hello,

with out getting too technical, as a programmer not that difficult to
do..............

*memo fields* are often references as BLOB fields
an acronym for Binary Large OBjects

dBase, which MI is an obfuscated form of, makes use of these
along with M$ Excess and others.

Internally the field will be a unique temporary filename, possibly a
name you can recognize the disk, and most it is compeletly unrecognizable
and holds pointers and length values into a single file that
holds all the table BLOB data [if you lucky the extension might be *.BLB].

Why BLOB's came about was to get around the 254 character limit in fields,
which is based on one byte [0 to 255] hold the actual length.

But over time M$ and others have been able to use it to store
true binary data like picture formats [bmp,jpg,gif....] and
now just about anything you want to put there.

Thinking about it, MI's *.MAP file, could be considered a BLOB
as each record contains a whole heap if information, the
most being for poly-line/regions, with x1/y1....x#/y#, line style, color,
etc
that is linked from the data record.

So if your table has a MEMO/BLOB and you tell MI, in it's lesser
intellectual capacity, to write to that table..........get the idea


Trey Pattillo
[EMAIL PROTECTED]
www.wap3.com
-97.66532W 27.79902N
----- Original Message -----
From: "Bill & Lorraine Donaldson" <[EMAIL PROTECTED]>
To: "Mapinfo-L" <[EMAIL PROTECTED]>
Sent: Friday, January 11, 2002 06:29
Subject: MI-L Alter Table and memo fields


>
>
>
> In the MapBasic 6.5 Reference Guide (pg. 52) the Alter Table statement
makes
> the following reference to memo fields:
>
> "If a MapBasic application issues an Alter Table statement affecting a
table
> which has memo fields, the memo fields will be lost. No warning will be
> displayed."
>
> What exactly are these "memo fields" that are mentioned?
>
> Thanks in advance for any enlightment that is provided!
>
> Bill
>
>
>
> _______________________________________________________________________
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