org.datanucleus.query.typesafe

Interface TypesafeSubquery<T>

Type Parameters:

T - (Candidate) type being represented

All Known Implementing Classes:

JDOTypesafeSubquery

public interface TypesafeSubquery<T>

Interface for a type-safe subquery, using a fluent API. Users should call methods on the subquery instance and end with a select of what the subquery returns; this returns the expression that they use to link it with the owning query.

Method Summary

Methods

Modifier and Type	Method and Description
PersistableExpression	candidate() Method to return an expression for the candidate of the subquery.
TypesafeSubquery	filter(BooleanExpression expr) Method to set the filter of the query.
TypesafeSubquery	groupBy(Expression... exprs) Method to set the grouping(s) for the query.
TypesafeSubquery	having(Expression expr) Method to set the having clause of the query.
CollectionExpression	select(CollectionExpression expr) Accessor for the subquery (collection) expression from the subquery.
CharacterExpression	selectUnique(CharacterExpression expr) Accessor for the subquery (character) expression from the subquery when the subquery returns a single value.
<S> DateExpression<S>	selectUnique(DateExpression<S> expr) Accessor for the subquery (date) expression from the subquery when the subquery returns a single value.
<S> DateTimeExpression<S>	selectUnique(DateTimeExpression<S> expr) Accessor for the subquery (datetime) expression from the subquery when the subquery returns a single value.
<S> NumericExpression<S>	selectUnique(NumericExpression<S> expr) Accessor for the subquery (numeric) expression from the subquery when the subquery returns a single value.
StringExpression	selectUnique(StringExpression expr) Accessor for the subquery (string) expression from the subquery when the subquery returns a single value.
<S> TimeExpression<S>	selectUnique(TimeExpression<S> expr) Accessor for the subquery (time) expression from the subquery when the subquery returns a single value.

Method Detail

candidate

PersistableExpression candidate()

Method to return an expression for the candidate of the subquery. Cast the returned expression to the candidate "Q" type to be able to call methods on it.

Returns:

Expression for the candidate

filter

TypesafeSubquery filter(BooleanExpression expr)

Method to set the filter of the query.

Parameters:

expr - Filter expression

Returns:

The query

groupBy

TypesafeSubquery groupBy(Expression... exprs)

Method to set the grouping(s) for the query.

Parameters:

exprs - Grouping expression(s)

Returns:

The query

having

TypesafeSubquery having(Expression expr)

Method to set the having clause of the query.

Parameters:

expr - Having expression

Returns:

The query

selectUnique

<S> NumericExpression<S> selectUnique(NumericExpression<S> expr)

Accessor for the subquery (numeric) expression from the subquery when the subquery returns a single value.

Type Parameters:

S - numeric type

Parameters:

expr - The expression

Returns:

Expression for the typesafe query

selectUnique

StringExpression selectUnique(StringExpression expr)

Accessor for the subquery (string) expression from the subquery when the subquery returns a single value.

Parameters:

expr - The expression

Returns:

Expression for the typesafe query

selectUnique

<S> DateExpression<S> selectUnique(DateExpression<S> expr)

Accessor for the subquery (date) expression from the subquery when the subquery returns a single value.

Type Parameters:

S - date type

Parameters:

expr - The expression

Returns:

Expression for the typesafe query

selectUnique

<S> DateTimeExpression<S> selectUnique(DateTimeExpression<S> expr)

Accessor for the subquery (datetime) expression from the subquery when the subquery returns a single value.

Type Parameters:

S - datetime type

Parameters:

expr - The expression

Returns:

Expression for the typesafe query

selectUnique

<S> TimeExpression<S> selectUnique(TimeExpression<S> expr)

Accessor for the subquery (time) expression from the subquery when the subquery returns a single value.

Type Parameters:

S - time type

Parameters:

expr - The expression

Returns:

Expression for the typesafe query

selectUnique

CharacterExpression selectUnique(CharacterExpression expr)

Accessor for the subquery (character) expression from the subquery when the subquery returns a single value.

Parameters:

expr - The expression

Returns:

Expression for the typesafe query

select

CollectionExpression select(CollectionExpression expr)

Accessor for the subquery (collection) expression from the subquery.

Parameters:

expr - The expression

Returns:

Expression for the typesafe query