com.metamatrix.query.sql.symbol
Interface Expression

All Superinterfaces:

java.lang.Cloneable, LanguageObject, java.io.Serializable

All Known Implementing Classes:

AbstractCaseExpression, AggregateSymbol, AliasSymbol, CaseExpression, Constant, ElementSymbol, ExpressionSymbol, Function, Reference, ScalarSubquery, SearchedCaseExpression, SingleElementSymbol

public interface Expression
extends LanguageObject

This is the interface for an expression in a SQL string. Expressions can be of several types (see subclasses), but all expressions have a type. These types are used for type checking.

Method Summary

java.lang.Class	getType() Get the return type of this expression.
boolean	isResolved() Return true if expression has been fully resolved.

Methods inherited from interface com.metamatrix.query.sql.LanguageObject

acceptVisitor, clone

Method Detail

isResolved

boolean isResolved()

Return true if expression has been fully resolved. Typically the QueryResolver component will handle resolution of an expression.

Returns:

True if resolved

getType

java.lang.Class getType()

Get the return type of this expression. This method will not necessarily work right before resolution (isResolved() returns true).

Returns:

Java class name