Beginner Question: Detecting empty query result
lazarus / 16-Databases

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dietmar · 2021-10-05 12:12

Hi,

I gather data from a table via

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

Thx,
--Dietmar

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ccrause · 2021-10-05 12:32

Check if IsEmpty of the resulting dataset returns true.

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af0815 · 2021-10-06 04:30

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.

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dietmar · 2021-10-06 17:01

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

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Zvoni · 2021-10-07 07:33

Huh?

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