Index Memo Fields ?

[TimStone]

Is it possible to index the first part of a memo field ? I'd like to build an index based on the first 60 characters of the memo, regardless of how long it is actually.

Tim

[nageswaragunupudi]

Yes
Please use PADR() instead of LEFT()
INDEX ON PADR( <field>, 60 ) TAG ...

[TimStone]

Generates error:

Error description: Error ADSCDX/3009 Error 3009: Unsupported data type in function parameter in index key expression.

[hmpaquito]

try so:

Code: Select all  Expand view

INDEX ON Left( <field>+ Space(60), 60 ) TAG ...

[nageswaragunupudi]

I tested with this code and it worked for me

Code: Select all  Expand view

 
function test()

   FIELD CODE

  USE C:\FWH\SAMPLES\PROCESS NEW EXCLUSIVE VIA "DBFCDX"
   INDEX ON PADR(CODE,20) TAG CODEX
   CLOSE DATA

   USE C:\FWH\SAMPLES\PROCESS
   SET ORDER TO TAG CODEX
   ? ORDKEY()  // --> "PADR(CODE,20)"
   XBROWSER DBSTRUCT()
   return nil
 

[TimStone]

I'm using Advantage Database Server ... won't work with it. The functions are not supported.

[James Bott]

Hi Tim,

Its a disk space waste, but you could post the first 60 characters of the memo field to another field every time you save the record, then index on that. Since you are using database objects, you can do this automatically in the save method.

Code: Select all  Expand view

Class TCustomer from TData
   Method Save()
Endclass

Method Save() Class TCustomer
   ::notes60= left( ::notes, 60 )
Return  super:save()
 

Now whenever you save a customer object, both fields are updated automatically. You just need to index on the notes60 field.


Regards,
James

[nageswaragunupudi]

I'm using Advantage Database Server ... won't work with it. The functions are not supported.

On ADS, this might work

INDEX ON Left( <field>+ Space(60), 60 ) TAG ...

[James Bott]

Nages,

Well, if that works it would be a lot simpler than my suggestion.

James

[TimStone]

James, for this task it might be easier to simply add a field to a database ... which would accomplish what the client requested ... but I just don't want to a db update right now. The field would actually be the best solution ...

Nages, I had tried that method and though it doesn't error out, it also does not build an index. I can set this aside for now and deal with it another way later.

Thanks.

[James Bott]

Tim,

James, for this task it might be easier to simply add a field to a database

I'm sorry, I didn't make that clear, you would need to add a field, then you modify the Save() method so it automatically saves the first 60 characters of the memo field to the new 60 character length string field. This way it the new field is always up to date.

I'm not sure what indexing will get you? I can see searching this though. Indexing and seeking would only get you the first word, right? Maybe I am missing something.

James