}
public boolean advance() {
posInUnique = null;
if(joinColIt != null && joinColIt.hasNext()) {
JoinColumn joinColumn = joinColIt.next();
colName = joinColumn.getChild().getName();
posInUnique = findPosInIndex(joinColumn.getParent(), joinColumn.getParent().getTable().getPrimaryKey().getIndex()).longValue();
constraintName = it.getName();
} else if(indexColIt != null && indexColIt.hasNext()) {
IndexColumn indexColumn = indexColIt.next();
colName = indexColumn.getColumn().getName();
constraintName = indexColumn.getIndex().getConstraintName() == null ? null : indexColumn.getIndex().getConstraintName().getTableName();