
+
+        return numRows;
+    }
+
+    /**
+     * Update a productSupplier by deleting old productSupplier and inserting new one
+     * @param oldProdId old product id (used to change primary compound key)
+     * @param oldSupId old supplier id (used to change primary compound key)
+     * @param productSupplier productSupplier entity with new info to update (including new primary compound key)
+     * @return number of rows affected in database
+     * @throws SQLException if update failed
+     */
+    public static int updateProductSupplier(int oldSupId, int oldProdId, ProductSupplier productSupplier) throws SQLException{
+        int numRows = 0;
+        Connection conn = ConnectionDB.getConnection();
+
+        //Make transaction so update can be rolled back if insert failed
+        conn.setAutoCommit(false);
+
+        try{
+            //Delete old data first
+            String sql = "DELETE FROM productsupplier WHERE supId = ? AND prodId = ?";
+            PreparedStatement stmt = conn.prepareStatement(sql);
+            stmt.setInt(1, oldSupId);
+            stmt.setInt(2, oldProdId);
+            numRows = stmt.executeUpdate();
+
+            //Then change the data by inserting a new relation with given keys (only if delete worked)
+            if(numRows > 0){
+                sql = "INSERT INTO productsupplier (prodId, supId, cost) " +
+                        "VALUES (?, ?, ?)";
+                stmt = conn.prepareStatement(sql);
+                stmt.setInt(1, productSupplier.getProdId());
+                stmt.setInt(2, productSupplier.getSupId());
+                stmt.setDouble(3, productSupplier.getCost());
+                numRows = stmt.executeUpdate();
+            }
+            //Commit changes if both delete and insert worked
+            conn.commit();
+        }
+        catch(SQLException e){
+            //Rollback CRUD failed
+            conn.rollback();
+            throw e;
+        }
+        finally {
+            //Set auto commit back to true before closing connection
+            conn.setAutoCommit(true);
+            conn.close();
+        }
+        return numRows;
+    }
+
+    /**
+     * Delete a productSupplier from the database
+     * @param prodId id of the product
+     * @param supId id of the supplier
+     * @return number of rows affected in the database
+     * @throws SQLException if delete failed
+     */
+    public static int deleteProductSupplier(int supId, int prodId) throws SQLException{
+        int numRows = 0;
+        Connection conn = ConnectionDB.getConnection();
+
+        String sql = "DELETE FROM productsupplier WHERE supId = ? AND prodId = ?";
+        PreparedStatement stmt = conn.prepareStatement(sql);
+        stmt.setInt(1, supId);
+        stmt.setInt(2, prodId);
+
+        numRows = stmt.executeUpdate();
+        conn.close();
+
+        return numRows;
+    }
+}

src/main/java/org/example/petshopdesktop/models/Product.java

@@ -83,4 +83,9 @@ public class Product {
     public void setProdDesc(String prodDesc) {
         this.prodDesc.set(prodDesc);
     }
+
+    @Override
+    public String toString() {
+        return getProdName();
+    }
 }

src/main/java/org/example/petshopdesktop/models/ProductSupplier.java

@@ -0,0 +1,54 @@
+package org.example.petshopdesktop.models;
+
+import javafx.beans.property.SimpleDoubleProperty;
+import javafx.beans.property.SimpleIntegerProperty;
+
+public class ProductSupplier {
+    private SimpleIntegerProperty supId;
+    private SimpleIntegerProperty prodId;
+    private SimpleDoubleProperty cost;
+
+    //constructor
+    public ProductSupplier(int supId, int prodId, double cost) {
+        this.supId = new  SimpleIntegerProperty(supId);
+        this.prodId = new SimpleIntegerProperty(prodId);
+        this.cost = new SimpleDoubleProperty(cost);
+    }
+
+    //getter and setters
+    public int getSupId() {
+        return supId.get();
+    }
+
+    public SimpleIntegerProperty supIdProperty() {
+        return supId;
+    }
+
+    public void setSupId(int supId) {
+        this.supId.set(supId);
+    }
+
+    public int getProdId() {
+        return prodId.get();
+    }
+
+    public SimpleIntegerProperty prodIdProperty() {
+        return prodId;
+    }
+
+    public void setProdId(int prodId) {
+        this.prodId.set(prodId);
+    }
+
+    public double getCost() {
+        return cost.get();
+    }
+
+    public SimpleDoubleProperty costProperty() {
+        return cost;
+    }
+
+    public void setCost(double cost) {
+        this.cost.set(cost);
+    }
+}

src/main/java/org/example/petshopdesktop/models/Supplier.java

@@ -106,4 +106,9 @@ public class Supplier {
     public String getSupFullName() {
         return getSupContactFirstName() + " " + getSupContactLastName();
     }
+
+    @Override
+    public String toString() {
+        return getSupCompany();
+    }
 }