Re: Web + Slicing/Paging datas

Hi!

2009.04.23. 9:23 keltezéssel, John R Pierce írta:
> durumdara wrote:
>> Hi!
>>
>> In a mod_py application I wanna write a wrapper that handle all PSQL
>> data view with paging/slicing.
>>
>> ..
>> Inserts all records to a temp table.
>> Check the affected rows (as count).
>> Slicing the records.
>> Fetch the slice records.
>> Destroy temp table.
>
>
> how about KEEPING the data in this slice format, and keeping the count
> somewhere ?  you'd need to update the count and slice info when new
> data gets added, but perhaps thats better than doing it every time you
> want to view a slice?
>
>
This is a complicated thing.
These datas are provided by a query, with some user's conditions.
For example:
Text = Free String Search
Live = This data is living
Category = Some category
SubCategory = Some subcategory
...
etc.

So your way is possible working with this pseudo code:

def Slicing(PageIndex, Conditions):
     # Del recs that have older than 30 minutes
     delsql = "delete from pagingtable where inserted < %s" %
IncWithMinutes(Now, -30)
     ExecSQL(delsql)
     # The Query
     datasql = BuildSQL(Conditions)
     # Have same query in the pool?
     checksql = "select count from pagingtable where sql='%s'" %
SafeEscape(datasql)
     records = ExecSQL(checksql)
     if records:
         # Yes
         count = records[0]['COUNT']
     else:
         # No, we must run a count sql to check
         countsql = BuildSQL(Conditions, Count = 1)
         datarecords = ExecSQL(countsql)
         datarecord = datarecords[0]
         count = datarecord['COUNT']
         # We must insert it to the paging table
         InsertPagingRecord(datasql, count)
     ...
     # Use the count
     ...
     finalsql = BuildSQL(Conditions, WithPaging = PageIndex)
     finalrecords = ExecSQL(finalsql)
     ...

But possible it is too complex and I fear that it cause more pain than I
winning in it... (deadlocks?)...

Thanks for your help:
   dd