CRC calculation per record possible? (Continued from threa..

Dear Listeners,

On 6 Nov. 2008 I had asked the group whether somebody knew a solution to
check records which contain a field with a long string (160 or even 260
bytes) for duplicate entries. I need(ed) to find even the slightest
difference amongst bank account records downloaded from a telebanking site.
There were several contributions (MD5, Plugins) - thanks for that input so
far.

A few days ago I started tinkering on that issue again and found another way
to tackle it - it turned out to be surprisingly simple!

Using plain FMP 6 I did the following:

--

Create 2 global fields, type text:

g.comparison.1

g.comparison.2

--



Create a text field:

t.duplicate.marker

--

Create a calc field:

c.compare.comparison.1.with.comparison.2

with the following formula:

Case(

Left(g.comparison.1;20)
=
Left(g. comparison.2;20)

and

Middle(g. comparison.1;21;20)
=

Middle(g. comparison.2;21;20)

and

[and so forth...]

Middle(g. comparison.1;241;20)
=
Middle(g. comparison.2;241;20)

;
"Duplicate!";

""
)

--

Create a script:

Sort [Restore, No dialog]

Replace Contents [No dialog, "t.duplicate.marker", """"]

Go to Record/Request/Page [First]

Loop

Exit Loop If ["Status(CurrentRecordNumber)=Status(CurrentFoundCount) "]

Set Field ["g.comparison.1", "Substitute(--here a text concatenation of all
fields to be compared--;" ";"")"]

#Comment: Substitute is used to shorten the string as much as possible.

Go to Record/Request/Page [Next]

Set Field ["g.comparison.2", "Substitute(--here a text concatenation of all
fields to be compared--;" ";"")"]

If ["c.compare.comparison.1.with.comparison.2="Duplicate!""]

Set Field ["t.duplicate.marker", ""Attention! Duplicate!""]

End If

End Loop

--

Even with a field length of 260 (normally the maximum in FMP 6 would be 60)
the comparison works flawlessly and quite fast - approx. 900 records/second
on a 2.4 GHz Win XP machine.

--
Met vriendelijke groet / Mit freundlichen Gruessen / With kind regards
Christoph Bouthillier
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