The Stop button is used to cancel a command.
A Stop operation stops current processing and prompts for the next command. If a command file was being processed, you are prompted for an action to take: Stop command file, Continue, or Exit dbisqlc. These actions can be controlled with the dbisql ON_ERROR option (see Chapter 2, “Database Options” in the Sybase IQ Reference Manual).
When a command is canceled, one of three different errors will be reported depending upon when the end is detected.
If the cancellation is detected when dbisqlc is processing the request (as opposed to the database engine), then the following message is displayed:
dbisql command terminated by user
dbisqlc stops processing immediately and the database transaction is left alone.
If the cancellation is detected while the database engine is processing a data definition command (CREATE, DROP, ALTER, etc.), the following message appears:
Terminated by user -- transaction rolled back
Since data definition commands all perform a COMMIT automatically before the command starts, the effect of the ROLLBACK is to just cancel the current command.
This message also occurs when the database engine is running in bulk operations mode executing a command that modifies the database (INSERT and DELETE). In this case, ROLLBACK cancels not only the current command, but everything that has been done since the last COMMIT or ROLLBACK. In some cases, it may take a considerable amount of time for the database engine to perform the automatic ROLLBACK.
If the cancel is detected by the database engine while processing a standard data manipulation command (SELECT, INSERT, DELETE, etc.) and the engine is not running in bulk operations mode, then the following message is displayed.
Statement interrupted by user.
The effects of the current command are undone, but the rest of the transaction is left intact.
