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How to store and display an SQL result where the columns do not match any of my entities

I am writing a spring boot application to perform certain jobs on a MySQL database. One of the things I am having trouble with is getting the average temperature per day from the database.
My #entity looks as follows:
#Entity
public class SensorData {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long sensorDataId;
#Column(
name = "timestamp"
)
private LocalDateTime timestamp;
#Column(
name = "temperature"
)
private Float temperature;
#Column(
name = "humidity"
)
private Float humidity;
#ManyToOne(
fetch = FetchType.LAZY,
optional = false,
cascade = CascadeType.ALL
)
#JoinColumn(
name = "department_id",
nullable = false
)
private Department department;
}
And department entity as follows. I am working with department (1)"A", (2)"B" and (3)"C".
#Entity
public class Department {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long departmentId;
#Column(
name = "department",
unique = true
)
private String department;
#OneToMany(
mappedBy = "department",
fetch = FetchType.LAZY
)
private List<SensorData> sensorData;
}
The problem I am facing is that I need to make a query that returns average temperature per day per department. In my attempts to do this I have written the following JpaRepository function:
#Query(value = "select round((dc.temperature),3) as temperature
,dc.department_id,dc.timestamp from db_uppg.sensor_data dc group by department_id,dc.timestamp",nativeQuery = true)
List<?> findTemperature();
And a controller function that returns a thymeleaf template averageTemperature.html:
#Controller
public class IndexController {
#Autowired
private SensorDataRepository sensorDataRepository;
#GetMapping("/averageHumidity")
public String avgHumidity(Model model) {
List<?> list = sensorDataRepository.findHumidity();
model.addAttribute("allHumidity", list);
return "averageHumidity";
}
}
And finally my thymeleaf template:
<table class="table table-dark table-hover">
<thead>
<tr>
<th scope="col">#</th>
<th scope="col">Average Temperature</th>
<th scope="col">Date</th>
</tr>
</thead>
<tbody>
<tr th:each="humidityList : ${allHumidity}">
<th scope="row">-</th>
<td th:text="${humidityList.humidity}"></td>
<td th:text="${humidityList.datetime}"></td>
</tr>
</tbody>
</table>
My IDE warns me that it cannot resolve humidity and datetime in my thymeleaf template. I assume it's because I am using List<?>, and Java cannot understand the data this list contains?
I am not sure what other ways I can achieve displaying a result where the columns requested do not match any of my original entities.

That query returns List<Object[]> as the actual type, so use that instead of ?. Then in your service layer (or the controller if you don't have a service layer), convert the rows to suitable DTOs with those fields (humidity and datetime).
The resulting code could look something like
List<HumidityDTO> list = sensorDataRepository.findHumidity().stream()
.map(h -> new (HumidityDTO(h)))
.collect(Collectors.toList());
If HumidityDTO has a constructor taking an Object[] parameter.

