[Tutor] Sorting Data in Databases

[Ken G.]

I have not use the DBMS as I am unaware of them in both languages.   

Lie Ryan wrote:
> Ken G. wrote:
>> The way I use to do it in another programming language (Liberty Basic 
>> in Windows) was:
>>
>> 1. Count number of data entry in database.
>> 2. Dimension or create an array to equal the maximum number of entry.
>> 3. Copy data entry from database into array.
>> 4. Use the SORT command on array, ascending or descending sequence.
>> 5. Copy sorted data from array into database.
>
> In any programming language, that was the wrong algorithm, except for 
> very low-volume purpose. You should ask the DBMS system to sort the 
> database whenever possible instead of doing the sorting yourself.
>
>>  From what I know of Python so far, is it possible to sort the 
>> database as it or do I have to copy data into either a list, tuple or 
>> dictionary and sort there and then, after sorting copy sorted entry 
>> back into the database.
>
> Question time:
> 1. What DBMS are you using?
> 2. What python interface to the DBMS you are using?
> 3. Why do you think you need to sort the database? There is no 
> advantage (that I know of) of having a sorted database. A decent DBMS 
> should determine how best to store the data (it's their problem, not 
> yours). If your DBMS can't do this, you should consider using another 
> DBMS.
> 4. Can't you simply sort the queried data? An SQL-based DBMS should 
> support ORDER BY command to sort the SELECT-ed rows. That should be 
> faster than sorting the whole database. You can sort the returned 
> tuple yourself, but it would be very difficult to beat the DBMS's 
> ORDER BY.
>
>> An outline of what needed to be done will be fine so I can study and 
>> learn the proper way of doing this in Python.  FWIW, I just finished 
>> Alan's tutorial on list, tuple and dictionary.  Whew!!!  Quite 
>> comprehensive.
> As stated, I am unaware of any DBMS in both languages.  In Basic and 
> now in Python, I wrote up a program to input data to the datafile and 
> a program to output the content of the database.  Very primitive and 
> basic.

All of the databases I spoke of are arranged by date and if necessary, 
time.  One contains my blood glucose reading and it is now, the newest 
entry is at the bottom of the database.  I need to arrange it in 
descending order whereas I can print out a report of the last 55 entries 
for my doctor.  Some of the entries in the other databases are not in 
sequenced order and I wish them to be, either ascending or descending 
sequence.  The data are numerical, ranging in the length of 20, 22 and 
44 long with no spaces.

Thank you for letting me look a little further into DBMS.

Ken