diff --git a/src/main/java/sg/com/smartinventory/controllers/CustomerController.java b/src/main/java/sg/com/smartinventory/controllers/CustomerController.java
index 3de76c3..9339dc7 100644
--- a/src/main/java/sg/com/smartinventory/controllers/CustomerController.java
+++ b/src/main/java/sg/com/smartinventory/controllers/CustomerController.java
@@ -2,6 +2,7 @@
 
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+// import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -10,6 +11,7 @@
 import jakarta.validation.Valid;
 
 import sg.com.smartinventory.entities.Customer;
+// import sg.com.smartinventory.entities.Review;
 import sg.com.smartinventory.services.CustomerService;
 
 @RestController
@@ -32,4 +34,12 @@ public ResponseEntity<Customer> createCustomer(@Valid @RequestBody Customer cust
         Customer newCustomer = customerService.createCustomer(customer);
         return new ResponseEntity<>(newCustomer, HttpStatus.CREATED);
     }
+
+    // // Nested route - Add review to customer.
+    // @PostMapping("/{id}/reviews")
+    // public ResponseEntity<Review> addReviewToCustomer(@PathVariable Long id,
+    // @Valid @RequestBody Review review) {
+    // Review newReview = customerService.addReviewToCustomer(id, review);
+    // return new ResponseEntity<>(newReview, HttpStatus.CREATED);
+    // }
 }
\ No newline at end of file
diff --git a/src/main/java/sg/com/smartinventory/controllers/ReviewController.java b/src/main/java/sg/com/smartinventory/controllers/ReviewController.java
index 11d627f..2681a6a 100644
--- a/src/main/java/sg/com/smartinventory/controllers/ReviewController.java
+++ b/src/main/java/sg/com/smartinventory/controllers/ReviewController.java
@@ -1,8 +1,14 @@
 package sg.com.smartinventory.controllers;
 
+import java.util.ArrayList;
+
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
@@ -31,4 +37,32 @@ public ResponseEntity<Review> createReview(@Valid @RequestBody Review review) {
         Review newReview = reviewService.createReview(review);
         return new ResponseEntity<>(newReview, HttpStatus.CREATED);
     }
+
+    // READ (GET ALL).
+    @GetMapping("")
+    public ResponseEntity<ArrayList<Review>> getAllReviews() {
+        ArrayList<Review> allReviews = reviewService.getAllReviews();
+        return new ResponseEntity<>(allReviews, HttpStatus.OK);
+    }
+
+    // READ (GET ONE).
+    @GetMapping("/{id}")
+    public ResponseEntity<Review> getReview(@PathVariable long id) {
+        Review foundReview = reviewService.getReview(id);
+        return new ResponseEntity<>(foundReview, HttpStatus.OK);
+    }
+
+    // UPDATE.
+    @PutMapping("/{id}")
+    public ResponseEntity<Review> updateReview(@PathVariable long id, @RequestBody Review review) {
+        Review updatedReview = reviewService.updateReview(id, review);
+        return new ResponseEntity<>(updatedReview, HttpStatus.OK);
+    }
+
+    // DELETE.
+    @DeleteMapping("/{id}")
+    public ResponseEntity<Review> deleteReview(@PathVariable long id) {
+        reviewService.deleteReview(id);
+        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/sg/com/smartinventory/serviceImpls/CustomerServiceImpl.java b/src/main/java/sg/com/smartinventory/serviceImpls/CustomerServiceImpl.java
index 70170a3..7ff203e 100644
--- a/src/main/java/sg/com/smartinventory/serviceImpls/CustomerServiceImpl.java
+++ b/src/main/java/sg/com/smartinventory/serviceImpls/CustomerServiceImpl.java
@@ -3,6 +3,8 @@
 import org.springframework.stereotype.Service;
 
 import sg.com.smartinventory.entities.Customer;
+// import sg.com.smartinventory.entities.Review;
+// import sg.com.smartinventory.exceptions.CustomerNotFoundException;
 import sg.com.smartinventory.repositories.CustomerRepository;
 import sg.com.smartinventory.services.CustomerService;
 
