Beginner Question: Detecting empty query result

[dietmar]

Hi,

I gather data from a table via

Code: Pascal  [Select][+][-]

1.   DBHelper.SelectQuery('SELECT * FROM Owner LIMIT 1;');
2.   with DBHelper.SQLQuery do begin
3.     edAuthor.Text := FieldByName('Wiz_Name').AsString + ' (' +
4.       FieldByName('RL_Name').AsString + ')';
5.  

How can I detect whether the query returns an empty result set?

Thx,
--Dietmar

[ccrause]

Check if IsEmpty of the resulting dataset returns true.

[af0815]

Another way is, to check with "Q.BOF AND Q.EOF". If a query is on Begin and End at the same time, the query is empty. This is the same as IsEmpty.

[dietmar]

Ok, and say I am using an UPDATE statement on the table.
If I do this manually, I usually get only a "ok, 1 row affected" or whatever back.
How can I determine here whether the update was successful?

Thx,
--Dietmar

[Zvoni]

Huh?

TSQLQuery inherits from TCustomSQLQuery, and TCustomSQLQuery has a public Function RowsAffected
https://www.freepascal.org/docs-html/fcl/sqldb/tcustomsqlquery.rowsaffected.html