uk.ac.ed.epcc.webapp.model.data.expr

Class TableMapper

java.lang.Object

uk.ac.ed.epcc.webapp.AbstractContexed

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

uk.ac.ed.epcc.webapp.model.data.expr.TableMapper

All Implemented Interfaces:

Contexed, ResultMapper<Table>

public class TableMapper
extends SQLGroupMapper<Table>

Creates a Table from a SQL GROUP BY query with a single key. The key expression is used to GROUP the SQL results and a Mapper is used to convert the expression into the table key.

Field Summary

Fields inherited from class uk.ac.ed.epcc.webapp.jdbc.expr.SQLGroupMapper

qualify, use_alias

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

conn

Constructor Summary

Constructors

Constructor and Description
TableMapper(AppContext conn, Mapper m, GroupingSQLValue key, java.lang.String key_name) Make a TableMapper

Method Summary

Modifier and Type	Method and Description
Table	makeDefault() Create a default Object to be returned if no SQL results are generated.
Table	makeObject(java.sql.ResultSet rs) Convert a ResultSet into a domain object.

Methods inherited from class uk.ac.ed.epcc.webapp.jdbc.expr.SQLGroupMapper

addAverage, addClause, addCount, addCount, addKey, addKeyList, addMaxDate, addMaxNumber, addMinDate, addMinNumber, addSQLAverage, addSQLCount, addSum, getModify, getModifyParameters, getRequiredFilter, getTarget, getTargetObject, getTargetParameters, setQualify, setUseAlias

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

Constructor Detail

TableMapper

public TableMapper(AppContext conn,
                   Mapper m,
                   GroupingSQLValue key,
                   java.lang.String key_name)
            throws InvalidKeyException

Make a TableMapper

Parameters:

m - Mapper to convert key expression into table key

key - field/expression to use for key

key_name - name of key expression (can be null if key is a field name)

Throws:

InvalidKeyException

Method Detail

makeObject

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

Description copied from interface: ResultMapper

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

public Table makeDefault()

Description copied from interface: ResultMapper

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