I do that with a wee Python script that looks (in part) as follows:
```
sql_import = '''
drop table if exists rawdata;
create virtual table rawdata using vsv(filename="%s",skip=1,schema="create table rawdata(number,date,zone,gender,age,status,state)",columns=7);
insert into cases
select date,
zone,
gender,
age,
status,
count(*) as cnt
from rawdata
group by date, zone, gender, age, status
on conflict (date, zone, gender, age, status)
do update set cnt = max(cnt, excluded.cnt);
'''
for file in reversed(sorted([x for x in os.listdir('.') if x.startswith('data') and x.endswith('.csv')])):
db.executescript(sql_import % (file,))
maxdate = db.execute('select max(date) from rawdata;').fetchone()[0].replace('-', '')
db.execute('drop table if exists rawdata;')
filename = 'data%s.csv' % maxdate
print(file, filename, end=' ')
if file != filename:
if not os.path.exists(filename):
os.rename(file, filename)
print('* RENAMED *')
else:
print('* CANNOT RENAME *')
else:
print(file, 'OK')
```
which looks for all files called "data*.csv" in the current directory and processes them in reverse reverse sort order (assuming the names are dataYYYYMMDD.csv) that would be from oldest to newest) and any file with a badly formed name is renamed to the right name.