Last record of a cursor?
Bob Sneidar
bobsneidar at iotecdigital.com
Fri Sep 17 19:34:05 EDT 2021
Oh sorry, I posted this just before Ralph replied. Thanks Ralph I will try your suggestions.
Bob S
> On Sep 17, 2021, at 16:32 , Bob Sneidar <bobsneidar at iotecdigital.com> wrote:
>
> Okay something is not right with the API! First, my query in my script is set to:
>
> SELECT * from files where siteid = '1659'
>
> If I run this in mySQLWorkbench, I get one record, so I know the query works. Also, I know the cursor contains records, because as I step through the loops which get the column values, I can see the vlaues in the variables populate when I use:
>
> put revDatabaseColumnNumbered(pCursorID, i) into tColumnValue
>
> Here is the rub though. The first record of a cursor is 0. ZERO!!! And if there is only one record, guess what the LAST record is??? ZERO!!!!!
>
> Does that make the least bit of sense to ANYONE??? There is no call that I can find to get the number of records of a cursor! Therefore I can NEVER TELL if a cursor contains any records.
>
> If anyone has a method for doing so, your help will be very much appreciated.
>
> Bob S
>
>> On Sep 17, 2021, at 16:04 , Bob Sneidar via use-livecode <use-livecode at lists.runrev.com> wrote:
>>
>> Hi all.
>>
>> I am trying to discern between when I have an empty cursor, and when I have reached the last record of a cursor.
>>
>> I have noticed that if I query a database that returns no results, I still get a cursor ID, so I cannot test for a cursor ID. So after my loop to convert a cursor to an array, I check to see if I am on the last record by using put revCurrentRecord(pCursorID) into tLastRecord, then testing to see if it returns 0, which it will if the cursor is empty.
>>
>> But it seems that if I am already on the last record of the cursor, then I use revMoveToNextRecord pCursorID, revCurrentRecord ALSO RETURNS 0! So now I am left without a way to tell if the cursor is empty, or if otherwise, I have reached the last record.
>>
>> How is this done?? Normally I use sqlYoga so these things are spared me, but in this instance I am using the native API calls.
>>
>> Bob S
>>
>>
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