[Gambas-user] Issue 612 in gambas: BUG Cannot browse more of 128 records on tables "No current connection"

[Lewis Balentine]

SQLite (at least the current versions) will always have a row number: 
"/SELECT/rowid  FROM ..."

If the system does not have a unique row number built it (the only thing 
that I use these days is SQLite) then it should be able to be generated 
"on the fly" using a calculated field along with the query. There have 
been many, many DataBases built that do not have key fields defined. One 
particular major accounting system comes to mind that was my curse to 
deal with for many years.  It has been so long since I have encountered 
anything that does not have a row number that I can not recall the SQL 
code to get around it.... I will continue searching :'(

Lewis




On 03/28/2015 01:09 PM, Benoît Minisini wrote:
> Le 28/03/2015 18:58, Lewis Balentine a écrit :
>> I have over three decades of dealing with SQL and I can still not
>> understand how this myth got propagated.
>>
>> There is NO valid SQL reason why a table should be required to have a
>> unique primary key or any predefined key for that matter. One can always
>> use the row number (record number) if such a key is required for one's
>> application.
>>
> The row number does not exist in all database systems (more precisely,
> it is not accessible to the outside), so I can't rely on that feature to
> identify a row uniquely.
>
> Maybe the row id is not standard SQL, if "standard SQL" has any meaning.
>
> Consequently, I need a unique index, usually the primary key.
>
> If you can tell me how to get the row id of a row in MySQL, PostgreSQL
> and SQLite (mabe it has changed since the last time I looked at it), I
> will reconsider my position. :-)
>
> Regards,
>