Hibernate Error Invalid Column Name - spring

Question

I am trying to make a one to many and many to one relation in hibernate and spring.
below is my code for product class
import java.io.Serializable;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToOne;
import javax.persistence.Table;
#Entity
#Table(name="Product")
public class Product implements Serializable{
#Id
#Column(name="productId")
#GeneratedValue
private Integer productId;
#Column(name="productName")
private String productName;
#Column(name="productPrice")
private int productPrice;
//---------------------------------------item mapped to category------------------------------------------//
#ManyToOne(cascade = CascadeType.ALL,fetch = FetchType.EAGER)
#JoinTable(
name="CategoryProduct",
joinColumns= #JoinColumn(name="productId")
)
private Category category;
//--------------------------------------------------------------------------------------------------------//
public Integer getProductId() {
return productId;
}
public void setProductId(Integer productId) {
this.productId = productId;
}
public String getProductName() {
return productName;
}
public void setProductName(String productName) {
this.productName = productName;
}
public int getProductPrice() {
return productPrice;
}
public void setProductPrice(int productPrice) {
this.productPrice = productPrice;
}
public Category getCategory() {
return category;
}
public void setCategory(Category category) {
this.category = category;
}
}
below is my code for category class
import java.util.Set;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import java.io.Serializable;
#Entity
#Table(name="Category")
public class Category implements Serializable{
#Id
#Column(name="categoryId")
#GeneratedValue
private Integer categoryId;
#Column(name="categoryName")
private String categoryName;
#OneToMany(cascade=CascadeType.ALL,fetch=FetchType.EAGER)
#JoinTable(
name="CategoryProduct",
joinColumns = #JoinColumn(name="categoryId"),
inverseJoinColumns = #JoinColumn(name="productId")
)
public Set<Product> product;
public Integer getCategoryId() {
return categoryId;
}
public void setCategoryId(Integer categoryId) {
this.categoryId = categoryId;
}
public String getCategoryName() {
return categoryName;
}
public void setCategoryName(String categoryName) {
this.categoryName = categoryName;
}
public Set<Product> getProduct() {
return product;
}
public void setProduct(Set<Product> product) {
this.product = product;
}
}
Whenever i run the code i am getting Invalid column name 'category_categoryId'.
Structure of my tables
Product has column as productId, poductName and productPrice
category has columns as categoryId, categoryName
categoryproducts has columns as categoryId and productId

Answer 1

you forgot to put inverseJoinColumns at your #JoinTable in Product Class. This cause hibernate to use their convention of joinTable which is <ClassName>_<columnName>. Change it to
#JoinTable(
name="CategoryProduct",
joinColumns = #JoinColumn(name="productId"),
inverseJoinColumns = #JoinColumn(name="categoryId")
)
private Category category;
However, seeing at your design, you are actually creating 2 uni-directional association between product and category. If you want to create bi-directional association, I suggest you change the One side (Category), to use mappedBy
#OneToMany(mappedBy="category", cascade=CascadeType.ALL,fetch=FetchType.EAGER)
public Set<Product> product;
It will generally achieve the same result. Hope it helps!