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

java.lang.Object
  org.apache.openjpa.jdbc.kernel.exps.AbstractVal
      org.apache.openjpa.jdbc.kernel.exps.CoalesceExpression

All Implemented Interfaces:

Serializable, Val, Value

public class CoalesceExpression
extends AbstractVal

Coalesce expression.

Author:

Catalina Wei

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.openjpa.jdbc.kernel.exps.AbstractVal

FALSE, TRUE

Fields inherited from interface org.apache.openjpa.jdbc.kernel.exps.Val

ABS_VAL, ARGS_VAL, CMP_EQUAL, COALESCE_VAL, CONCAT_VAL, FORCE_OUTER, GENERALCASE_VAL, INDEXOF_VAL, JOIN_REL, LENGTH_VAL, LOCATE_VAL, LOWER_VAL, MATH_VAL, NULL_CMP, NULLIF_VAL, SIMPLECASE_VAL, SQRT_VAL, SUBSTRING_VAL, TRIM_VAL, UPPER_VAL, VAL, WHENCONDITION_VAL, WHENSCALAR_VAL

Constructor Summary

CoalesceExpression(Val[] vals)
Constructor.

Method Summary

void	acceptVisit(ExpressionVisitor visitor) Accept a visit from a tree visitor.
void	appendTo(Select sel, ExpContext ctx, ExpState state, SQLBuffer buf, int index) Append the indexth SQL element to the given buffer.
void	calculateValue(Select sel, ExpContext ctx, ExpState state, Val other, ExpState otherState) Calculate and cache the SQL for this value.
int	getId()
ClassMetaData	getMetaData() Return any associated persistent type.
Value	getOtherPath()
ExpState	getOtherState()
Class	getType() Return the expected type for this value, or Object if the type is unknown.
Val[]	getVal()
void	groupBy(Select sel, ExpContext ctx, ExpState state) Group by this value.
ExpState	initialize(Select sel, ExpContext ctx, int flags) Initialize the value.
int	length(Select sel, ExpContext ctx, ExpState state) Return the number of SQL elements in this value.
Object	load(ExpContext ctx, ExpState state, Result res) Load the data for this value.
void	orderBy(Select sel, ExpContext ctx, ExpState state, boolean asc) Order by this value.
void	select(Select sel, ExpContext ctx, ExpState state, boolean pks) Select the data for this value.
void	selectColumns(Select sel, ExpContext ctx, ExpState state, boolean pks) Select just the columns for this value.
void	setImplicitType(Class type) Set the implicit type of the value, based on how it is used in the filter.
void	setMetaData(ClassMetaData meta) Associate a persistent type with this value.
void	setOtherPath(Value other)
void	setOtherState(ExpState otherState)

Methods inherited from class org.apache.openjpa.jdbc.kernel.exps.AbstractVal

appendIndex, appendIsEmpty, appendIsNotEmpty, appendIsNotNull, appendIsNull, appendSize, appendType, getAlias, getName, getPath, getSelectAs, isAggregate, isVariable, isXPath, setAlias, toDataStoreValue

Methods inherited from class java.lang.Object

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

Constructor Detail

CoalesceExpression

public CoalesceExpression(Val[] vals)

Constructor.

Method Detail

getVal

public Val[] getVal()

getType

public Class getType()

Description copied from interface: Value

Return the expected type for this value, or Object if the type is unknown.

initialize

public ExpState initialize(Select sel,
                           ExpContext ctx,
                           int flags)

Description copied from interface: Val

Initialize the value. This method should recursively initialize any sub-values.

appendTo

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

Description copied from interface: Val

Append the indexth SQL element to the given buffer.

selectColumns

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

Description copied from interface: Val

Select just the columns for this value.

acceptVisit

public void acceptVisit(ExpressionVisitor visitor)

Description copied from interface: Value

Accept a visit from a tree visitor.

Specified by:

acceptVisit in interface Value

Overrides:

acceptVisit in class AbstractVal

getId

public int getId()

Specified by:

getId in interface Val

Overrides:

getId in class AbstractVal

calculateValue

public void calculateValue(Select sel,
                           ExpContext ctx,
                           ExpState state,
                           Val other,
                           ExpState otherState)

Description copied from interface: Val

Calculate and cache the SQL for this value. This method is called before length or any append methods.

other - the value being compared to, or null if not a comparison

groupBy

public void groupBy(Select sel,
                    ExpContext ctx,
                    ExpState state)

Description copied from interface: Val

Group by this value.

length

public int length(Select sel,
                  ExpContext ctx,
                  ExpState state)

Description copied from interface: Val

Return the number of SQL elements in this value.

load

public Object load(ExpContext ctx,
                   ExpState state,
                   Result res)
            throws SQLException

Description copied from interface: Val

Load the data for this value.

Throws:

SQLException

orderBy

public void orderBy(Select sel,
                    ExpContext ctx,
                    ExpState state,
                    boolean asc)

Description copied from interface: Val

Order by this value.

select

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

Description copied from interface: Val

Select the data for this value.

getMetaData

public ClassMetaData getMetaData()

Description copied from interface: Value

Return any associated persistent type.

setImplicitType

public void setImplicitType(Class type)

Description copied from interface: Value

Set the implicit type of the value, based on how it is used in the filter. This method is only called on values who return Object from Value.getType().

setMetaData

public void setMetaData(ClassMetaData meta)

Description copied from interface: Value

Associate a persistent type with this value.

setOtherPath

public void setOtherPath(Value other)

getOtherPath

public Value getOtherPath()

setOtherState

public void setOtherState(ExpState otherState)

getOtherState

public ExpState getOtherState()