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  1. #1
    3 Star Lounger
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    Linking to d-base

    When I link to a d-base table, after I select the table I want to link and click on the "Link" button, Access asks me to Select an index file. I have always just clicked on "Cancel" and the table has been successfully linked, however, I have never understood what it is asking me or why and where I would go to select these index files.

    Be gentle with me and explain as you would to a Martian (ie I don't understand really technical stuff).

  2. #2
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    Re: Linking to d-base

    dbase holds its data in a dbf file with records stored in the order they are created. To view them in some specific order (say customer name) you create and index file (either .ndx or .mdx depending on what version) by using the data file and the index together you can view the records in the required order. You can create several indexes (say order no, date or whatever ) and choose what index to use to suit the occasion. By linking without an index I guess you are simply reading the file in its basic order - ie as the records were created

  3. #3
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    Re: Linking to d-base

    Thanks for your assistance.

    I went into my dbf file using Paradox, created several secondary indexes, yet when I went to link there was still no option. I guess my question is how do I create an index that I can select when requested? At least then I will know why I get this request. Also, you suggested that I am probably getting the original table in the order it was created when I cancel. Sounds reasonable, but I sensed some doubt in your reply. Are you sure?

    If you want the table I am fooling around with, I have attached it to this note. Perhaps you can create an index and send it back so when I link to the dbase file I will have an index when requested.
    Attached Files Attached Files

  4. #4
    Plutonium Lounger
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    Re: Linking to d-base

    Asking you to select an index is built into the dbase ISAM. If you don't select an index, you can look at the data all you want, copy it, query it, etc., but you can't edit it.
    Charlotte

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    Re: Linking to d-base

    sorry but I don't have anything to create dbf indexes and got to admit to knowing a big 0 about paradox.
    There have been a number of packages (natably Clipper and I think early Foxpro) that used the basic dbf format but added their own bells and whistles to the dbase language , Paradox may be another. Or is it just linking to it like Access does and creating its own format index file rather than the dbase style ndx file that the access link is looking for?
    Do you need to update the original dbf in place? If not do you need an index on it anyway?

  6. #6
    Plutonium Lounger
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    Re: Linking to d-base

    Originally, Paradox, FoxPro, and a bunch of others were all dBase clones. Most of the others diverged some time back, but the dbf file format proved so useful that it's hung on even though most of the programs have gone graphical and use their own formats now.

    You only need an index if you want to edit the data in the dbase table, and it has to be a native dbase index. If you just want to look at it or to append it to an Access table, etcl, you don't need an index.
    Charlotte

  7. #7
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    Re: Linking to d-base

    Sorry for being so ignorant, but if I don't ask questions, I guess I'll never know.

    1. What is ISAM?
    2. The problem is that when asked to select an index, there are no options that I see. I guess I am wondering why there are no options and how I could create one in the original dbase database.
    3. I am right in understanding that if you don't select an index, I can not add a record to the linked database? I can only use the information.
    4. The option to select an index does not appear if I am linking to an Excel table. Why not? Does this mean that I can not add a record to the Excel table? (I will try this and find out.)

    Hopefully, you don't mind all of my questions. I am one of those poor souls who has a thirst to know stuff, but has to be fed strained food because if it is too complex, I don't understand it.

    Thanks.

    John

  8. #8
    Plutonium Lounger
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    Re: Linking to d-base

    1. ISAM stands for indexed sequential access method, referring to the type of data access of an application. It is generally used as shorthand to refer to the ISAM database driver for a particular type of database.

    2. That means there are no index files available. In that case, hit cancel and it will skip indexes. You don't have to use indexes with dBase, and not everyone learned how. You would have to use dbase to create the indexes, and it's been 8 years since the last time I used it.

    3. Right.

    4. Excel is not a database (in spite of the way people try to use it) and doesn't have indexes. You should be able to add records and edit linked Excel sheets.

    Don't worry about not understanding it. Everyone has to start somewhere, and I'm just glad I'm not starting out now. The database world (for PCs anyhow) was much simpler when I first entered it, and I still have major learning to do with every new release.
    Charlotte

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