diff options
Diffstat (limited to 'lib/sqlalchemy/sql/crud.py')
| -rw-r--r-- | lib/sqlalchemy/sql/crud.py | 66 |
1 files changed, 56 insertions, 10 deletions
diff --git a/lib/sqlalchemy/sql/crud.py b/lib/sqlalchemy/sql/crud.py index 913e4d433..81151a26b 100644 --- a/lib/sqlalchemy/sql/crud.py +++ b/lib/sqlalchemy/sql/crud.py @@ -568,6 +568,7 @@ def _scan_cols( _col_bind_name, implicit_returning, implicit_return_defaults, + postfetch_lastrowid, values, autoincrement_col, insert_null_pk_still_autoincrements, @@ -649,6 +650,7 @@ def _append_param_parameter( _col_bind_name, implicit_returning, implicit_return_defaults, + postfetch_lastrowid, values, autoincrement_col, insert_null_pk_still_autoincrements, @@ -668,11 +670,12 @@ def _append_param_parameter( and c is autoincrement_col ): # support use case for #7998, fetch autoincrement cols - # even if value was given - if implicit_returning: - compiler.implicit_returning.append(c) - elif compiler.dialect.postfetch_lastrowid: + # even if value was given. + + if postfetch_lastrowid: compiler.postfetch_lastrowid = True + elif implicit_returning: + compiler.implicit_returning.append(c) value = _create_bind_param( compiler, @@ -1281,7 +1284,12 @@ def _get_stmt_parameter_tuples_params( def _get_returning_modifiers(compiler, stmt, compile_state, toplevel): + """determines RETURNING strategy, if any, for the statement. + + This is where it's determined what we need to fetch from the + INSERT or UPDATE statement after it's invoked. + """ need_pks = ( toplevel and compile_state.isinsert @@ -1296,19 +1304,58 @@ def _get_returning_modifiers(compiler, stmt, compile_state, toplevel): and not stmt._returning and not compile_state._has_multi_parameters ) + + # check if we have access to simple cursor.lastrowid. we can use that + # after the INSERT if that's all we need. + postfetch_lastrowid = ( + need_pks + and compiler.dialect.postfetch_lastrowid + and stmt.table._autoincrement_column is not None + ) + + # see if we want to add RETURNING to an INSERT in order to get + # primary key columns back. This would be instead of postfetch_lastrowid + # if that's set. implicit_returning = ( + # statement itself can veto it need_pks - and compiler.dialect.implicit_returning - and stmt.table.implicit_returning + # the dialect can veto it if it just doesnt support RETURNING + # with INSERT + and compiler.dialect.insert_returning + # user-defined implicit_returning on Table can veto it + and compile_state._primary_table.implicit_returning + # the compile_state can veto it (SQlite uses this to disable + # RETURNING for an ON CONFLICT insert, as SQLite does not return + # for rows that were updated, which is wrong) + and compile_state._supports_implicit_returning + and ( + # since we support MariaDB and SQLite which also support lastrowid, + # decide if we should use lastrowid or RETURNING. for insert + # that didnt call return_defaults() and has just one set of + # parameters, we can use lastrowid. this is more "traditional" + # and a lot of weird use cases are supported by it. + # SQLite lastrowid times 3x faster than returning, + # Mariadb lastrowid 2x faster than returning + ( + not postfetch_lastrowid + or compiler.dialect.favor_returning_over_lastrowid + ) + or compile_state._has_multi_parameters + or stmt._return_defaults + ) ) + if implicit_returning: + postfetch_lastrowid = False + if compile_state.isinsert: implicit_return_defaults = implicit_returning and stmt._return_defaults elif compile_state.isupdate: implicit_return_defaults = ( - compiler.dialect.implicit_returning - and stmt.table.implicit_returning - and stmt._return_defaults + stmt._return_defaults + and compile_state._primary_table.implicit_returning + and compile_state._supports_implicit_returning + and compiler.dialect.update_returning ) else: # this line is unused, currently we are always @@ -1321,7 +1368,6 @@ def _get_returning_modifiers(compiler, stmt, compile_state, toplevel): else: implicit_return_defaults = set(stmt._return_defaults_columns) - postfetch_lastrowid = need_pks and compiler.dialect.postfetch_lastrowid return ( need_pks, implicit_returning, |