'<tbl>.index_primary_put' not working

[Michael Nesseler]

Hi!
I wrote an Patient Administration-Application for for an Animal Hospital.
Now I have the following problem:
I would like to change the Primary index of a other Table ("patient")
via 2 Buttons:
Xbasic on Button 1:
t = table.open("patienten")
i = t.index_primary_put("Abteilung_Haut")
t.close()
Xbasic on Button 2:
t = table.open("patienten")
i = t.index_primary_put("Abteilung_Knochen")
t.close()
Readout of Index returns nothing:
t = table.open("patienten")
iget = t.index_primary_get()
name = iget.name_get()
trace.WriteLn("Primary index = " + name)
t.close()
or
t = table.open("C:\OP\Anwendung\patienten.dbf")
iget = t.index_primary_get()
name = iget.name_get()
trace.WriteLn("Primary index = " + name)
t.close()
Where is my error? Please, can somebody help me?
Many thanks
Michael


ENGLISH:
Ich habe eine Anwendung zur Patientenverwaltung f&uuml;r eine Tierklinik geschrieben.
Nun habe ich folgendes Problem:
Ich m&ouml;chte mittels 2 Buttons den Primary Index eines fremden Tables ("patienten") &auml;ndern:
Xbasic auf Button 1:
t = table.open("patienten")
i = t.index_primary_put("Abteilung_Haut")
t.close()
Xbasic auf Button 2:
t = table.open("patienten")
i = t.index_primary_put("Abteilung_Knochen")
t.close()
Noch nicht mal das Auslesen des aktuellen Index funktioniert:
t = table.open("patienten")
iget = t.index_primary_get()
name = iget.name_get()
trace.WriteLn("Primary index = " + name)
t.close()
oder
t = table.open("C:\OP\Anwendung\patienten.dbf")
iget = t.index_primary_get()
name = iget.name_get()
trace.WriteLn("Primary index = " + name)
t.close()

Was mache ich falsch? W�re f�r Hilfe dankbar
Vielen Dank schon mal...
Michael

[Tom Cone Jr]

RE: '&lt;tbl&gt;.index_primary_put' not working

Michael,

Only one index can be "primary" for a table at any one time. When you need to use a particular index for a table make it primary prior to fetching or navigating within the table. Do not assume that the last process which used the table left the desired index in place. Set it primary each time you want to use the table.

I've always assumed the default index for any table is either the first indextag defined for the table, or the natural order of the records (record number sequence). However, there's never been a reason to study this. I choose not to ever use the "default" index, preferring instead to guarantee that the desired index is primary each and every time I use a table. (By explicitly setting that index primary for each instance of the table that I open.)

I was able to reproduce the behavior you're seeing. However, I do not know if it's a problem with "index_pointer".name_get() or with our understanding of what it means to be "primary". It has never ever bothered me, since I always explicitly set the desired index each time I open a table. My own practice is to never ever assume that a previous process left the desired index as primary.

-- tom

[Michael Nesseler]

RE: '&lt;tbl&gt;.index_primary_put' not working

Hi Tom!

Thanks for your comment! This Project is my first Database Application (and my English is poor too).

I only need one (Primary) Index at a time: The Table must be filtered either by Field Value "Haut" OR "Knochen", nothing more.

That's my Indexes on the Table:

Index Name : Order Exp : Filter Exp : Direction : Include
---------------------------------------------------------
Abteilung_Haut : NAME : ABTEILUNG="Haut" : Descending : All
Abteilung_Knochen : NAME : ABTEILUNG="Knochen" : Descending : All

But how can i do that?
I have read the A5 Manuals and i think i have understood the Sense of Indexing, but perhaps some basics are still missing to me.

Thanks
Michael

[Stan Mathews]

RE: '&lt;tbl&gt;.index_primary_put' not working

What Tom is trying to tell you is

t = table.open("patienten") 'opens the table
i = t.index_primary_put("Abteilung_Haut") 'sets the prinary index for the duration of the script
t.close() 'closes the table, the index is no longer primary

Try

t = table.open("patienten")
i = t.index_primary_put("Abteilung_Haut")
iget = t.index_primary_get()
name = iget.name_get()
trace.WriteLn("Primary index = " + name)
t.close()

In usage you would do this in a script

t = table.open("patienten")
i = t.index_primary_put("Abteilung_Haut")
'statements here to process records
'in "Abteilung_Haut" order
t.close()

When the script finishes, the table is no longer in "Abteilung_Haut" order.

[martinwcole]

RE: '&lt;tbl&gt;.index_primary_put' not working

since you want to do this from a button, if you are doing this from a form based on a set and you are referencing the parent table for the form, or if not based on a set, the table the form is based on, you would say

parentform.index_set("indexname")

[CALocklin]

RE: '&lt;tbl&gt;.index_primary_put' not working

Or, better yet, use .Index_SetVerify() in case the index is missing.

This is especially important in this case due to the length of the index names and the way they are defined - Abteilung_Knochen and Abteilung_Haut. Since the first 10 characters are "Abteilung_" and a truncated index name would end up being 10 characters, if both index names did happen to get truncated and you tried to open the "Abteilung_Knochen" index, you would probably get the "Abteilung_Haut" index without warning instead because it would find the first "Abteilung_" index. If one of the indexes completely dissappeared, it would find and use the other index without warning. If both indexes disappeared, I'm not sure what it would use but it certainly wouldn't use the correct index and it wouldn't give you a warning either.

Note the number of times "without warning" appears above!

Since there isn't a built-in table method like .index_primary_putVerify(""), I even created my own method so I can always be sure the correct index is available. It's not an issue 99.99% of the time but that other .01% could create real problems.

Cal Locklin
www.aimsdc.net

[Michael Nesseler]

RE: '&lt;tbl&gt;.index_primary_put' not working

Ok, I have tried and understood. Thanks for this Lesson...

Table Indexing appears to be the wrong way to solve my problem.

What's the easiest way for filtering a table, so that i can access this table from several forms without filtering on each individual form? (that's what i mean with 'global filtering')

Is that possible in principle?

Thanks
Michael

[martinwcole]

RE: '&lt;tbl&gt;.index_primary_put' not working

Excellent advice - I missed noticing the the first 10 characters were not unique - but I cannot find anywhere the form method you mentioned [.Index_SetVerify().] where is it?

[martinwcole]

RE: '&lt;tbl&gt;.index_primary_put' not working

if the table is always a parent or the only table the form is based on, you can create an index, and have the filter in the index, and set the form's main index to that respective index.