org.springframework.data.jpa.repository.query

Interface QueryEnhancer

All Known Implementing Classes:

DefaultQueryEnhancer, JSqlParserQueryEnhancer

public interface QueryEnhancer

This interface describes the API for enhancing a given Query.

Since:

2.7.0

Author:

Diego Krupitza, Greg Turnquist

Method Summary

Modifier and Type	Method and Description
default String	applySorting(Sort sort) Adds order by clause to the JPQL query.
String	applySorting(Sort sort, String alias) Adds order by clause to the JPQL query.
default String	createCountQueryFor() Creates a count projected query from the given original query.
String	createCountQueryFor(String countProjection) Creates a count projected query from the given original query using the provided countProjection.
String	detectAlias() Resolves the alias for the entity to be retrieved from the given JPA query.
Set<String>	getJoinAliases()
String	getProjection() Returns the projection part of the query, i.e. everything between select and from.
org.springframework.data.jpa.repository.query.DeclaredQuery	getQuery() Gets the query we want to use for enhancements.
default boolean	hasConstructorExpression() Returns whether the given JPQL query contains a constructor expression.

Method Detail

applySorting

default String applySorting(Sort sort)

Adds order by clause to the JPQL query. Uses the first alias to bind the sorting property to.

Parameters:

sort - the sort specification to apply.

Returns:

the modified query string.

applySorting

String applySorting(Sort sort,
                    @Nullable
                    String alias)

Adds order by clause to the JPQL query.

Parameters:

sort - the sort specification to apply.

alias - the alias to be used in the order by clause. May be null or empty.

Returns:

the modified query string.

detectAlias

@Nullable
String detectAlias()

Resolves the alias for the entity to be retrieved from the given JPA query.

Returns:

Might return null.

createCountQueryFor

default String createCountQueryFor()

Creates a count projected query from the given original query.

Returns:

Guaranteed to be not null.

createCountQueryFor

String createCountQueryFor(@Nullable
                           String countProjection)

Creates a count projected query from the given original query using the provided countProjection.

Parameters:

countProjection - may be null.

Returns:

a query String to be used a count query for pagination. Guaranteed to be not null.

hasConstructorExpression

default boolean hasConstructorExpression()

Returns whether the given JPQL query contains a constructor expression.

Returns:

whether the given JPQL query contains a constructor expression.

getProjection

String getProjection()

Returns the projection part of the query, i.e. everything between select and from.

Returns:

the projection part of the query.

getJoinAliases

Set<String> getJoinAliases()

getQuery

org.springframework.data.jpa.repository.query.DeclaredQuery getQuery()

Gets the query we want to use for enhancements.

Returns:

non-null DeclaredQuery that wraps the query