Display multiple rows in Thymeleaf table

I'm trying to create a table of attendees of my event using Thymeleaf on a Spring Boot app.
My table looks like this:
<table class="table table-bordered tabl-striped">
<thead class="thead-dark">
<th>First Name</th>
<th>Last Name</th>
</thead>
<tbody>
<tr th:each="tempEvent : ${event}">
<td th:text="${tempEvent.clubEventAttendees[event].firstName}" />
<td th:text="${tempEvent.clubEventAttendees[event].lastName}" />
</tr>
</tbody>
</table>
If I just use a single td with <td th:text="${tempEvent.clubEventAttendees}" /> I get this:
[EventAttendees [id=1, firstName=Paul, lastName=Jones], EventAttendees [id=2, firstName=Luke, lastName=Smyth]
This output contains the correct data. The above table however only outputs my second attendee(Luke Smyth). If I change the td lines to:
<td th:text="${tempEvent.clubEventAttendees[0].firstName}" />
<td th:text="${tempEvent.clubEventAttendees[0].lastName}" />
or
<td th:text="${tempEvent.clubEventAttendees[1].firstName}" />
<td th:text="${tempEvent.clubEventAttendees[1].lastName}" />
The correct person is displayed depending on their position. How can I change my table to display any attendees that get returned?
This is my Event model:
#Entity
#Table(name="club_events")
public class Event {
#OneToMany(mappedBy="clubEvent",
cascade={CascadeType.PERSIST, CascadeType.MERGE,
CascadeType.DETACH, CascadeType.REFRESH,
CascadeType.REMOVE})
private List<EventAttendees> clubEventAttendees;
// define fiends
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name="id")
private int id;
#Column(name="name")
private String name;
#Column(name="location")
private String location;
#Column(name="description")
private String description;
#DateTimeFormat(pattern="yyyy-MM-dd")
#Column(name="date_time")
private LocalDate dateTime;
public Event() {
}
public Event(int id, String name, String location, String description, LocalDate dateTime) {
super();
this.id = id;
this.name = name;
this.location = location;
this.description = description;
this.dateTime = dateTime;
}
}
This is my EventAttendees model:
#Entity
#Table(name="club_event_attendees")
public class EventAttendees {
#ManyToOne(cascade= {CascadeType.PERSIST, CascadeType.MERGE,
CascadeType.DETACH, CascadeType.REFRESH})
#JoinColumn(name="club_event_id")
private Event clubEvent;
// define fiends
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name="id")
private int id;
#Column(name="first_name")
private String firstName;
#Column(name="last_name")
private String lastName;
#Column(name="phone")
private String phone;
#Column(name="mobile")
private String mobile;
public EventAttendees() {
}
public EventAttendees(int id, String firstName, String lastName, String phone, String mobile, int clubEventId) {
super();
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.phone = phone;
this.mobile = mobile;
}
}
Note: getters and setters have been removed.
I currently have a page which lists all events(in a table):
The Attendees column will be removed once I get this figured out but if the View Attendees button is clicked I'd like to be taken to a page containing a similar table but with the firstName, lastName, phone and mobile of all attendees. Basically, I'd like to take the data returned in clubEventAttendees and display it in a table similar to the table above.

Okay so as promised, here is the code.
I can explain the example with Person and Car. The idea is that Person has List<Car>.
After pressing on View Cars, a new page is opened, where you see a list of Cars.
How to achieve this is fairly simple. When rendering List<Person> from modelAttribute people, you can use the following code
<tr th:each="person : ${people}">
<td th:text="${person.id}"></td>
<td th:text="${person.firstName}"></td>
<td th:text="${person.lastName}"></td>
<td>
<a th:href="#{'/person/' + ${person.id} + '/cars'}">View Cars</a>
</td>
</tr>
Href from th:href="#{'/person/' + ${person.id} + '/cars'}" executed following method in controller
#GetMapping("/person/{personId}/cars")
public String getCars(Model model, #PathVariable Integer personId){
model.addAttribute("cars", carRepository.findAllByPersonId(personId));
return "web/car-list";
}
after which a new template is rendered. I uploaded source code on GitHub, it can be found here https://github.com/Prebiusta/thymeleaf-playground
Hope it helps, let me know if there is something else.

Spring boot Thymeleaf populate dropdown list based on other dropdown list selections

