What’s an ISAM? 1

[scottian]

Anyone know what an ISAM is and where I can get a better one?

'Deleting data in a linked table is not supported by this ISAM'

"Children are smarter than any of us. Know how I know that? I don't know one child with a full time job and children."...Bill Hicks

 

[PHV]

Indexed Sequential Access Method

 

[onpnt]

Abbreviation for the saying "Sam I am"?

Sorry couldn't help myself

_{____________ signature below ______________
You are a amateur developer until you realize all your code sucks.
Jeff Atwood}

 

[philhege]

ISAM connections are no longer supported in the latest MS connection tools. You have to use ODBC or OLEDB providers.

Phil Hegedusich
Senior Programmer/Analyst
IIMAK

http://www.iimak.com

-----------
Pity the insomniac dyslexic agnostic. He stays up all night, wondering if there really is a dog.

 

[BobRodes]

ISAM databases are DBMS's that use this method to access data. They include dBase, Paradox, Foxpro, and oh by the way, Access, as well as others such as Excel. The "Joint Engine Technology" or JET driver supports most ISAM DBMS's.

Some underlying ISAM databases don't support some functionality. For example, you can't delete Excel rows by using a SQL DELETE command. That's where you're getting this error.

 

[philhege]

Right, Bob; I was focused on the Foxpro situation and forgot about this.

 

[BobRodes]

Yes, even though I mostly use Access to build mdb files that I then use in VB6 applications, so I'm not very familiar with the Access application, your statement did surprise me a little!

 

[scottian]

Seems daft that you cant delete, but you can update or append Excel rows??????

"Children are smarter than any of us. Know how I know that? I don't know one child with a full time job and children."...Bill Hicks

 

[BobRodes]

Well, it strikes me that the processes of addition and updating are much more similar in Excel to those of other ISAM servers than is the process of deletion. Most processes of deletion mark a record as deleted, and the records aren't actually removed until the database is compacted. Excel can't work that way; it has to do some pretty specialized stuff to delete a row, having do to with rearranging all of the cells in the matrix. As it were, it has to go through a compaction process (one which is quite different from more standard compaction processes, too) each time a row is deleted.

On the other hand, updating a cell is pretty much the same as updating any data location. Appending a row is pretty much analogous to appending a record in a file; in both cases you're simply tacking on another row of data.

So, I suspect it's the requirement of rearranging all of the data on the fly when you delete a row that causes the disconnect between ISAM's delete requirements and Excel's.

Bob

 

[scottian]

Thank you Bob.

Thats a really simple and clear explanation.

"Children are smarter than any of us. Know how I know that? I don't know one child with a full time job and children."...Bill Hicks

 

[BobRodes]

You're very welcome, and thanks for the compliment.