Can the sql_attr_multi uint attribute be set to zero in Sphinx instead of the empty value from from query?

Question

Sphinx

Let's say there is a multi-attribute myattr...

...

source catalogSearch
{

    ...

    sql_query = SELECT ...

    sql_attr_multi = uint myattr from query; SELECT ...

    ...

}

...

If the from query does not contain data to match against sql_query , then Sphinx will write an empty value there. Is it possible to write the explicit value zero (number) instead of this empty value? Maybe there is some kind of value assignment in the form of DEFAULT VALUE or something like that?