@@ -21,4 +23,19 @@ public Customer createCustomer(Customer customer) {
 
         return newCustomer;
     }
+
+    // @Override
+    // public Review addReviewToCustomer(long customerId, long productId, Review
+    // review) {
+    // // retrieve the customer from the database.
+    // Customer selectedCustomer =
+    // customerRepository.findById(customerId).orElseThrow(() -> new
+    // CustomerNotFoundException(customerId));
+
+    // // add the customer to the review
+    // review.setCustomer(selectedCustomer);
+
+    // // save the review to the database
+    // return reviewRepository.save(review);
+    // }
 }
\ No newline at end of file
diff --git a/src/main/java/sg/com/smartinventory/serviceImpls/ReviewServiceImpl.java b/src/main/java/sg/com/smartinventory/serviceImpls/ReviewServiceImpl.java
index d623ccc..29addfb 100644
--- a/src/main/java/sg/com/smartinventory/serviceImpls/ReviewServiceImpl.java
+++ b/src/main/java/sg/com/smartinventory/serviceImpls/ReviewServiceImpl.java
@@ -1,8 +1,12 @@
 package sg.com.smartinventory.serviceImpls;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import org.springframework.stereotype.Service;
 
 import sg.com.smartinventory.entities.Review;
+// import sg.com.smartinventory.exceptions.ReviewNotFoundException;
 import sg.com.smartinventory.repositories.ReviewRepository;
 import sg.com.smartinventory.services.ReviewService;
 
@@ -21,4 +25,58 @@ public Review createReview(Review review) {
 
         return newReview;
     }
+
+    @Override
+    public Review getReview(long id) {
+        // Optional<Review> optionalReview = reviewRepository.findById(id);
+        // if(optionalReview.isPresent()) {
+        // Review foundReview = optionalReview.get();
+        // return foundReview;
+        // }
+        // throw new ReviewNotFoundException(id);
+        // return reviewRepository.findById(id).orElseThrow(() -> new
+        // ReviewNotFoundException(id));
+        return reviewRepository.findById(id).get(0);
+    }
+
+    @Override
+    public ArrayList<Review> getAllReviews() {
+        List<Review> allReviews = reviewRepository.findAll();
+        return (ArrayList<Review>) allReviews;
+    }
+
+    @Override
+    public Review updateReview(long id, Review review) {
+        // Retrieve the review from the database.
+        // Review reviewToUpdate = reviewRepository.findById(id).orElseThrow(() -> new
+        // ReviewNotFoundException(id));
+        Review reviewToUpdate = reviewRepository.findById(id).get(0);
+
+        // Update the review retrieved from the database.
+        reviewToUpdate.setCategory(review.getCategory());
+        reviewToUpdate.setReviewContent(review.getReviewContent());
+        reviewToUpdate.setRating(review.getRating());
+        reviewToUpdate.setCustomerId(review.getCustomerId());
+        reviewToUpdate.setProductId(review.getProductId());
+
+        // Save the updated review back to the database.
+        return reviewRepository.save(reviewToUpdate);
+    }
+
+    @Override
+    public void deleteReview(long id) {
+        reviewRepository.deleteById(id);
+    }
+
+    @Override
+    public ArrayList<Review> searchCustomerReviews(long customerId) {
+        List<Review> foundReviews = reviewRepository.findByCustomerId(customerId);
+        return (ArrayList<Review>) foundReviews;
+    }
+
+    @Override
+    public ArrayList<Review> searchProductReviews(long productId) {
+        List<Review> foundReviews = reviewRepository.findByProductId(productId);
+        return (ArrayList<Review>) foundReviews;
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/sg/com/smartinventory/services/CustomerService.java b/src/main/java/sg/com/smartinventory/services/CustomerService.java
index d621136..c8d6e2a 100644
--- a/src/main/java/sg/com/smartinventory/services/CustomerService.java
+++ b/src/main/java/sg/com/smartinventory/services/CustomerService.java
@@ -1,7 +1,10 @@
 package sg.com.smartinventory.services;
 
 import sg.com.smartinventory.entities.Customer;
+// import sg.com.smartinventory.entities.Review;
 
 public interface CustomerService {
     Customer createCustomer(Customer customer);
+
+    // Review addReviewToCustomer(long customerId, long productId, Review review);
 }
\ No newline at end of file
diff --git a/src/main/java/sg/com/smartinventory/services/ReviewService.java b/src/main/java/sg/com/smartinventory/services/ReviewService.java
index ccb4c12..de37da9 100644
--- a/src/main/java/sg/com/smartinventory/services/ReviewService.java
+++ b/src/main/java/sg/com/smartinventory/services/ReviewService.java
@@ -1,7 +1,21 @@
 package sg.com.smartinventory.services;
 
+import java.util.ArrayList;
+
 import sg.com.smartinventory.entities.Review;
 
 public interface ReviewService {
     Review createReview(Review review);
+
+    Review getReview(long id);
+
+    ArrayList<Review> getAllReviews();
+
+    Review updateReview(long id, Review review);
+
+    void deleteReview(long id);
+
+    ArrayList<Review> searchCustomerReviews(long customerId);
+
+    ArrayList<Review> searchProductReviews(long productId);
 }
\ No newline at end of file