org.exolab.castor.jdo.drivers
Class HsqlQueryExpression

java.lang.Object
  org.exolab.castor.jdo.drivers.JDBCQueryExpression
      org.exolab.castor.jdo.drivers.HsqlQueryExpression

All Implemented Interfaces:

QueryExpression

public final class HsqlQueryExpression
extends JDBCQueryExpression

QueryExpression for HypersonicSQL.

This implementation was created mainly to allow the use of multiple outer joins during HSQL query expression creation. The syntax provided by the generic driver does not work with HSQL so this class was needed.

Author:

Santiago Arriaga

Nested Class Summary

(package private) class

HsqlQueryExpression.HsqlAliasInfo This class encapsulates the information of the aliases related to sql outer joins.

Nested classes/interfaces inherited from class org.exolab.castor.jdo.drivers.JDBCQueryExpression

JDBCQueryExpression.Join

Field Summary

Fields inherited from class org.exolab.castor.jdo.drivers.JDBCQueryExpression

_cols, _conds, _distinct, _factory, _joins, _limit, _order, _select, _tables, _where

Fields inherited from interface org.exolab.castor.persist.spi.QueryExpression

OpBetween, OpBetweenAnd, OpEquals, OpGreater, OpGreaterEquals, OpLess, OpLessEquals, OpLike, OpNotEquals, OpNotLike

Constructor Summary

HsqlQueryExpression(PersistenceFactory factory)
Public constructor

Method Summary

void	addColumn(java.lang.String tableName, java.lang.String columnName) Redefinition of JDBCQueryExpression.addColumn() method.
void	addCondition(java.lang.String tableName, java.lang.String columnName, java.lang.String condOp, java.lang.String value) Redefinition of JDBCQueryExpression.addCondition() method.
protected boolean	addWhereClause(java.lang.StringBuffer buffer, HsqlQueryExpression.HsqlAliasInfo aliasInfo, boolean first) This method adds the where clause taking into account possible aliases for columns
java.lang.String	getStatement(boolean lock) This should work for JDBC drivers with a full support of JDBC specification.

Methods inherited from class org.exolab.castor.jdo.drivers.JDBCQueryExpression

addInnerJoin, addInnerJoin, addInnerJoin, addInnerJoin, addLimitClause, addOrderClause, addOuterJoin, addOuterJoin, addOuterJoin, addOuterJoin, addParameter, addSelect, addTable, addTable, addWhereClause, addWhereClause, clone, encodeColumn, getColumnList, getStandardStatement, setDistinct, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

HsqlQueryExpression

public HsqlQueryExpression(PersistenceFactory factory)

Public constructor

Method Detail

addColumn

public final void addColumn(java.lang.String tableName,
                            java.lang.String columnName)

Redefinition of JDBCQueryExpression.addColumn() method. This is needed because aliases are sometimes needed during the creation of HSQL expressions involving multiple outer joins. The original implementation does not allows this.

Specified by:

addColumn in interface QueryExpression

Overrides:

addColumn in class JDBCQueryExpression

Parameters:

tableName - The table name

columnName - The column name

addCondition

public void addCondition(java.lang.String tableName,
                         java.lang.String columnName,
                         java.lang.String condOp,
                         java.lang.String value)

Redefinition of JDBCQueryExpression.addCondition() method. This is needed because aliases are sometimes needed during the creation of HSQL expressions involving multiple outer joins. The original implementation does not allows this.

Specified by:

addCondition in interface QueryExpression

Overrides:

addCondition in class JDBCQueryExpression

Parameters:

tableName - The table name

columnName - The column name

condOp - The conditional operation

value - The conditional value

getStatement

public java.lang.String getStatement(boolean lock)

Description copied from class: JDBCQueryExpression

This should work for JDBC drivers with a full support of JDBC specification.

Specified by:

getStatement in interface QueryExpression

Overrides:

getStatement in class JDBCQueryExpression

Parameters:

lock - True if a write lock is required

Returns:

The SQL statement

addWhereClause

protected boolean addWhereClause(java.lang.StringBuffer buffer,
                                 HsqlQueryExpression.HsqlAliasInfo aliasInfo,
                                 boolean first)

This method adds the where clause taking into account possible aliases for columns

Parameters:

buffer - The buffer being appended

aliasInfo - The information of the aliases to be substituted for some tables