bpo-41724: Explain when the conversion is not possible with detect_types enabled...

* Explain when the conversion is not possible with detect_types enabled
(cherry picked from commit 09a36cdfb7c22f44df45b44e5561776206bcedfb)

Co-authored-by: sblondon <sblondon@users.noreply.github.com>

diff --git a/Doc/library/sqlite3.rst b/Doc/library/sqlite3.rst
index 314d3a58e2759a85ba1bb3316e8e490f01cbfe23..e493324495890ed89451633624740111e13a3a8f 100644 (file)
--- a/Doc/library/sqlite3.rst
+++ b/Doc/library/sqlite3.rst
@@ -197,7 +197,9 @@ Module functions and constants
 
    *detect_types* defaults to 0 (i. e. off, no type detection), you can set it to
    any combination of :const:`PARSE_DECLTYPES` and :const:`PARSE_COLNAMES` to turn
-   type detection on.
+   type detection on. Due to SQLite behaviour, types can't be detected for generated
+   fields (for example ``max(data)``), even when *detect_types* parameter is set. In
+   such case, the returned type is :class:`str`.
 
    By default, *check_same_thread* is :const:`True` and only the creating thread may
    use the connection. If set :const:`False`, the returned connection may be shared