使用regexp。

Select sum(case when fsid   is not null then 1 else 0 end) as count_fsid
    ,  sum(case when userid is not null then 1 else 0 end) as count_userid
    from
        (Select regexp_extract(my_string, '.*fsid=(//d*)&.*')   as fsid
              , regexp_extract(my_string, '.*userid=(//d*)&.*') as userid
        from my table
        ) a ;