de.fuberlin.wiwiss.d2rq.algebra

Interface ProjectionSpec

All Superinterfaces:

Comparable<ProjectionSpec>

All Known Implementing Classes:

Attribute, ExpressionProjectionSpec

public interface ProjectionSpec
extends Comparable<ProjectionSpec>

Something to be used in the SELECT clause of a SQL query, e.g. a column name or an expression.

Author:

Richard Cyganiak (richard@cyganiak.de)

Method Summary

Methods

Modifier and Type	Method and Description
Expression	notNullExpression(ConnectedDB database, AliasMap aliases)
ProjectionSpec	renameAttributes(ColumnRenamer renamer)
Set<Attribute>	requiredAttributes()
Expression	toExpression()
String	toSQL(ConnectedDB database, AliasMap aliases)

Methods inherited from interface java.lang.Comparable

compareTo

Method Detail

requiredAttributes

Set<Attribute> requiredAttributes()

renameAttributes

ProjectionSpec renameAttributes(ColumnRenamer renamer)

toExpression

Expression toExpression()

toSQL

String toSQL(ConnectedDB database,
           AliasMap aliases)

notNullExpression

Expression notNullExpression(ConnectedDB database,
                           AliasMap aliases)