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
 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)