com.blazebit.persistence.view

Interface CorrelationProvider

public interface CorrelationProvider

Provides correlation functionality for entity views. Beware that correlation providers may only be used once for an entity view hierarchy. Also note that aliases defined in the query builder will contribute to the main query when using FetchStrategy.JOIN, so be careful and choose rather unique names.

Since:

1.2.0

Author:

Christian Beikov

Method Summary

Modifier and Type	Method and Description
void	applyCorrelation(CorrelationBuilder correlationBuilder, String correlationExpression) Applies a correlation to a query builder.

Method Detail

applyCorrelation

void applyCorrelation(CorrelationBuilder correlationBuilder,
                      String correlationExpression)

Applies a correlation to a query builder. Depending on the correlation strategy, the correlationExpression may be one of the following:

• FetchStrategy.SELECT - A named parameter
• FetchStrategy.SUBSELECT - A named collection parameter
• FetchStrategy.JOIN - The correlation expression

To be able to make use of all strategies it is best if you use the IN predicate in conjunction with the correlationExpression.

Parameters:

correlationBuilder - The correlation builder to create the correlation

correlationExpression - The correlation expression from the outer query on which to correlate