The V17 dbisql GUI can silently partially truncate the SELECT result set when a string right truncation is encountered in the SELECT list.

Update: A simple reproducible...

Using ISQL Version 17.0.10 build 6089, with Data - Show Results in Scrollable Table this works as expected:

SET OPTION on_error = 'Prompt';
SELECT CAST ( STRING ( row_num, ' ', '1234567890' ) AS VARCHAR ( 12 ) ) 
  FROM rowgenerator
 WHERE row_num <= 10
 ORDER BY row_num;

There was an error reading the results of the SQL statement.
The displayed results may be incorrect or incomplete.
Right truncation of string data
SQLCODE=-638, ODBC 3 State="22001"
Line 2, column 1

With Data - Show Results as Text it displays a partial result set with no error message.

SET OPTION on_error = 'Prompt';
SELECT CAST ( STRING ( row_num, ' ', '1234567890' ) AS VARCHAR ( 12 ) ) 
  FROM rowgenerator
 WHERE row_num <= 10
 ORDER BY row_num;

STRING(rowgenerator.row_num,' ','1234567890') 
--------------------------------------------- 
1 1234567890                                  
2 1234567890                                  
3 1234567890                                  
4 1234567890                                  
5 1234567890                                  
6 1234567890                                  
7 1234567890                                  
8 1234567890                                  
(8 rows)

...end Update

Is this a bug, or an enhancement? (I can try to build a simpler reproducible if anyone is interested).

A bad SELECT is shown below; it contains CAST ( ... VARCHAR ( 24 ) ) which should have length 25.

The string_rtruncation option is ON.

The V16 copy of the GUI dbisql.com connected to a 17.0.9.4882 database on the 17.0.10.6089 engine does not return any rows, and correctly reports this exception:

There was an error reading the results of the SQL statement.
The displayed results may be incorrect or incomplete.

Cursor not in a valid state
SQLCODE=-853, ODBC 3 State="24000"

Right truncation of string data
SQLCODE=-638, ODBC 3 State="22001"
Line 1, column 1
(Continuing after error)

The V17 dbisql.com returns 7 rows (there should be 173), and it does not report ANY error.

Active At                       ID Alert                    Status                                     
----------------------- ---------- ------------------------ ------------------------------------------ 
2020-12-24 01:34:50.181          1 28 Long transaction      Clear/Cancelled at 2020-12-24 01:44:25.623 
2020-12-24 00:09:43.433          1 21 Temp space usage      Clear/Cancelled at 2020-12-24 00:15:20.593 
2020-12-24 00:09:05.052          1 22 Conn temp space usage Clear/Cancelled at 2020-12-24 00:15:20.593 
2020-12-23 19:45:41.472          1 28 Long transaction      Clear/Cancelled at 2020-12-23 19:58:44.708 
2020-12-23 07:08:42.696          1 28 Long transaction      Clear/Cancelled at 2020-12-23 17:41:34.735 
2020-12-23 01:34:42.682          1 28 Long transaction      Clear/Cancelled at 2020-12-23 01:44:07.579 
2020-12-23 00:08:23.545          1 21 Temp space usage      Clear/Cancelled at 2020-12-23 00:17:32.238 
(7 rows)

Here is the bad query...

SELECT DATEFORMAT ( alert.alert_in_effect_at, 'yyyy-mm-dd hh:nn:ss.sss' ) AS "Active At",
       sampling_options.sampling_id                                       AS "ID",
       CAST ( STRING ( alert.alert_number,  
              ' ',  
              alert_title.alert_title ) AS VARCHAR ( 24 ) )               AS "Alert",
       IF alert.alert_is_clear_or_cancelled = 'N'
          THEN 'Still Active'
          ELSE STRING ( 
             'Clear/Cancelled at ',
             DATEFORMAT ( COALESCE ( all_clear.alert_all_clear_at,  
                          alert_cancelled.alert_all_clear_at ), 
                         'yyyy-mm-dd hh:nn:ss.sss' ) )
       END IF                                                             AS "Status" 
  FROM sampling_options
       INNER JOIN alert
          ON alert.sampling_id = sampling_options.sampling_id
       LEFT OUTER JOIN all_clear
          ON all_clear.sampling_id        = sampling_options.sampling_id
         AND all_clear.alert_number       = alert.alert_number
         AND all_clear.alert_in_effect_at = alert.alert_in_effect_at
       LEFT OUTER JOIN alert_cancelled
          ON alert_cancelled.sampling_id        = sampling_options.sampling_id
         AND alert_cancelled.alert_number       = alert.alert_number
         AND alert_cancelled.alert_in_effect_at = alert.alert_in_effect_at
      INNER JOIN alert_title
          ON alert.alert_number     = alert_title.alert_number
 WHERE alert.alert_number <> 1
 ORDER BY "ID",
       "Active At" DESC,
       "Alert";