JPA Criteria API Queries

The JPA Criteria API provides an alternative way for defining JPA queries, which is mainly useful for building dynamic queries whose exact structure is only known at runtime.

JPA Criteria API vs JPQL

JPQL queries are defined as strings, similarly to SQL. JPA criteria queries, on the other hand, are defined by the instantiation of Java objects that represent query elements.

A major advantage of using the criteria API is that errors can be detected earlier, during compilation rather than at runtime. On the other hand, for many developers string based JPQL queries, which are very similar to SQL queries, are easier to use and understand.

For simple static queries - string based JPQL queries (e.g. as named queries) may be preferred. For dynamic queries that are built at runtime - the criteria API may be preferred.

For example, building a dynamic query based on fields that a user fills at runtime in a form that contains many optional fields - is expected to be cleaner when using the JPA criteria API, because it eliminates the need for building the query using many string concatenation operations.

String based JPQL queries and JPA criteria based queries are equally powerful and efficient. Therefore, choosing one method over the other is also a matter of personal preference. 

First JPA Criteria Query

The following query string represents a minimal JPQL query:

SELECT c FROM Country c

An equivalent query can be built using the JPA criteria API as follows:

  CriteriaBuilderjakarta.persistence.criteria.CriteriaBuilderUsed to construct criteria queries, compound selections, expressions, predicates, orderings. cb = em.getCriteriaBuilderjakarta.persistence.EntityManager.getCriteriaBuilder()Obtain an instance of CriteriaBuilder which may be used to construct CriteriaQuery<T> objects.();

  CriteriaQueryjakarta.persistence.criteria.CriteriaQueryThe CriteriaQuery interface defines functionality that is specific to top-level queries.<Country> q = cb.createQueryjakarta.persistence.criteria.CriteriaBuilder.createQuery(Class)Create a CriteriaQuery<T> object with the given result type.(Country.class);
  Rootjakarta.persistence.criteria.RootA root type in the from clause.<Country> c = q.fromjakarta.persistence.criteria.AbstractQuery.from(Class)Create and add a query root corresponding to the given entity, forming a cartesian product with any existing roots.(Country.class);
  q.selectjakarta.persistence.criteria.CriteriaQuery.select(Selection)Specify the item that is to be returned in the query result.(c);

The CriteriaBuilderjakarta.persistence.criteria.CriteriaBuilderUsed to construct criteria queries, compound selections, expressions, predicates, orderings. interface serves as the main factory of criteria queries and criteria query elements. It can be obtained either by the EntityManagerFactoryjakarta.persistence.EntityManagerFactoryInterface used to interact with the persistence unit, and to create new instances of EntityManager.'s getCriteriaBuilderjakarta.persistence.EntityManagerFactory.getCriteriaBuilder()Return an instance of CriteriaBuilder which may be used to construct CriteriaQuery<T> objects. method or by the EntityManagerjakarta.persistence.EntityManagerInterface used to interact with the persistence context.'s getCriteriaBuilderjakarta.persistence.EntityManager.getCriteriaBuilder()Obtain an instance of CriteriaBuilder which may be used to construct CriteriaQuery<T> objects. method (both methods are equivalent).

In the example above a CriteriaQueryjakarta.persistence.criteria.CriteriaQueryThe CriteriaQuery interface defines functionality that is specific to top-level queries. instance is created for representing the built query. Then a Rootjakarta.persistence.criteria.RootA root type in the from clause. instance is created to define a range variable in the FROM clause. Finally, the range variable, c, is also used in the SELECT clause as the query result expression. CriteriaQueryTypedQueryjakarta.persistence.TypedQueryInterface used to control the execution of typed queries.TypedQuery

  TypedQueryjakarta.persistence.TypedQueryInterface used to control the execution of typed queries.<Country> query = em.createQueryjakarta.persistence.EntityManager.createQuery(CriteriaQuery)Create an instance of TypedQuery<X> for executing a criteria query.(q);
  List<Country> results = query.getResultListjakarta.persistence.Query.getResultList()Execute a SELECT query and return the query results as an untyped List<E>.();

Using the criteria API introduces some extra work, at least for simple static queries, since the equivalent JPQL query could simply be executed as follows:

  TypedQueryjakarta.persistence.TypedQueryInterface used to control the execution of typed queries.<Country> query =
      em.createQueryjakarta.persistence.EntityManager.createQuery(String,Class)Create an instance of TypedQuery<X> for executing a Jakarta Persistence query language statement.("SELECT c FROM Country c", Country.class);
  List<Country> results = query.getResultListjakarta.persistence.Query.getResultList()Execute a SELECT query and return the query results as an untyped List<E>.();

Because eventually both types of queries are represented by a TypedQueryjakarta.persistence.TypedQueryInterface used to control the execution of typed queries. instance - query execution and query setting is similar, regardless of the way in which the query is built.

Parameters in Criteria Queries

The following query string represents a JPQL query with a parameter:

SELECT c FROM Country c WHERE c.population > :p

An equivalent query can be built using the JPA criteria API as follows:

  CriteriaBuilderjakarta.persistence.criteria.CriteriaBuilderUsed to construct criteria queries, compound selections, expressions, predicates, orderings. cb = em.getCriteriaBuilderjakarta.persistence.EntityManager.getCriteriaBuilder()Obtain an instance of CriteriaBuilder which may be used to construct CriteriaQuery<T> objects.();

  CriteriaQueryjakarta.persistence.criteria.CriteriaQueryThe CriteriaQuery interface defines functionality that is specific to top-level queries.<Country> q = cb.createQueryjakarta.persistence.criteria.CriteriaBuilder.createQuery(Class)Create a CriteriaQuery<T> object with the given result type.(Country.class);
  Rootjakarta.persistence.criteria.RootA root type in the from clause.<Country> c = q.fromjakarta.persistence.criteria.AbstractQuery.from(Class)Create and add a query root corresponding to the given entity, forming a cartesian product with any existing roots.(Country.class);
  ParameterExpressionjakarta.persistence.criteria.ParameterExpressionType of criteria query parameter expressions.<Integer> p = cb.parameterjakarta.persistence.criteria.CriteriaBuilder.parameter(Class)Create a parameter expression.(Integer.class);
  q.selectjakarta.persistence.criteria.CriteriaQuery.select(Selection)Specify the item that is to be returned in the query result.(c).wherejakarta.persistence.criteria.CriteriaQuery.where(Expression)Modify the query to restrict the query result according to the specified boolean expression.(cb.gtjakarta.persistence.criteria.CriteriaBuilder.gt(Expression,Expression)Create a predicate for testing whether the first argument is greater than the second.(c.getjakarta.persistence.criteria.Path.get(String)Create a path corresponding to the referenced attribute.("population"), p));

The ParameterExpressionjakarta.persistence.criteria.ParameterExpressionType of criteria query parameter expressions. instance, p, is created to represent the query parameter. The wherejakarta.persistence.criteria.CriteriaQuery.where(Expression)Modify the query to restrict the query result according to the specified boolean expression. method sets the WHERE clause. As shown above, The CriteriaQueryjakarta.persistence.criteria.CriteriaQueryThe CriteriaQuery interface defines functionality that is specific to top-level queries. interface supports method chaining. See the links in the next sections of this page for detailed explanations on how to set criteria query clauses and build criteria expressions.

Running this query requires setting the parameter:

  TypedQueryjakarta.persistence.TypedQueryInterface used to control the execution of typed queries.<Country> query = em.createQueryjakarta.persistence.EntityManager.createQuery(CriteriaQuery)Create an instance of TypedQuery<X> for executing a criteria query.(q);
  query.setParameterjakarta.persistence.Query.setParameter(Parameter,T)Bind the value of a Parameter object.(p, 10000000);
  List<Country> results = query.getResultListjakarta.persistence.Query.getResultList()Execute a SELECT query and return the query results as an untyped List<E>.();

The setParameterjakarta.persistence.Query.setParameter(Parameter,T)Bind the value of a Parameter object. method takes a Parameterjakarta.persistence.ParameterType for query parameter objects. (or a ParameterExpressionjakarta.persistence.criteria.ParameterExpressionType of criteria query parameter expressions.) instance as the first argument instead of a name or a position (which are used with string based JPQL parameters).

