org.nuiton.topia.persistence

Interface TopiaQueryBuilderRunQueryWithUniqueResultStep<E extends TopiaEntity>

All Known Subinterfaces:

TopiaQueryBuilderAddCriteriaOrRunQueryStep<E>, TopiaQueryBuilderRunQueryStep<E>

All Known Implementing Classes:

AbstractTopiaDao.InnerTopiaQueryBuilderAddCriteriaOrRunQueryStep, AbstractTopiaDao.InnerTopiaQueryBuilderRunQueryStep

public interface TopiaQueryBuilderRunQueryWithUniqueResultStep<E extends TopiaEntity>

A subset of TopiaQueryBuilderRunQueryStep for certain API methods that should not allow findAll.

Since:

3.0

Author:

bleny

Method Summary

Modifier and Type	Method and Description
boolean	exists()
E	findUnique() Get the first element of a single-element result set.
E	findUniqueOrNull() Get the first element of a single-element result set or null if query result is empty.
com.google.common.base.Optional<E>	tryFindUnique() Get the first element of a single-element result set.

Method Detail

exists

boolean exists()

Returns:

true if the query returns at least one element

findUnique

E findUnique()
      throws TopiaNoResultException,
             TopiaNonUniqueResultException

Get the first element of a single-element result set.

Returns:

the first value from the set of result. Returned value can't be null

Throws:

TopiaNonUniqueResultException - if the query returns more than one element.

TopiaNoResultException - if the query does not return any result.

findUniqueOrNull

E findUniqueOrNull()
            throws TopiaNonUniqueResultException

Get the first element of a single-element result set or null if query result is empty. This method duplicates tryFindUnique() but allows you to prevent using Guava in you project.

Returns:

the first value from the set of result, or null of result set for given query is empty.

Throws:

TopiaNonUniqueResultException - if the query returns more than one element.

tryFindUnique

com.google.common.base.Optional<E> tryFindUnique()
                                          throws TopiaNonUniqueResultException

Get the first element of a single-element result set. If the call must return a result, prefer findUnique()

Returns:

the first value from the set of result. It's an optional because the query may return no result.

Throws:

TopiaNonUniqueResultException - if the query returns more than one element.