How to update a row by id in jpa hibernate? - spring

Question

I was trying to update a row in db by fetching the idByName, but instead it's adding a new row? Please help me out.
This is my controller code:
#PostMapping("/retailer/update")
public ModelAndView updateRetailer(#ModelAttribute("retailer") Retailer retailerDetails)
{
System.out.println(retailerDetails.toString());
System.out.println("method called");
UUID id=repository.findIdByName(retailerDetails.getBusinessName());
System.out.println(retailerDetails.getBusinessName());
System.out.println(id);
String name=retailerDetails.getBusinessName();
System.out.println(name);
//Retailer retailer=repository.findOne(rid);
if(id == null)
{
return null;
}
retailerDetails.setBusinessName(retailerDetails.getBusinessName());
retailerDetails.setCity(retailerDetails.getCity());
retailerDetails.setIsActive(retailerDetails.getIsActive());
retailerDetails.setStartDate(retailerDetails.getStartDate());
retailerDetails.setUrl(retailerDetails.getUrl());
repository.save(retailerDetails);
return new ModelAndView("welcome");
}
This is my Repository code:
public interface RetailerRepository extends JpaRepository<Retailer, UUID>{
#Query("SELECT r.id FROM Retailer r where r.businessName=:name")
UUID findIdByName(#Param("name") String name);
}

Answer 1

You should forget to set the "id" to the retailerDetails entity. Spring JPA will only execute the update action when the primary key is set.
Added the following line in your code.
retailer.setId(id);
repository.save(retailer);

Answer 2

You should simply fetch by BusinessName.
Repository method be:
Retailer findByBusinessName(#Param("name") String name);
updateRetailer method be like:
Retailer retailer = findByBusinessName(retailerDetails.getBusinessName());
if(retailer!=null){
retailer.setBusinessName(retailerDetails.getBusinessName());
retailer.setCity(retailerDetails.getCity());
retailer.setIsActive(retailerDetails.getIsActive());
retailer.setStartDate(retailerDetails.getStartDate());
retailer.setUrl(retailerDetails.getUrl());
repository.save(retailer);
}

Answer 3

Your controller looks great and so is your repository. There is something that you should know when it comes to updating an entity with hibernate. Hibernate will save(create new object) if the id for the given item is null during the transaction and hibernate will save(update the current instance in the database) if the id exist.
The flow for this update I presume is when the request to update is requested, you retrieve the object based on the specified entity then return to the view. One thing to take note of is to carry your id with your even in the view.
Make sure you include the id in a hidden input like
from there the id will be submitted in addition to the updated data to the post method.
Most update issues similar to this can be fixed by versioning entity with the #Version
Use the format of the Spring Data JPA to successfully query without writing any query.
#Repository
public interface RetailerRepository extends JpaRepository{
// Assuming there is an attribute businessName in the Retailer entity.
UUID findByBusinessName(String businessName);
}