Criteria Query Structure

Queries in JPA (as in SQL) are composed of clauses. Because JPQL queries and criteria queries use equivalent clauses - they are explained side by side in the Query Structure pages.

Specific details about criteria query clauses are provided in the following page sections:

• SELECT clause (selectjakarta.persistence.criteria.CriteriaQuery.select(Selection)Specify the item that is to be returned in the query result., distinctjakarta.persistence.criteria.CriteriaQuery.distinct(boolean)Specify whether duplicate query results are eliminated., multiselectjakarta.persistence.criteria.CriteriaQuery.multiselect(Selection...)Specify the selection items that are to be returned in the query result., arrayjakarta.persistence.criteria.CriteriaBuilder.array(Selection...)Create an array-valued selection item., tuplejakarta.persistence.criteria.CriteriaBuilder.tuple(Selection...)Create a tuple-valued selection item., constructjakarta.persistence.criteria.CriteriaBuilder.construct(Class,Selection...)Create a selection item corresponding to a constructor.).
• FROM clause (fromjakarta.persistence.criteria.AbstractQuery.from(Class)Create and add a query root corresponding to the given entity, forming a cartesian product with any existing roots., joinjakarta.persistence.criteria.From.join(String,JoinType)Create a join to the specified attribute using the given join type., fetchjakarta.persistence.criteria.FetchParent.fetch(String)Create a fetch join to the specified attribute using an inner join.).
• WHERE clause (wherejakarta.persistence.criteria.CriteriaQuery.where(Predicate...)Modify the query to restrict the query result according to the conjunction of the specified restriction predicates.).
• GROUP BY / HAVING clauses (groupByjakarta.persistence.criteria.CriteriaQuery.groupBy(Expression...)Specify the expressions that are used to form groups over the query results., havingjakarta.persistence.criteria.CriteriaQuery.having(Expression)Specify a restriction over the groups of the query., countjakarta.persistence.criteria.CriteriaBuilder.count(Expression)Create an aggregate expression applying the count operation., sumjakarta.persistence.criteria.CriteriaBuilder.sum(Expression)Create an aggregate expression applying the sum operation., avgjakarta.persistence.criteria.CriteriaBuilder.avg(Expression)Create an aggregate expression applying the avg operation., minjakarta.persistence.criteria.CriteriaBuilder.min(Expression)Create an aggregate expression applying the numerical min operation., maxjakarta.persistence.criteria.CriteriaBuilder.max(Expression)Create an aggregate expression applying the numerical max operation., ...).
• ORDER BY clause (orderByjakarta.persistence.criteria.CriteriaQuery.orderBy(Order...)Specify the ordering expressions that are used to order the query results., Orderjakarta.persistence.criteria.OrderAn object that defines an ordering over the query results., ascjakarta.persistence.criteria.CriteriaBuilder.asc(Expression)Create an ordering by the ascending value of the expression., descjakarta.persistence.criteria.CriteriaBuilder.desc(Expression)Create an ordering by the descending value of the expression.).

The links above are direct links to the criteria query sections in pages that describe query structure in general, including in the context of string based JPQL queries.

Criteria Query Expressions

JPA query clauses are composed of expressions. Because JPQL queries and criteria queries use equivalent expressions - they are explained side by side in the Query Expressions pages.

Specific details about criteria query expressions are provided in the following page sections:

