improve query cancellation on control-c

 * sqlexecute.run() no longer returns a tuple, but a Generator of
   SQLResults
 * move sqlexecute.connect() within a try block
 * clarify inner error as e2
 * grammar and spelling in commentary
 * if raising a CommandNotFound(), show the command (this can be part
   of the relevant backtrace)

Due to the first and second bullet, an interrupted query would indeed be
cancelled, but the user would at minimum receive poor feedback, and
the mycli session could also end.

It might also be desirable to tell click not to handle
KeyboardInterrupt.

Author: rolandwalker

changelog.md

@@ -1,3 +1,11 @@
+Upcoming (TBD)
+==============
+
+Bug Fixes
+---------
+* Improve query cancellation on control-c.
+
+
 1.61.0 (2026/03/07)
 ==============
 

mycli/main.py

@@ -1212,14 +1212,13 @@ def one_iteration(text: str | None = None) -> None:
             except KeyboardInterrupt:
                 # get last connection id
                 connection_id_to_kill = sqlexecute.connection_id or 0
-                # some mysql compatible databases may not implemente connection_id()
+                # some mysql-compatible databases may not implement connection_id()
                 if connection_id_to_kill > 0:
                     logger.debug("connection id to kill: %r", connection_id_to_kill)
-                    # Restart connection to the database
-                    sqlexecute.connect()
                     try:
-                        for _preamble, _cur, _headers, status in sqlexecute.run(f"kill {connection_id_to_kill}"):
-                            status_str = str(status).lower()
+                        sqlexecute.connect()
+                        for kill_result in sqlexecute.run(f"kill {connection_id_to_kill}"):
+                            status_str = str(kill_result.status_plain).lower()
                             if status_str.find("ok") > -1:
                                 logger.debug("cancelled query, connection id: %r, sql: %r", connection_id_to_kill, text)
                                 self.echo(f"Cancelled query id: {connection_id_to_kill}", err=True, fg="blue")
@@ -1230,8 +1229,8 @@ def one_iteration(text: str | None = None) -> None:
                                     text,
                                 )
                                 self.echo(f"Failed to confirm query cancellation, id: {connection_id_to_kill}", err=True, fg="red")
-                    except Exception as e:
-                        self.echo(f"Encountered error while cancelling query: {e}", err=True, fg="red")
+                    except Exception as e2:
+                        self.echo(f"Encountered error while cancelling query: {e2}", err=True, fg="red")
                 else:
                     logger.debug("Did not get a connection id, skip cancelling query")
                     self.echo("Did not get a connection id, skip cancelling query", err=True, fg="red")

mycli/packages/special/main.py

@@ -133,7 +133,7 @@ def execute(cur: Cursor, sql: str) -> list[SQLResult]:
     command, verbosity, arg = parse_special_command(sql)
 
     if (command not in COMMANDS) and (command.lower() not in COMMANDS):
-        raise CommandNotFound()
+        raise CommandNotFound(f'Command not found: {command}')
 
     try:
         special_cmd = COMMANDS[command]