/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.sql;
import java.util.HashSet;
import java.util.Set;

An Oracle-style (theta) join
Author:Jon Lipsky, Gavin King
/** * An Oracle-style (theta) join * * @author Jon Lipsky, Gavin King */
public class OracleJoinFragment extends JoinFragment { private StringBuilder afterFrom = new StringBuilder(); private StringBuilder afterWhere = new StringBuilder(); public void addJoin(String tableName, String alias, String[] fkColumns, String[] pkColumns, JoinType joinType) { addCrossJoin( tableName, alias ); for ( int j = 0; j < fkColumns.length; j++ ) { setHasThetaJoins( true ); afterWhere.append( " and " ) .append( fkColumns[j] ); if ( joinType == JoinType.RIGHT_OUTER_JOIN || joinType == JoinType.FULL_JOIN ) { afterWhere.append( "(+)" ); } afterWhere.append( '=' ) .append( alias ) .append( '.' ) .append( pkColumns[j] ); if ( joinType == JoinType.LEFT_OUTER_JOIN || joinType == JoinType.FULL_JOIN ) { afterWhere.append( "(+)" ); } } } public void addJoin(String tableName, String alias, String[][] fkColumns, String[] pkColumns, JoinType joinType) { addCrossJoin( tableName, alias ); if ( fkColumns.length > 1 ) { afterWhere.append( "(" ); } for ( int i = 0; i < fkColumns.length; i++ ) { afterWhere.append( " and " ); for ( int j = 0; j < fkColumns[i].length; j++ ) { setHasThetaJoins( true ); afterWhere.append( fkColumns[i][j] ); if ( joinType == JoinType.RIGHT_OUTER_JOIN || joinType == JoinType.FULL_JOIN ) { afterWhere.append( "(+)" ); } afterWhere.append( '=' ) .append( alias ) .append( '.' ) .append( pkColumns[j] ); if ( joinType == JoinType.LEFT_OUTER_JOIN || joinType == JoinType.FULL_JOIN ) { afterWhere.append( "(+)" ); } if ( j < fkColumns[i].length - 1 ) { afterWhere.append( " and " ); } } if ( i < fkColumns.length - 1 ) { afterWhere.append( " or " ); } } if ( fkColumns.length > 1 ) { afterWhere.append( ")" ); } } public String toFromFragmentString() { return afterFrom.toString(); } public String toWhereFragmentString() { return afterWhere.toString(); } public void addJoins(String fromFragment, String whereFragment) { afterFrom.append( fromFragment ); afterWhere.append( whereFragment ); } public JoinFragment copy() { OracleJoinFragment copy = new OracleJoinFragment(); copy.afterFrom = new StringBuilder( afterFrom.toString() ); copy.afterWhere = new StringBuilder( afterWhere.toString() ); return copy; } public void addCondition(String alias, String[] columns, String condition) { for ( String column : columns ) { afterWhere.append( " and " ) .append( alias ) .append( '.' ) .append( column ) .append( condition ); } } public void addCrossJoin(String tableName, String alias) { afterFrom.append( ", " ) .append( tableName ) .append( ' ' ) .append( alias ); } public void addCondition(String alias, String[] fkColumns, String[] pkColumns) { throw new UnsupportedOperationException(); } public boolean addCondition(String condition) { return addCondition( afterWhere, condition ); } public void addFromFragmentString(String fromFragmentString) { afterFrom.append( fromFragmentString ); } public void addJoin(String tableName, String alias, String[] fkColumns, String[] pkColumns, JoinType joinType, String on) { //arbitrary on clause ignored!! addJoin( tableName, alias, fkColumns, pkColumns, joinType ); if ( joinType == JoinType.INNER_JOIN ) { addCondition( on ); } else if ( joinType == JoinType.LEFT_OUTER_JOIN ) { addLeftOuterJoinCondition( on ); } else { throw new UnsupportedOperationException( "join type not supported by OracleJoinFragment (use Oracle9iDialect/Oracle10gDialect)" ); } } public void addJoin(String tableName, String alias, String[][] fkColumns, String[] pkColumns, JoinType joinType, String on) { //arbitrary on clause ignored!! addJoin( tableName, alias, fkColumns, pkColumns, joinType ); if ( joinType == JoinType.INNER_JOIN ) { addCondition( on ); } else if ( joinType == JoinType.LEFT_OUTER_JOIN ) { addLeftOuterJoinCondition( on ); } else { throw new UnsupportedOperationException( "join type not supported by OracleJoinFragment (use Oracle9iDialect/Oracle10gDialect)" ); } }
This method is a bit of a hack, and assumes that the column on the "right" side of the join appears on the "left" side of the operator, which is extremely wierd if this was a normal join condition, but is natural for a filter.
/** * This method is a bit of a hack, and assumes * that the column on the "right" side of the * join appears on the "left" side of the * operator, which is extremely wierd if this * was a normal join condition, but is natural * for a filter. */
private void addLeftOuterJoinCondition(String on) { StringBuilder buf = new StringBuilder( on ); for ( int i = 0; i < buf.length(); i++ ) { char character = buf.charAt( i ); final boolean isInsertPoint = OPERATORS.contains( Character.valueOf( character ) ) || ( character == ' ' && buf.length() > i + 3 && "is ".equals( buf.substring( i + 1, i + 4 ) ) ); if ( isInsertPoint ) { buf.insert( i, "(+)" ); i += 3; } } addCondition( buf.toString() ); } private static final Set OPERATORS = new HashSet(); static { OPERATORS.add( Character.valueOf( '=' ) ); OPERATORS.add( Character.valueOf( '<' ) ); OPERATORS.add( Character.valueOf( '>' ) ); } }