Missing data from Visits Over Time graph

I have been uploading data from access files into the database using the following process.

for HOUR in 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23; do python /var/www/piwik/misc/log-analytics/import_logs.py --enable-http-errors --enable-http-errors --enable-http-redirects --exclude-path-from=/home/piwik/excludepaths.txt --url=https://stats.globalcollect.com/piwik/ --idsite=8 /tmp/parselogs.13.07/access_na.gcsip.com20130713${HOUR}; sleep 10; done
for HOUR in 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23; do python /var/www/piwik/misc/log-analytics/import_logs.py --enable-http-errors --enable-http-errors --enable-http-redirects --exclude-path-from=/home/piwik/excludepaths.txt --url=https://stats.globalcollect.com/piwik/ --idsite=8 /tmp/parselogs.14.07/access_na.gcsip.com20130714${HOUR}; sleep 10; done
for HOUR in 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23; do python /var/www/piwik/misc/log-analytics/import_logs.py --enable-http-errors --enable-http-errors --enable-http-redirects --exclude-path-from=/home/piwik/excludepaths.txt --url=https://stats.globalcollect.com/piwik/ --idsite=8 /tmp/parselogs.15.07/access_na.gcsip.com20130715${HOUR}; sleep 10; done

This has worked for me in the past and for some reason while running the script, I see no errors and I see that data is being read into the database, but when I look at the graph I see no data.

  1. How can I run a query on the database to see if the data has in fact been inserted?
  2. Why would the data is present not be visible on the graph?
  3. How can I flush the database so that I could try reinserting the data?

Any help and advice would be very much appreciated.

Thanks
Lawrence