I would like to group rows of this table according to dates which form the start of SessionID
and for each day, I would like to count how many rows there are for each set of ReqPhone
values. Each set of ReqPhone
values will be defined by the first four digits of ReqPhone
. In other words, I would like to know how many rows there are for ReqPhone
starting with 0925
, 0927
and 0940
, how many rows there are for ReqPhone
starting with 0979
, 0969
and 0955
, etc etc.
I have been trying all kinds of group by
and count
but still haven't arrived at the right query.
Can anybody enlighten me?
Update:
In my country, the government assigns telecoms phone numbers starting with certain digits. Therefore, if you know the starting digits, you know which telecom someone is using. I am trying to count how many messages are sent each day using each telecoms.