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

Class SQLGroupMapper<O>

java.lang.Object

uk.ac.ed.epcc.webapp.AbstractContexed

uk.ac.ed.epcc.webapp.jdbc.expr.SQLGroupMapper<O>

Type Parameters:

O - Type being produced

All Implemented Interfaces:

Contexed, ResultMapper<O>

Direct Known Subclasses:

GeneralMapMapper, RangeSearch.InfoMapper, TableMapper

public abstract class SQLGroupMapper<O>
extends AbstractContexed
implements ResultMapper<O>

A base class for ResultMappers that use SQL Group-By queries there are methods to add various select clauses to the target string.

See Also:

GroupingSQLValue

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	qualify
protected boolean	use_alias

Fields inherited from class uk.ac.ed.epcc.webapp.AbstractContexed

conn

Constructor Summary

Constructors

Constructor and Description
SQLGroupMapper(AppContext c) Make a TableMapper

Method Summary

Modifier and Type	Method and Description
void	addAverage(SQLExpression<? extends java.lang.Number> field, java.lang.String name) Add a column average to the table output
<T> SQLValue<T>	addClause(SQLValue<T> orig, java.lang.String name) Add a column to the table output
<T> void	addCount(GroupingSQLValue<T> expr, java.lang.String name) Add a column counting distinct values.
void	addCount(java.lang.String name)
void	addKey(GroupingSQLValue<?> exp, java.lang.String name) add a field both as a clause and as an group by key Note the SQLValue can implement GroupingSQLValue to customise behaviours.
protected boolean	addKeyList(java.lang.StringBuilder sb) add group by clauses corresponding to key list
void	addMaxDate(SQLExpression<? extends java.util.Date> field, java.lang.String name) Add a column max date to the table output
void	addMaxNumber(SQLExpression<? extends java.lang.Number> field, java.lang.String name) Add a column max to the table output
void	addMinDate(SQLExpression<? extends java.util.Date> field, java.lang.String name) Add a column min date to table output
void	addMinNumber(SQLExpression<? extends java.lang.Number> field, java.lang.String name) Add a column min to the table output
void	addSQLAverage(SQLExpression<? extends java.lang.Number> field, java.lang.String name) Add a column AVG to the table output The average is applied in SQL so cannot be combined/merged with other groups or other queries.
<T> void	addSQLCount(SQLValue<T> expr, java.lang.String name) Add a column counting distinct values.
void	addSum(SQLExpression<? extends java.lang.Number> field, java.lang.String name) Add a column sum to the table output
java.lang.String	getModify() provide an override GROUP/ORDER by clause null to use default order from filters
java.util.List<PatternArgument>	getModifyParameters(java.util.List<PatternArgument> list) Add parameters for the GROUP/ORDER clause to a list.
SQLFilter	getRequiredFilter() Get an additional Filter required to make the target string work properly.
java.lang.String	getTarget() get the target clause of the SQL query.
protected java.lang.Object	getTargetObject(int index, java.sql.ResultSet rs)
java.util.List<PatternArgument>	getTargetParameters(java.util.List<PatternArgument> list) Add parameters for the target clause to a list.
boolean	setQualify(boolean qualify) Request that field names should be qualified with the table name where appropriate.
void	setUseAlias(boolean val)

Methods inherited from class uk.ac.ed.epcc.webapp.AbstractContexed

getContext, getLogger, resetLogger

Methods inherited from class java.lang.Object

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

Methods inherited from interface uk.ac.ed.epcc.webapp.jdbc.filter.ResultMapper

makeDefault, makeObject

Field Detail

qualify

protected boolean qualify

use_alias

protected boolean use_alias

Constructor Detail

SQLGroupMapper

public SQLGroupMapper(AppContext c)

Make a TableMapper

Parameters:

c - AppContext

Method Detail

setQualify

public boolean setQualify(boolean qualify)

Description copied from interface: ResultMapper

Request that field names should be qualified with the table name where appropriate. This is for use with joined tables. For some result mappers this does not make sense so this method always returns the same value.

