I need count users in mysql using spring boot to display a statistic
my code content 3 class and interface :
////////////////interface////////////////////
public interface UserRepository extends JpaRepository<User, Long>
String count(String name);
////////////////service////////////////////
public String count(String username);
@Override
public String count(String username) {
return userRepository.count(username);
}
//////////////////iontroller////////////
@GetMapping("/count")
public String count(String username) {
return userService.count(username);
}
result in postman:
"message": "Failed to convert from type [java.lang.String] to type [java.lang.Long] for value 'count'; nested exception is java.lang.NumberFormatException: For input string: \"count\""
In the repository you need to use countBy
clause with searching field name and return long as return type. Assuming in User
entity username
is a field.
long countByUsername(String username);
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