• Literals and Dates (literaljakarta.persistence.criteria.CriteriaBuilder.literal(T)Create an expression for a literal., nullLiteraljakarta.persistence.criteria.CriteriaBuilder.nullLiteral(Class)Create an expression for a null literal with the given type., currentDatejakarta.persistence.criteria.CriteriaBuilder.currentDate()Create expression to return current date., ...).
• Paths, navigation and types (getjakarta.persistence.criteria.Path.get(String)Create a path corresponding to the referenced attribute., typejakarta.persistence.criteria.Path.type()Create an expression corresponding to the type of the path.).
• Arithmetic expressions (sumjakarta.persistence.criteria.CriteriaBuilder.sum(Expression,Expression)Create an expression that returns the sum of its arguments., diffjakarta.persistence.criteria.CriteriaBuilder.diff(Expression,Expression)Create an expression that returns the difference between its arguments., prodjakarta.persistence.criteria.CriteriaBuilder.prod(Expression,Expression)Create an expression that returns the product of its arguments., quotjakarta.persistence.criteria.CriteriaBuilder.quot(Expression,Expression)Create an expression that returns the quotient of its arguments., modjakarta.persistence.criteria.CriteriaBuilder.mod(Expression,Expression)Create an expression that returns the modulus (remainder under integer division) of its arguments., absjakarta.persistence.criteria.CriteriaBuilder.abs(Expression)Create an expression that returns the absolute value of its argument., negjakarta.persistence.criteria.CriteriaBuilder.neg(Expression)Create an expression that returns the arithmetic negation of its argument., sqrtjakarta.persistence.criteria.CriteriaBuilder.sqrt(Expression)Create an expression that returns the square root of its argument.).
• String expressions (likejakarta.persistence.criteria.CriteriaBuilder.like(Expression,Expression)Create a predicate for testing whether the expression satisfies the given pattern., lengthjakarta.persistence.criteria.CriteriaBuilder.length(Expression)Create expression to return length of a string., locatejakarta.persistence.criteria.CriteriaBuilder.locate(Expression,Expression)Create expression to locate the position of one string within another, returning position of first character if found., lowerjakarta.persistence.criteria.CriteriaBuilder.lower(Expression)Create expression for converting a string to lowercase., upperjakarta.persistence.criteria.CriteriaBuilder.upper(Expression)Create expression for converting a string to uppercase., concatjakarta.persistence.criteria.CriteriaBuilder.concat(Expression,Expression)Create an expression for string concatenation., substringjakarta.persistence.criteria.CriteriaBuilder.substring(Expression,Expression)Create an expression for substring extraction., ...).
• Collection expressions (isEmptyjakarta.persistence.criteria.CriteriaBuilder.isEmpty(Expression)Create a predicate that tests whether a collection is empty., isNotEmptyjakarta.persistence.criteria.CriteriaBuilder.isNotEmpty(Expression)Create a predicate that tests whether a collection is not empty., isMemberjakarta.persistence.criteria.CriteriaBuilder.isMember(Expression,Expression)Create a predicate that tests whether an element is a member of a collection., isNotMemberjakarta.persistence.criteria.CriteriaBuilder.isNotMember(Expression,Expression)Create a predicate that tests whether an element is not a member of a collection., sizejakarta.persistence.criteria.CriteriaBuilder.size(Expression)Create an expression that tests the size of a collection.).
• Comparison expressions (equaljakarta.persistence.criteria.CriteriaBuilder.size(Expression)Create an expression that tests the size of a collection., notEqualjakarta.persistence.criteria.CriteriaBuilder.notEqual(Expression,Expression)Create a predicate for testing the arguments for inequality., gtjakarta.persistence.criteria.CriteriaBuilder.gt(Expression,Expression)Create a predicate for testing whether the first argument is greater than the second., gejakarta.persistence.criteria.CriteriaBuilder.ge(Expression,Expression)Create a predicate for testing whether the first argument is greater than or equal to the second., ltjakarta.persistence.criteria.CriteriaBuilder.lt(Expression,Expression)Create a predicate for testing whether the first argument is less than the second., lejakarta.persistence.criteria.CriteriaBuilder.le(Expression,Expression)Create a predicate for testing whether the first argument is less than or equal to the second., betweenjakarta.persistence.criteria.CriteriaBuilder.between(Expression,Expression,Expression)Create a predicate for testing whether the first argument is between the second and third arguments in value., isNulljakarta.persistence.criteria.CriteriaBuilder.isNull(Expression)Create a predicate to test whether the expression is null., ...)
• Logical expressions (andjakarta.persistence.criteria.CriteriaBuilder.and(Expression,Expression)Create a conjunction of the given boolean expressions., orjakarta.persistence.criteria.CriteriaBuilder.or(Expression,Expression)Create a disjunction of the given boolean expressions., notjakarta.persistence.criteria.CriteriaBuilder.not(Expression)Create a negation of the given restriction., isTruejakarta.persistence.criteria.CriteriaBuilder.isTrue(Expression)Create a predicate testing for a true value.).

The links above are direct links to the criteria query sections in pages that describe expressions in general, including in the context of string based JPQL queries.