Specified by:

setQualify in interface ResultMapper<O>

Returns:

previous value of qualify flag

setUseAlias

public void setUseAlias(boolean val)

getTargetObject

protected java.lang.Object getTargetObject(int index,
                                           java.sql.ResultSet rs)
                                    throws DataException,
                                           java.sql.SQLException

Throws:

DataException

java.sql.SQLException

addKey

public void addKey(GroupingSQLValue<?> exp,
                   java.lang.String name)
            throws InvalidKeyException

add a field both as a clause and as an group by key Note the SQLValue can implement GroupingSQLValue to customise behaviours. Literal constants are not legal in group-by clauses so GroupingSQLValue must be implemented when the SQL representation is a constant.

Parameters:

exp -

name -

Throws:

InvalidKeyException

addClause

public <T> SQLValue<T> addClause(SQLValue<T> orig,
                                 java.lang.String name)

Add a column to the table output

Type Parameters:

T - java type produced

Parameters:

orig - Expression to evaluate

name - name of resultant column

Returns:

SQLValue used to refer to this clause

addSum

public final void addSum(SQLExpression<? extends java.lang.Number> field,
                         java.lang.String name)

Add a column sum to the table output

Parameters:

field - field to sum

name - name for result column

addAverage

public final void addAverage(SQLExpression<? extends java.lang.Number> field,
                             java.lang.String name)

Add a column average to the table output

Parameters:

field - field to average

name - name for result column

addSQLAverage

public final void addSQLAverage(SQLExpression<? extends java.lang.Number> field,
                                java.lang.String name)

Add a column AVG to the table output The average is applied in SQL so cannot be combined/merged with other groups or other queries. Use addAverage(SQLExpression, String) unless this is the case.

Parameters:

field - field to sum

name - name for result column

addMinNumber

public final void addMinNumber(SQLExpression<? extends java.lang.Number> field,
                               java.lang.String name)

Add a column min to the table output

Parameters:

field - field to min

name - name for result column

addMinDate

public final void addMinDate(SQLExpression<? extends java.util.Date> field,
                             java.lang.String name)

Add a column min date to table output

Parameters:

field - field to min

name - name for result column

addMaxNumber

public final void addMaxNumber(SQLExpression<? extends java.lang.Number> field,
                               java.lang.String name)

Add a column max to the table output

Parameters:

field - field to max

name - name for result column

addMaxDate

public final void addMaxDate(SQLExpression<? extends java.util.Date> field,
                             java.lang.String name)

Add a column max date to the table output

Parameters:

field - field to max

name - name for result column

addCount

public final void addCount(java.lang.String name)

addSQLCount

public final <T> void addSQLCount(SQLValue<T> expr,
                                  java.lang.String name)

Add a column counting distinct values. We allow SQLValues so we can count references but we are counting the underlying values the count will be too high if multiple values are mapped to the same result so this should not be used if multiple values map to the same key or the results of multiple queries need to be combined

Parameters:

expr -

name -

addCount

public final <T> void addCount(GroupingSQLValue<T> expr,
                               java.lang.String name)
                        throws InvalidKeyException

Add a column counting distinct values.

Type Parameters:

T -

Parameters:

expr -

name -

Throws:

InvalidKeyException

getTarget

public java.lang.String getTarget()

Description copied from interface: ResultMapper

get the target clause of the SQL query. it makes sense to set it here as it has to match what the ResultMapper is expecting

Specified by:

getTarget in interface ResultMapper<O>

Returns:

String

getTargetParameters

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

Description copied from interface: ResultMapper

Add parameters for the target clause to a list.

Specified by:

getTargetParameters in interface ResultMapper<O>

Parameters:

list - to modify

Returns:

modified list of parameter objects

getModifyParameters

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

Description copied from interface: ResultMapper

Add parameters for the GROUP/ORDER clause to a list.

Specified by:

getModifyParameters in interface ResultMapper<O>

Parameters:

list - to modify

Returns:

modified list of parameter objects

addKeyList

protected boolean addKeyList(java.lang.StringBuilder sb)

add group by clauses corresponding to key list

Returns:

true is any added.

Throws:

CannotGroupException

getModify

public final java.lang.String getModify()

Description copied from interface: ResultMapper

provide an override GROUP/ORDER by clause null to use default order from filters

Specified by:

getModify in interface ResultMapper<O>

Returns:

String SQL clause

getRequiredFilter

public SQLFilter getRequiredFilter()

Description copied from interface: ResultMapper

Get an additional Filter required to make the target string work properly. This is usually used to add an additional join.

Specified by:

getRequiredFilter in interface ResultMapper<O>

Returns:

null or SQLFilter