org.apache.openjpa.jdbc.kernel.exps
Class CompareExpression

java.lang.Object
  org.apache.openjpa.jdbc.kernel.exps.CompareExpression

All Implemented Interfaces:

Serializable, Exp, Expression

 class CompareExpression
extends Object
implements Exp

Compares two values.

Author:

Abe White

Field Summary

static String	GREATER
static String	GREATER_EQUAL
static String	LESS
static String	LESS_EQUAL

Constructor Summary

CompareExpression(Val val1, Val val2, String op)
Constructor.

Method Summary

void	acceptVisit(ExpressionVisitor visitor) Accept a visit from a tree visitor.
void	appendTo(Select sel, ExpContext ctx, ExpState state, SQLBuffer buf) Append the SQL for this expression to the given buffer.
ExpState	initialize(Select sel, ExpContext ctx, Map contains) Initialize the expression.
void	selectColumns(Select sel, ExpContext ctx, ExpState state, boolean pks) Select just the columns for this expression.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LESS

public static final String LESS

See Also:

Constant Field Values

GREATER

public static final String GREATER

See Also:

Constant Field Values

LESS_EQUAL

public static final String LESS_EQUAL

See Also:

Constant Field Values

GREATER_EQUAL

public static final String GREATER_EQUAL

See Also:

Constant Field Values

Constructor Detail

CompareExpression

public CompareExpression(Val val1,
                         Val val2,
                         String op)

Constructor. Supply values and operator.

Method Detail

initialize

public ExpState initialize(Select sel,
                           ExpContext ctx,
                           Map contains)

Description copied from interface: Exp

Initialize the expression. This method should recursively initialize any sub-expressions or values.

Specified by:

initialize in interface Exp

contains - map of relation paths to the number of times the paths appear in a contains() expression; used to ensure paths used for contains() within the same AND expression used different aliases

appendTo

public void appendTo(Select sel,
                     ExpContext ctx,
                     ExpState state,
                     SQLBuffer buf)

Description copied from interface: Exp

Append the SQL for this expression to the given buffer. The SQL should optionally include any joins this expression needs.

Specified by:

appendTo in interface Exp

selectColumns

public void selectColumns(Select sel,
                          ExpContext ctx,
                          ExpState state,
                          boolean pks)

Description copied from interface: Exp

Select just the columns for this expression.

Specified by:

selectColumns in interface Exp

acceptVisit

public void acceptVisit(ExpressionVisitor visitor)

Description copied from interface: Expression

Accept a visit from a tree visitor.

Specified by:

acceptVisit in interface Expression