gh-93925: Improve clarity of sqlite3 commit/rollback, and close docs (#93926)

Co-authored-by: CAM Gerlach <[email protected]>

Author: Erlend Egeberg Aasland

Doc/library/sqlite3.rst

@@ -423,21 +423,20 @@ Connection Objects
 
    .. method:: commit()
 
-      This method commits the current transaction. If you don't call this method,
-      anything you did since the last call to ``commit()`` is not visible from
-      other database connections. If you wonder why you don't see the data you've
-      written to the database, please check you didn't forget to call this method.
+      Commit any pending transaction to the database.
+      If there is no open transaction, this method is a no-op.
 
    .. method:: rollback()
 
-      This method rolls back any changes to the database since the last call to
-      :meth:`commit`.
+      Roll back to the start of any pending transaction.
+      If there is no open transaction, this method is a no-op.
 
    .. method:: close()
 
-      This closes the database connection. Note that this does not automatically
-      call :meth:`commit`. If you just close your database connection without
-      calling :meth:`commit` first, your changes will be lost!
+      Close the database connection.
+      Any pending transaction is not committed implicitly;
+      make sure to :meth:`commit` before closing
+      to avoid losing pending changes.
 
    .. method:: execute(sql[, parameters])
 

Modules/_sqlite/clinic/connection.c.h

@@ -470,12 +470,14 @@ blobopen_impl(pysqlite_Connection *self, const char *table, const char *col,
 /*[clinic input]
 _sqlite3.Connection.close as pysqlite_connection_close
 
-Closes the connection.
+Close the database connection.
+
+Any pending transaction is not committed implicitly.
 [clinic start generated code]*/
 
 static PyObject *
 pysqlite_connection_close_impl(pysqlite_Connection *self)
-/*[clinic end generated code: output=a546a0da212c9b97 input=3d58064bbffaa3d3]*/
+/*[clinic end generated code: output=a546a0da212c9b97 input=b3ed5b74f6fefc06]*/
 {
     if (!pysqlite_check_thread(self)) {
         return NULL;
@@ -522,12 +524,14 @@ int pysqlite_check_connection(pysqlite_Connection* con)
 /*[clinic input]
 _sqlite3.Connection.commit as pysqlite_connection_commit
 
-Commit the current transaction.
+Commit any pending transaction to the database.
+
+If there is no open transaction, this method is a no-op.
 [clinic start generated code]*/
 
 static PyObject *
 pysqlite_connection_commit_impl(pysqlite_Connection *self)
-/*[clinic end generated code: output=3da45579e89407f2 input=39c12c04dda276a8]*/
+/*[clinic end generated code: output=3da45579e89407f2 input=c8793c97c3446065]*/
 {
     if (!pysqlite_check_thread(self) || !pysqlite_check_connection(self)) {
         return NULL;
@@ -557,12 +561,14 @@ pysqlite_connection_commit_impl(pysqlite_Connection *self)
 /*[clinic input]
 _sqlite3.Connection.rollback as pysqlite_connection_rollback
 
-Roll back the current transaction.
+Roll back to the start of any pending transaction.
+
+If there is no open transaction, this method is a no-op.
 [clinic start generated code]*/
 
 static PyObject *
 pysqlite_connection_rollback_impl(pysqlite_Connection *self)
-/*[clinic end generated code: output=b66fa0d43e7ef305 input=12d4e8d068942830]*/
+/*[clinic end generated code: output=b66fa0d43e7ef305 input=7f60a2f1076f16b3]*/
 {
     if (!pysqlite_check_thread(self) || !pysqlite_check_connection(self)) {
         return NULL;