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Re: How to reference field in record of TStringList

Chris.Cheney wrote:
> Rob Kennedy <me3@privacy.net> wrote in news:6koidsF8vs8aU1
> @mid.individual.net:
>
>> TD wrote:
>>> How do you reference a particular field in a record of a csv file
>>> using TStringList, like the second field in the third string?
>>>
>>> Example - TStringList[3,2] maybe?
>> That obviously doesn't work. You tried it, right?
>>
>> What would that mean for lists of strings? That's what a TStringList
> is,
>> remember. It's not a list of CSV records. It's not a list of anything
>> with any meaning, in fact.
>>
>> TStringList has a way of splitting a single string into several items.
>> Assign the CommaText property, and the string list will be filled with
>> the different fields of the single input. Its method of splitting the
>> string might be OK for your needs. It splits on commas, plus whitespace
>> and any non-printing characters. Quotation marks allow fields to
> contain
>> commas and whitespace.
>>
>> Newer Delphi versions have DelimitedText, so you can split on something
>> other than commas, and even newer versions have the StrictDelimiter
>> property, to say whether bare whitespace will split fields.
>>
>>> Also, I need to be able to search through a csv file to find a
>>> particular record where a particular field in a record matches a
>>> search value; how would I go about doing this?  To explain, say the
>>> string has First Name, Last Name, Age.  How would you find all string
>>> that had the last name Smith?
>> You look at each one, and decide which part represents the last name,
>> and then decide whether it matches Smith.
>>
>
> Why use a TStringList for this task? Surely processing the csv file as a
> descendant of TDataset (e.g. TAdoDataset) would be a _much_ easier, e.g.
>
>   AdoDataset1.ConnectionString := 'Provider=Microsoft.Jet.OLEDB.4.0;Data
> Source=C:\Documents and Settings\chris\My Documents\;Extended
> Properties="text;HDR=Yes;FMTÞlimited";';
>   AdoDataset1.CommandText := 'SELECT * FROM [MyFile.csv] WHERE [Last
> Name]="Smith"'

I never would have considered invoking a Microsoft database library as a
"much simpler" way of processing what is little more than a plain text
file. It's another dependency, and I've never had much confidence in its
reliability, as far as being sure it's installed and configured properly.

--
Rob