}
public int update() {
Table table = getSchema().getTableOrView(session, tableName);
session.getUser().checkRight(table, Right.ALL);
table.lock(session, true, true);
switch(type) {
case REFERENTIAL_INTEGRITY_TRUE:
table.setCheckForeignKeyConstraints(session, true, checkExisting);
break;
case REFERENTIAL_INTEGRITY_FALSE: