/*
* Copyright 2004-2013 H2 Group. Multiple-Licensed under the H2 License,
* Version 1.0, and under the Eclipse Public License, Version 1.0
* (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.lealone.command.ddl;
import org.lealone.command.CommandInterface;
import org.lealone.constant.ErrorCode;
import org.lealone.dbobject.Right;
import org.lealone.dbobject.Schema;
import org.lealone.dbobject.Sequence;
import org.lealone.dbobject.table.Column;
import org.lealone.dbobject.table.Table;
import org.lealone.engine.Database;
import org.lealone.engine.Session;
import org.lealone.expression.Expression;
import org.lealone.message.DbException;
/**
* This class represents the statement
* ALTER SEQUENCE
*/
public class AlterSequence extends SchemaCommand {
private Table table;
private Sequence sequence;
private Expression start;
private Expression increment;
public AlterSequence(Session session, Schema schema) {
super(session, schema);
}
public void setSequence(Sequence sequence) {
this.sequence = sequence;
}
public boolean isTransactional() {
return true;
}
public void setColumn(Column column) {
table = column.getTable();
sequence = column.getSequence();
if (sequence == null) {
throw DbException.get(ErrorCode.SEQUENCE_NOT_FOUND_1, column.getSQL());
}
}
public void setStartWith(Expression start) {
this.start = start;
}
public void setIncrement(Expression increment) {
this.increment = increment;
}
public int update() {
Database db = session.getDatabase();
if (table != null) {
session.getUser().checkRight(table, Right.ALL);
}
if (start != null) {
long startValue = start.optimize(session).getValue(session).getLong();
sequence.setStartValue(startValue);
}
if (increment != null) {
long incrementValue = increment.optimize(session).getValue(session).getLong();
if (incrementValue == 0) {
throw DbException.getInvalidValueException("INCREMENT", 0);
}
sequence.setIncrement(incrementValue);
}
// need to use the system session, so that the update
// can be committed immediately - not committing it
// would keep other transactions from using the sequence
Session sysSession = db.getSystemSession();
synchronized (sysSession) {
db.update(sysSession, sequence);
sysSession.commit(true);
}
return 0;
}
public int getType() {
return CommandInterface.ALTER_SEQUENCE;
}
}