uk.ac.ed.epcc.webapp.jdbc.expr

Class BinarySQLValue

java.lang.Object

uk.ac.ed.epcc.webapp.jdbc.expr.BinarySQLValue

All Implemented Interfaces:

GroupingSQLValue<java.lang.Number>, SQLValue<java.lang.Number>, Targetted<java.lang.Number>

public class BinarySQLValue
extends java.lang.Object
implements GroupingSQLValue<java.lang.Number>

a numerical binary SQLValue. Normally BinaryExpressions should be used in preference but this is needed if the arguments are SQLValues but not SQLExpressions

See Also:

BinaryExpression

Constructor Summary

Constructors

Constructor and Description
BinarySQLValue(AppContext conn, SQLValue<? extends java.lang.Number> a, Operator op, SQLValue<? extends java.lang.Number> b)

Method Summary

Modifier and Type	Method and Description
int	add(java.lang.StringBuilder sb, boolean qualify) Add the expression to a StringBuilder
int	addGroup(java.lang.StringBuilder sb, boolean qualify) Add the group-by clause to a query.
boolean	checkContentsCanGroup() return false if this instance is not able to perform grouping.
protected SQLValue<? extends java.lang.Number>	getA()
protected SQLValue<? extends java.lang.Number>	getB()
java.util.List<PatternArgument>	getGroupParameters(java.util.List<PatternArgument> list) Get the parameters for a group-by clause.
java.util.List<PatternArgument>	getParameters(java.util.List<PatternArgument> list) Add parameters for this value to a list.
SQLFilter	getRequiredFilter() Get an SQLFilter required to be added to the filter set.
java.lang.Class<java.lang.Number>	getTarget() Get the type of the returned object as far as it is known.
java.lang.Number	makeObject(java.sql.ResultSet rs, int pos) Extract a result of the expression from a ResultSet into an object of the specified type.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface uk.ac.ed.epcc.webapp.jdbc.expr.GroupingSQLValue

groupingIsomorphic

Constructor Detail

BinarySQLValue

public BinarySQLValue(AppContext conn,
                      SQLValue<? extends java.lang.Number> a,
                      Operator op,
                      SQLValue<? extends java.lang.Number> b)

Method Detail

add

public final int add(java.lang.StringBuilder sb,
                     boolean qualify)

Description copied from interface: SQLValue

Add the expression to a StringBuilder

Specified by:

add in interface SQLValue<java.lang.Number>

Parameters:

sb - StringBuilder to modify

qualify - boolean should fields be qualified with the table name

Returns:

number of fields added

makeObject

public final java.lang.Number makeObject(java.sql.ResultSet rs,
                                         int pos)
                                  throws DataException,
                                         java.sql.SQLException

Description copied from interface: SQLValue

Extract a result of the expression from a ResultSet into an object of the specified type. Note that this method is also used to extract the result of functions over the result type.

Specified by:

makeObject in interface SQLValue<java.lang.Number>

Parameters:

rs - ResultSet

Returns:

produced object

Throws:

DataException

java.sql.SQLException

getTarget

public final java.lang.Class<java.lang.Number> getTarget()

Description copied from interface: Targetted

Get the type of the returned object as far as it is known. Normally this should be the erasure type corresponding to T.

Specified by:

getTarget in interface Targetted<java.lang.Number>

Returns:

Class object for return type

toString

public final java.lang.String toString()

Overrides:

toString in class java.lang.Object

getRequiredFilter

public final SQLFilter getRequiredFilter()

Description copied from interface: SQLValue

Get an SQLFilter required to be added to the filter set. This is usually to implement a join.

Specified by:

getRequiredFilter in interface SQLValue<java.lang.Number>

Returns:

null or SQLFilter

getParameters

public final java.util.List<PatternArgument> getParameters(java.util.List<PatternArgument> list)

Description copied from interface: SQLValue

Add parameters for this value to a list.

Specified by:

getParameters in interface SQLValue<java.lang.Number>

Parameters:

list - to modify

Returns:

modified list of parameter objects

getA

protected SQLValue<? extends java.lang.Number> getA()

Returns:

the a

getB

protected SQLValue<? extends java.lang.Number> getB()

Returns:

the b

addGroup

public int addGroup(java.lang.StringBuilder sb,
                    boolean qualify)

Description copied from interface: GroupingSQLValue

Add the group-by clause to a query. Note this can be a null operation in which case it will return zero.

Specified by:

addGroup in interface GroupingSQLValue<java.lang.Number>

Returns:

actual number of fields added

getGroupParameters

public java.util.List<PatternArgument> getGroupParameters(java.util.List<PatternArgument> list)

Description copied from interface: GroupingSQLValue

Get the parameters for a group-by clause.

Specified by:

getGroupParameters in interface GroupingSQLValue<java.lang.Number>

Returns:

modified list

checkContentsCanGroup

public boolean checkContentsCanGroup()

Description copied from interface: GroupingSQLValue

return false if this instance is not able to perform grouping.

Specified by:

checkContentsCanGroup in interface GroupingSQLValue<java.lang.Number>

Returns: