Last record of a cursor?
Bob Sneidar
bobsneidar at iotecdigital.com
Fri Sep 17 21:12:11 EDT 2021
Ralph, thanks for the tip. Those handlers were just what I needed. Not sure why I couldn’t find them when I perused the dictionary. Getting daft in my senior years I suppose. I still think it’s inane though, having the first record and last record be 0 when there’s one record. Cannot change it now though.
Sent from my iPhone
> On Sep 17, 2021, at 16:35, Bob Sneidar via use-livecode <use-livecode at lists.runrev.com> wrote:
>
> 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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>
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