How can I populate a dropdown list based on selections of other dropdown lists?
I have a Unit class, a Size class and a City class. The user must first select a country from a dropdown list of countries, the municipalities list will then display only the municipalities in that country, after that the user must select a city size, and at the end of it all, the user must select a city from a list of cities which are of the selected size, and belong to the selected municipality and country.
My code:
Unit.java
public class Unit {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(nullable=false)
private String name
#ManyToOne
#JoinColumn
#ToString.Exclude
private UnitType unitType;
#OneToOne
#JoinColumn
private Unit unit;
#OneToMany(mappedBy = "unit", cascade = CascadeType.ALL)
private Set<City> cities;
}
UnitType.java
public class UnitType {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(nullable=false)
#Enumerated(EnumType.STRING)
private UnitName uName;
#OneToMany(mappedBy = "unitType", cascade = CascadeType.ALL)
private Set<Unit> units;
public enum UnitName {
COUNTY, MUNICIPALITY
}
}
CitySize.java
public class CitySize {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(name="naziv", nullable=false)
#Enumerated(EnumType.STRING)
private Size name;
#OneToMany(mappedBy = "citySize", cascade = CascadeType.ALL)
private Set<City> sizes;
public enum Size {
SMALL, MEDIUM, LARGE
}
}
City.java
public class City {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(nullable=false)
private String name;
#ManyToOne
#JoinColumn
#ToString.Exclude
private CitySize citySize;
#ManyToOne
#JoinColumn
#ToString.Exclude
private Unit unit;
#OneToMany(mappedBy = "city", cascade = CascadeType.ALL)
private Set<Event> events;
}
Event.java
public class Event {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(nullable=false)
private String name;
#Column(nullable=false)
private LocalDateTime time;
#ManyToOne
#JoinColumn
#ToString.Exclude
private City city;
}
EventController.java
public class EventController {
....
#GetMapping("/citySearch")
public String citySearch(Model model) {
model.addAttribute("event", new Event());
model.addAttribute("unit", new Unit());
model.addAttribute("citySize", new CitySize());
model.addAttribute("counties", unitRepository.findByUnitTypeId(50001L));
model.addAttribute("municipalities", unitRepository.findByUnitTypeId(50002L));
model.addAttribute("sizes", CitySize.Size.values());
model.addAttribute("cities", cityRepository.findAll());
return "citySearch";
}
#PostMapping("/citySearch")
public String citySearch(Event event, Model model, City city, Unit unit,
CitySize citySize) {
List<Event> foundEvents = eventRepository.findByCity(city);
model.addAttribute("unit", new Unit());
model.addAttribute("citySize", new CitySize());
model.addAttribute("counties", unitRepository.findByUnitTypeId(50001L));
model.addAttribute("municipalities", unitRepository.findByUnitTypeId(50002L));
model.addAttribute("sizes", CitySize.Size.values());
model.addAttribute("cities", cityRepository.findAll());
model.addAttribute("foundEvents", foundEvents);
return "citySearch";
}
}
citySearch.html
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<link rel="stylesheet" type="text/css" th:href="#{/css/style.css}" >
<title>City search</title>
</head>
<body>
<h1>Event search by city</h1>
<form th:object="${unit}" method="post">
<div class="form-group">
<label for="unit">County: </label>
<select th:id="countyOption" th:field="*{unit}">
<option value="" >choose counties</option>
<option th:each="county : ${counties}" th:value="${county.id}" th:text="${county.name}"></option>
</select>
</div>
<div class="form-group">
<label for="unit">Municipality: </label>
<select th:id="municipalityOption" th:field="*{unit}">
<option value="" >choose municipilaties</option>
<option th:each="municipality : ${municipilaties}" th:value="${municipality.id}" th:text="${municipality.name}"></option>
</select>
</div>
</form>
<form th:object="${citySize}" method="post">
<div class="form-group">
<label for="name">City size: </label>
<select th:field="*{name}">
<option value="" >choose a city size</option>
<option th:each="name : ${sizes}" th:value="${id}" th:text="${name}"></option>
</select>
</div>
</form>
<form th:object="${event}" method="post">
<div class="form-group">
<label for="city">City: </label>
<select th:field="*{city}">
<option value="" >choose cities</option>
<option th:each="city : ${cities}" th:value="${city.id}" th:text="${city.name}"></option>
</select>
</div>
<input type="submit" th:value="Search">
</form>
<table>
<tr>
<th>Name</th>
<th>City</th>
<th>Time</th>
</tr>
<tr th:each="event : ${foundEvents}">
<td><span th:text="${event.name}" >EVENT.NAME</span></td>
<td><span th:text="${event.city.name}" >CITY.NAME</span></td>
<td><span th:text="${#temporals.format(event.time, 'dd.MM.yyyy. HH:mm')}" >EVENT.TIME</span></td>
</tr>
</table>
<p><a th:href="#{/search}">Return</a></p>
</body>
</html>
So far, my web search provided information that this can't be done by using only Spring boot and Thymeleaf, only with jQuery. Since I don't know jQuery, I would require some instructions on how to write and implement the method in jQuery. Also, I don't have a WebConfig.java class, since I had no need for it so far in my app, but if I need it now, what does it have to contain?

Spring Boot and Thymeleaf can't do anything client-side, but you can still achieve what you are trying to do without Javascript / JQuery:
You can submit the selected country to the backend, where you calculate the possible municipalities for that country, which you can add to the model and only display those (Or disable all other options). However, you will have to do that for every step that limits the options, that means reloading the page everytime, which can be painful to use.
If you want to accomplish the same without reloading the page, you will have to resort to some client-side code - that means Javascript / JQuery.

How to access attribute of attribute of object in thymeleaf?

