/*
 * 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.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.hibernate.LockMode;
import org.hibernate.LockOptions;
import org.hibernate.dialect.Dialect;

An SQL SELECT statement with no table joins
Author:Gavin King
/** * An SQL <tt>SELECT</tt> statement with no table joins * * @author Gavin King */
public class SimpleSelect { public SimpleSelect(Dialect dialect) { this.dialect = dialect; } //private static final Alias DEFAULT_ALIAS = new Alias(10, null); private String tableName; private String orderBy; private Dialect dialect; private LockOptions lockOptions = new LockOptions( LockMode.READ ); private String comment; private List<String> columns = new ArrayList<String>(); private Map<String, String> aliases = new HashMap<String, String>(); private List<String> whereTokens = new ArrayList<String>(); public SimpleSelect addColumns(String[] columnNames, String[] columnAliases) { for ( int i = 0; i < columnNames.length; i++ ) { if ( columnNames[i] != null ) { addColumn( columnNames[i], columnAliases[i] ); } } return this; } public SimpleSelect addColumns(String[] columns, String[] aliases, boolean[] ignore) { for ( int i = 0; i < ignore.length; i++ ) { if ( !ignore[i] && columns[i] != null ) { addColumn( columns[i], aliases[i] ); } } return this; } public SimpleSelect addColumns(String[] columnNames) { for ( String columnName : columnNames ) { if ( columnName != null ) { addColumn( columnName ); } } return this; } public SimpleSelect addColumn(String columnName) { columns.add( columnName ); //aliases.put( columnName, DEFAULT_ALIAS.toAliasString(columnName) ); return this; } public SimpleSelect addColumn(String columnName, String alias) { columns.add( columnName ); aliases.put( columnName, alias ); return this; } public SimpleSelect setTableName(String tableName) { this.tableName = tableName; return this; } public SimpleSelect setLockOptions(LockOptions lockOptions) { LockOptions.copy( lockOptions, this.lockOptions ); return this; } public SimpleSelect setLockMode(LockMode lockMode) { this.lockOptions.setLockMode( lockMode ); return this; } public SimpleSelect addWhereToken(String token) { if (token != null ) { if (!whereTokens.isEmpty()) { and(); } whereTokens.add( token ); } return this; } private void and() { if ( whereTokens.size() > 0 ) { whereTokens.add( "and" ); } } public SimpleSelect addCondition(String lhs, String op, String rhs) { and(); whereTokens.add( lhs + ' ' + op + ' ' + rhs ); return this; } public SimpleSelect addCondition(String lhs, String condition) { and(); whereTokens.add( lhs + ' ' + condition ); return this; } public SimpleSelect addCondition(String[] lhs, String op, String[] rhs) { for ( int i = 0; i < lhs.length; i++ ) { addCondition( lhs[i], op, rhs[i] ); } return this; } public SimpleSelect addCondition(String[] lhs, String condition) { for ( String lh : lhs ) { if ( lh != null ) { addCondition( lh, condition ); } } return this; } public String toStatementString() { StringBuilder buf = new StringBuilder( columns.size() * 10 + tableName.length() + whereTokens.size() * 10 + 10 ); if ( comment != null ) { buf.append( "/* " ).append( comment ).append( " */ " ); } buf.append( "select " ); Set<String> uniqueColumns = new HashSet<String>(); Iterator<String> iter = columns.iterator(); boolean appendComma = false; while ( iter.hasNext() ) { String col = iter.next(); String alias = aliases.get( col ); if ( uniqueColumns.add( alias == null ? col : alias ) ) { if ( appendComma ) { buf.append( ", " ); } buf.append( col ); if ( alias != null && !alias.equals( col ) ) { buf.append( " as " ) .append( alias ); } appendComma = true; } } buf.append( " from " ) .append( dialect.appendLockHint( lockOptions, tableName ) ); if ( whereTokens.size() > 0 ) { buf.append( " where " ) .append( toWhereClause() ); } if ( orderBy != null ) { buf.append( orderBy ); } if ( lockOptions != null ) { buf = new StringBuilder(dialect.applyLocksToSql( buf.toString(), lockOptions, null ) ); } return dialect.transformSelectString( buf.toString() ); } public String toWhereClause() { StringBuilder buf = new StringBuilder( whereTokens.size() * 5 ); Iterator<String> iter = whereTokens.iterator(); while ( iter.hasNext() ) { buf.append( iter.next() ); if ( iter.hasNext() ) { buf.append( ' ' ); } } return buf.toString(); } public SimpleSelect setOrderBy(String orderBy) { this.orderBy = orderBy; return this; } public SimpleSelect setComment(String comment) { this.comment = comment; return this; } }