Refactory User Repository to Query for firstName

src/main/java/com/MongoDemo/MongoSpring/model/UserReq.java

@@ -8,18 +8,18 @@ import org.springframework.data.annotation.Id;
 public class UserReq {
 
     @JsonProperty
-    private String Id;
+    private String userId;
     @JsonProperty
     private String firstName;
     @JsonProperty
     private String lastName;
 
     public String getId() {
-        return Id;
+        return userId;
     }
 
     public void setId(String id) {
-        Id = id;
+        userId = id;
     }
 
     public String getFirstName() {

src/main/java/com/MongoDemo/MongoSpring/repository/UserRepository.java

@@ -12,6 +12,6 @@ public interface UserRepository extends MongoRepository<User, String> {
 
     void deleteByUserId(String userId);
 
-    @Query("{'userFirstName' : ?0}")
+    @Query("{'firstName' : ?0}")
     List<User> findByUserFirstName(String userFirstName);
 }