Menu
Requirement - For Recipe application, user can input Recipe Name and Ingredients. User can input more than one ingredient of a recipe on the JSP page.
Database Model: Created 2 tables. (Recipe can have more than one Ingredient)
Recipe -
recipe_id (primary key)
name
Ingredient
ingredient_id (primary key)
recipe_id (foreign key to recipe(recipe_id))
quantity
ingredient
Issue - For this case, @OneToMany (as shown below) is used for Hibernate mapping but when user save the form, foreign key (i.e. recipe_id) is not getting stored in the Ingredient table. Say user inputs following:
Recipe - Sandwich
Ingredient - 250g(as quantity) Salt (as ingredient)
After saving following is getting saved (i.e. No value in the recipe table)
**Recipe**
recipe_id - 1
name - Sandwich
**Ingredient**
ingredient_id - 50
recipe_id - NULL
quantity - 250g
ingredient - Salt
There is no error while saving form.
Following is saved in log by Hibernate when user save the data:
Hibernate: select seq_recipe.nextval from dual
Hibernate: select seq_ingredient.nextval from dual
Hibernate: insert into RECIPE (NAME, RECIPE_ID) values (?, ?)
Hibernate: insert into ingredient (COMMENTS, INGREDIENT, RECIPE_ID, INGREDIENT_ID) values (?, ?, ?, ?)
Oracle table
create table ingredient(ingredient_id number(4) primary key,
quantity varchar2(20),
ingredient varchar2(40),
recipe_id number(4),
constraint recipe_fk foreign key (recipe_id)
references recipe(recipe_id));
create table recipe(id number primary key,
name varchar2(25) unique,
ingredient_id number(4),
constraint ingredient_fk foreign key(ingredient_id)
references ingredient(ingredient_id));
Ingredient and Recipe POJO
@Entity
@Table(name = "ingredient", uniqueConstraints={
@UniqueConstraint(columnNames="INGREDIENT_ID")
})
public class Ingredient implements Serializable {
private static final long serialVersionUID = -2489479702169761646L;
@Id
@Column(name = "INGREDIENT_ID", unique=true, nullable=false)
@SequenceGenerator(name="seq_ingredient", sequenceName="seq_ingredient")
@GeneratedValue(strategy=GenerationType.AUTO, generator="seq_ingredient")
private Integer ingredientId;
@Column(name = "QUANTITY")
private String quantity;
@Column(name = "INGREDIENT")
private String ingredient;
@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name="RECIPE_ID", nullable=false)
private Recipe recipe;
//getter and setters
@Entity
@Table(name = "recipe")
public class Recipe implements Serializable {
private static final long serialVersionUID = 4398676897855994030L;
@Id
@Column(name = "id")
private Integer id;
@Column(name = "name")
private String name;
@OneToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER, mappedBy="recipe")
private List<Ingredient> ingredients;
//getters and setter
}
MVC that will map the /add url and also handle POST method, when user save the data
@RequestMapping("/add")
public String newRecipe(Model model) {
Recipe recipe = new Recipe();
recipe.setIngredients(new AutoPopulatingList<Ingredient>(Ingredient.class));
model.addAttribute("recipe", recipe);
return "recipes/new";
}
@RequestMapping(value = "add", method = RequestMethod.POST)
public String addRecipe(@Valid Recipe recipe, BindingResult result,
Model model) {
if (result.hasErrors()) {
return "recipes/new";
}
recipeServices.addRecipe(recipe);
return "redirect:/recipe/" + recipe.getId();
}
**DAO to save Recipe objec **
public class RecipeDaoImpl implements RecipeDao {
public void addRecipe(Recipe recipe) {
getSession().save(recipe);
}
}
JSP code
<html>
<script type="text/javascript">
<!--
function addRow(tableID) {
<!-- Code delete to improve readability. Dynamically add row -->
}
-->
</script>
</head>
<body>
<s:url value="/recipe/add" var="recipe_new" />
<sf:form modelAttribute="recipe" action="${recipe_new}" method="POST">
<table>
<tr>
<th>Recipe Name:</th>
<td><sf:input path="name" id="recipeName" /> <br />
<sf:errors path="name" cssClass="error" /></td>
</tr>
<tr>
<td>
<h3>Ingredients</h3> <INPUT type="button" value="+"
onclick="addRow('dataTable')" /> <INPUT type="button" value="-"
onclick="deleteRow('dataTable')" />
<table id="dataTable" width="350px" border="1">
<tr>
<th></th>
<th>Quantity</th>
<th>Ingredient</th>
</tr>
<tr>
<td><input type="checkbox" name="chk" /></td>
<td><sf:input type="text" path="ingredients[0].quantity"
title="Quantity" placeholder="Quantity" /></td>
<td><sf:input type="text" path="ingredients[0].ingredient"
title="Ingredient" placeholder="Ingredient" /></td>
</tr>
</table>
</td>
</tr>
</table>
</sf:form>
</body>
</html>
Humble request to help me as I have been trying to fix this issue from past 2 days and not able to understand why foreign key not getting stored in database.
731
asked Sep 06 '25 13:09
mappedBy is generally for bidirection relationship, to save extra queries for updation/insertion.
Basically for OneToMany on Parent side and ManyToOne on Child Side.
In your case, mappedBy means that Parent does not hold responsibility to save references to Child.
So try using @JoinColumn in your case.
72
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
