org.modeshape.jcr.api.query.qom
Interface SetQueryObjectModel

All Superinterfaces:

Query, QueryCommand, SetQuery

All Known Implementing Classes:

JcrSetQueryObjectModel

public interface SetQueryObjectModel
extends SetQuery, Query

A set query extension to the JCR query object model.

The JCR query object model describes the queries that can be evaluated by a JCR repository independent of any particular query language, such as SQL. JCR defines the QueryObjectModel interface as the primary representatino of this query object model, but this interface is not sufficient for certain queries, such as unions or intersections of other queries. This interface is an extension to the JCR API that mirrors the QueryObjectModel interface for set queries.

A query consists of:

• a source. When the query is evaluated, the source evaluates its selectors and the joins between them to produce a (possibly empty) set of node-tuples. This is a set of 1-tuples if the query has one selector (and therefore no joins), a set of 2-tuples if the query has two selectors (and therefore one join), a set of 3-tuples if the query has three selectors (two joins), and so forth.
• an optional constraint. When the query is evaluated, the constraint filters the set of node-tuples.
• a list of zero or more orderings. The orderings specify the order in which the node-tuples appear in the query results. The relative order of two node-tuples is determined by evaluating the specified orderings, in list order, until encountering an ordering for which one node-tuple precedes the other. If no orderings are specified, or if for none of the specified orderings does one node-tuple precede the other, then the relative order of the node-tuples is implementation determined (and may be arbitrary).
• a list of zero or more columns to include in the tabular view of the query results. If no columns are specified, the columns available in the tabular view are implementation determined, but minimally include, for each selector, a column for each single-valued non-residual property of the selector's node type.

The query object model representation of a query is created by factory methods in the QueryObjectModelFactory.

See Also:

QueryObjectModel

Field Summary

Fields inherited from interface javax.jcr.query.Query

JCR_JQOM, JCR_SQL2, SQL, XPATH

Method Summary

Methods inherited from interface org.modeshape.jcr.api.query.qom.SetQuery

getLeft, getOperation, getRight, isAll

Methods inherited from interface org.modeshape.jcr.api.query.qom.QueryCommand

getColumns, getLimits, getOrderings

Methods inherited from interface javax.jcr.query.Query

bindValue, execute, getBindVariableNames, getLanguage, getStatement, getStoredQueryPath, setLimit, setOffset, storeAsNode