JpaRepository

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✅ Common Spring Data JPA Query Keywords

Keyword	Meaning	Example Method
And, Or	Logical conjunction/disjunction	findByFirstNameAndLastName
Is, Equals	Exact match	findByEmailIs(String email)
Not	Negation	findByFirstNameNot(String name)
In, NotIn	Collection match	findByIdIn(List<String> ids)
Like	SQL LIKE, % must be added manually	findByEmailLike(String pattern)
Contains	LIKE %x%	findByEmailContaining(String part)
StartsWith	LIKE x%	findByEmailStartingWith(String prefix)
EndsWith	LIKE %x	findByEmailEndingWith(String suffix)
IgnoreCase	Case-insensitive match	findByFirstNameIgnoreCase(String name)
GreaterThan	> comparison	findByAgeGreaterThan(int age)
LessThan	< comparison	findByAgeLessThan(int age)
Between	Range	findByCreatedAtBetween(start, end)
Before, After	Date/time comparisons	findByUpdatedAtAfter(LocalDateTime dt)
IsNull, NotNull	Check for null values	findByPhoneNumberIsNull()
True, False	Boolean flags	findByActiveTrue()

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🧰 Dynamic Queries: Spring Data Specifications

For dynamic filtering (e.g. search by optional fields), use JPA Specifications.

✅ Step 1: Extend JpaSpecificationExecutor

public interface UserRepository extends 
    BaseRepository<User, String>, 
    JpaSpecificationExecutor<User> {
}

✅ Step 2: Create a Specification<User>

public class UserSpecifications {
 
    public static Specification<User> hasFirstName(String name) {
        return (root, query, cb) ->
            cb.equal(root.get("firstName"), name);
    }
 
    public static Specification<User> emailContains(String fragment) {
        return (root, query, cb) ->
            cb.like(cb.lower(root.get("email")), "%" + fragment.toLowerCase() + "%");
    }
}

✅ Step 3: Use It Dynamically

Specification<User> spec = Specification.where(null);
 
if (firstName != null) {
    spec = spec.and(UserSpecifications.hasFirstName(firstName));
}
 
if (emailFragment != null) {
    spec = spec.and(UserSpecifications.emailContains(emailFragment));
}
 
List<User> users = userRepository.findAll(spec);

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🚀 When to Use

Use Case	Approach
Simple lookups	Method naming
Optional/multiple filters	Specifications
Complex joins, subqueries	@Query or Criteria

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Let me know if you want:

• A ready-to-use dynamic UserSearchRequest + filter logic

• Integration of Specifications in your service layer

• Paginated dynamic filtering with sorting