How to sort a multi-column data?

[sbasak]

How to sort a multi-column data? That is, suppose an array contains following columns

LastName
FirstName
Country
City

I want to sort them by LastName, FirstName, Country, City.

What is the way to that? One obvious solution appears to concatenate each field value as a single string and sort then, but is there any better solution? Also, if any field is number, the above said method won't work easily? Any suggestion?

Please don't post database commands (like order by). I like to know how to do it programmatically.

thanks

[Ecniv]

Sounds a little like a recursive loop, but perhaps worse.

One way
First you need to compare on the first field - for the whole array
Then you need to compare the second field ONLY if the first fields match.
Then you need to compare the third field ONLY if the second nad first fields match
...And so on...

Whether you can do this in one loop or several is up to you.

I think (personally) that it has to be several - so the array is sorted properly, but this may hit your processing time.


I'd be interested in your results, if you record times and come up with a way in one loop and a way using several loops to which is faster and produces the correct results. Post up wen you've done it.

Vince

[sbasak]

Thanks for suggestion. Can you tell me how does the databases (Oracle, SQL Server etc.) implement this kind of sort?

[Kunchesm]

I want to sort them by LastName, FirstName, Country, City

if u get that record in ADO recordset 'Rs' then u can sort on multiple fields ..

rs.sort="LastName, FirstName, Country, City"