selectfragment.java

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//$Id: SelectFragment.java,v 1.4.2.3 2003/11/27 16:10:00 oneovthafew Exp $
package net.sf.hibernate.sql;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;

import net.sf.hibernate.util.StringHelper;

/**
 * A fragment of an SQL <tt>SELECT</tt> clause
 * 
 * @author Gavin King
 */
public class SelectFragment {
	private String suffix;
	private List columns = new ArrayList();
	//private List aliases = new ArrayList();
	private List columnAliases = new ArrayList();

	public SelectFragment setSuffix(String suffix) {
		this.suffix = suffix;
		return this;
	}
	
	public SelectFragment addColumn(String columnName) {
		addColumn(null, columnName);
		return this;
	}

	public SelectFragment addColumns(String[] columnNames) {
		for (int i=0; i<columnNames.length; i++) addColumn( columnNames[i] );
		return this;
	}

	public SelectFragment addColumn(String tableAlias, String columnName) {
		return addColumn(tableAlias, columnName, columnName);
	}

	public SelectFragment addColumn(String tableAlias, String columnName, String columnAlias) {
		columns.add( StringHelper.qualify(tableAlias, columnName) );
		//columns.add(columnName);
		//aliases.add(tableAlias);
		columnAliases.add(columnAlias);
		return this;
	}

	public SelectFragment addColumns(String tableAlias, String[] columnNames) {
		for (int i=0; i<columnNames.length; i++) addColumn( tableAlias, columnNames[i] );
		return this;
	}

	public SelectFragment addColumns(String tableAlias, String[] columnNames, String[] columnAliases) {
		for (int i=0; i<columnNames.length; i++) addColumn( tableAlias, columnNames[i], columnAliases[i] );
		return this;
	}
	
	public SelectFragment addFormulas(String tableAlias, String[] formulas, String[] formulaAliases) {
		for ( int i=0; i<formulas.length; i++ ) addFormula( tableAlias, formulas[i], formulaAliases[i] );
		return this;
	}

	public SelectFragment addFormula(String tableAlias, String formula, String formulaAlias) {
		columns.add( StringHelper.replace(formula, Template.TEMPLATE, tableAlias) );
		columnAliases.add(formulaAlias);
		return this;
	}

	public String toFragmentString() {
		StringBuffer buf = new StringBuffer( columns.size() * 10 );
		Iterator iter = columns.iterator();
		//Iterator aliasIter = aliases.iterator();
		Iterator columnAliasIter = columnAliases.iterator();
		HashMap columnsUnique = new HashMap(); 
		while ( iter.hasNext() ) {
			String column = (String) iter.next();
			//String alias = (String) aliasIter.next();
			String columnAlias = (String) columnAliasIter.next();
			String qualifiedColumn = column; //alias==null ? column : alias + StringHelper.DOT + column;
			Object otherAlias = columnsUnique.put(qualifiedColumn, columnAlias);
			//if (otherAlias!=null) {
				//TODO: eventually put this back in, once we think all is fixed
				/*if ( !( columnAlias.equals(otherAlias) ) ) {
					throw new AssertionFailure("bug in Hibernate SQL alias generation");
				}*/
			if ( columnAlias.equals(otherAlias) ) {
			}
			else {
				buf.append(StringHelper.COMMA_SPACE)
					.append(qualifiedColumn)
					.append(" as ")
					.append( new Alias(suffix).toAliasString(columnAlias) );
			}
		}
		return buf.toString();
	}
}