Say I want to access an object that is called post. Post has a instance variable called Category of type Category.
In the Java controller class
model.addAttribute("posts", postRepository.findPostsByUser(user));
In the thymeleaf html file I have
<tr data-th-each="post : ${posts}">
I am wondering if it is it possible to access the below?
{post.category.name}
For clarification I have included the java classes below. Each instance has associated setters and getters.
#Entity
public class Post {
#ManyToOne
#JoinColumn(name = "category_id")
private Category category;
#Entity
public class Category {
private String name;

you have to make a condition:
<tr th:each="post:${posts}">
<td th:text="${post.category}!=null? ${post.category.name}:''"></td>
</tr>
:)

I think you need to change your entity code
#Entity
public class Post {
private Category category;
#ManyToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "category_id", nullable = false)
public Category getCategory () {
return this.category;
}
public void setCategory (Category category ) {
this.category = category ;
}
}
you need implement thymeleaf html page as per following
<tr th:each="post : ${posts}">
<td> <span th:utext="{post.category.name}" /></td>
</tr>
Hope its help to you!

Batch update returned unexpected row count from update (Spring/Hibernate)

Right now I have 3 tables in my database - Booking, Restaurant and RestaurantTable. I have a one to many mapping between Restaurant and RestaurantTable (a restaurant can have many tables, but a table can have only one restaurant). I have a file called "newTable.jsp" that inserts new tables to the restaurant. But when I try to do that it gives me the following error:
Request processing failed; nested exception is org.springframework.orm.hibernate4.HibernateOptimisticLockingFailureException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1; nested exception is org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
I think it's trying to access a RestaurantTable that does not exist yet? But I don't know how to fix that.
Here is my "Restaurant.java" class:
#Entity
#Table(name="restaurant")
public class Restaurant {
#Id
#Column(name="id")
#GeneratedValue(strategy= GenerationType.IDENTITY)
private Long id;
#Column(name="restaurant_name")
private String restaurantName;
#Column(name="address")
private String address;
#OneToMany(mappedBy="restaurant", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
private Set<RestaurantTable> table;
// Getters and setters
My "RestaurantTable.java":
#Entity
#Table(name="restaurant_table")
public class RestaurantTable {
#Id
#Column(name="id")
#GeneratedValue(strategy= GenerationType.IDENTITY)
private Long id;
#Column(name="table_size")
private int tableSize;
#Column(name="table_number")
private int tableNumber;
#ManyToOne
#JoinColumn(name="restaurant_id")
private Restaurant restaurant;
// Getters and setters
My "newTable.jsp"
<body>
<jsp:include page="../fragments/menu.jsp"/>
<div id="body">
<section class="content-wrapper main-content clear-fix">
<h2>Add New Table</h2>
<form:form method="POST" commandName="table" modelAttribute="table">
<table>
<tr>
<td>Table size:</td>
<td><form:input path="tableSize" /></td>
</tr>
<tr>
<td>Table number:</td>
<td><form:input path="tableNumber" /></td>
</tr>
<tr>
<td colspan="3"><input type="submit" />
</td>
</tr>
</table>
</form:form>
</section>
</div>
<jsp:include page="../fragments/footer.jsp"/>
</body>
My RestaurantTableController:
#Controller
public class RestaurantTableController {
#Autowired
private RestaurantService restaurantService;
#Autowired
private RestaurantTableService restaurantTableService;
#RequestMapping(value="restaurant/table/{id}", method = RequestMethod.GET)
public String addRestaurantTable(Model model) {
model.addAttribute("table", new RestaurantTable());
return "newTable";
}
#RequestMapping(value = "restaurant/table/{id}", method = RequestMethod.POST)
public String addRestaurantTable(#PathVariable Long id, #ModelAttribute ("table") RestaurantTable table) {
// Get a Restaurant object and add the table to it.
Restaurant restaurant = restaurantService.getRestaurant(id);
Set<RestaurantTable> tableSet = restaurant.getTable();
tableSet.add(table);
restaurant.setTable(tableSet);
restaurantService.updateRestaurant(restaurant);
return "editRestaurant";
}
}
The {id} in RestaurantTableController is a Restaurant id, it is passed along from "editRestaurant.jsp". Any help is appreciated.
EDIT: My updateRestaurant method:
#Override
public void updateRestaurant(Restaurant restaurant) {
Session session = this.sessionFactory.getCurrentSession();
session.update(restaurant);
logger.info("Restaurant record updated successfully, Restaurant Details=" + restaurant);
}

RestaurantTable entity doesn't have ID at that time, so hibernate throw exception. Try to use merge method instead of update
update
Update the persistent instance with the identifier of the given detached instance. If there is a persistent instance with the same identifier, an exception is thrown.