uk.ac.ed.epcc.webapp.jdbc.filter

Interface ResultMapper<O>

Type Parameters:

O -

All Known Implementing Classes:

AverageMapMapper, CountDistinctMapMapper, CounterDistinctMapper, CounterMapper, DataObjectFactory.FilterAdapter, DataObjectFactory.ReferencedAdapter, DistinctMapper, ExistsMapper, GeneralMapMapper, LinkManager.JoinLinkMapper, MapMapper, MaximumDateMapMapper, MaximumMapMapper, MinimumDateMapMapper, MinimumMapMapper, RangeSearch.InfoMapper, ReductionMapper, SetMapper, SQLGroupMapper, SumMapMapper, TableMapper, TupleFactory.TupleMapper, ValueResultMapper

public interface ResultMapper<O>

Interface for classes that map ResultSets to Objects Where Filters are used to define which database records are to be selected a ResultMapper defines what data is to retrieved from these records and how it is to be converted into a domain object.

Method Summary

Modifier and Type	Method and Description
default 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.
default 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.
java.util.List<PatternArgument>	getTargetParameters(java.util.List<PatternArgument> list) Add parameters for the target clause to a list.
O	makeDefault() Create a default Object to be returned if no SQL results are generated.
O	makeObject(java.sql.ResultSet rs) Convert a ResultSet into a domain object.
boolean	setQualify(boolean qualify) Request that field names should be qualified with the table name where appropriate.

Method Detail

setQualify

boolean setQualify(boolean qualify)

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.

Parameters:

qualify -

Returns:

previous value of qualify flag

makeObject

O makeObject(java.sql.ResultSet rs)
      throws DataException,
             java.sql.SQLException

Convert a ResultSet into a domain object. The ResultSet should already be positioned at the correct starting Row to start creating the object It is legal for this method to return null to indicate the ResultSet represents an invalid record that should be ignored by the higher levels of the code.

Parameters:

rs - ResultSet or null

Returns:

domain object

Throws:

DataException

java.sql.SQLException

makeDefault

O makeDefault()

Create a default Object to be returned if no SQL results are generated. If there is no obvious default result then return null. Where there is an obvious result (like a sum=0 or an empty Map) this is less error prone than trying to trap null at the calling level. Note that FilterFinder can optionally check for null results and generate exceptions this still fails but makes it easier to find the problem.

Returns:

domain object

getTarget

java.lang.String getTarget()

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

Returns:

String

getTargetParameters

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

Add parameters for the target clause to a list.

Parameters:

list - to modify

Returns:

modified list of parameter objects

getModify

default java.lang.String getModify()

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

Returns:

String SQL clause

getModifyParameters

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

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

Parameters:

list - to modify

Returns:

modified list of parameter objects

getRequiredFilter

default SQLFilter getRequiredFilter()

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

Returns:

null or SQLFilter