On 5/25/18 12:16, Tom Lane wrote:
> I notice there are still several places in pl_exec.c like this:
>
> case SPI_ERROR_TRANSACTION:
> ereport(ERROR,
> (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
> errmsg("cannot begin/end transactions in PL/pgSQL"),
> errhint("Use a BEGIN block with an EXCEPTION clause
> instead.")));
> break;
>
> At best, the wording of these error messages is now obsolete. I'm not
> sure if we expect them to be reachable at all. If they should be
> can't-happen cases, I'd suggest just deleting them and letting control
> fall to the generic default: cases in each switch. If they are reachable,
> the messages need work.
There are three occurrences:
The occurrence in exec_prepare_plan() could never be reached AFAICT,
because SPI_prepare_params() does not produce those SPI_prepare_params()
error values in the first place. So remove them altogether.
The occurrence in exec_stmt_execsql() can be reached by running for
example SAVEPOINT, or any other TransactionStmt other than COMMIT and
ROLLBACK, which are intercepted by PL/pgSQL. So we still need an error
message there. Unfortunately, we don't know which TransactionStmt
caused the error, so the error has to be pretty generic.
The occurrence in exec_stmt_dynexecute() can be reached using something
like EXECUTE 'COMMIT', which is not supported/not implemented. Hence a
tweaked error message there as well.
Possible patch attached.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
From 94a5dc7ad0b3a9d1a500a3220f7cbbc9af7c9465 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Thu, 31 May 2018 07:51:02 -0400
Subject: [PATCH] Reword SPI_ERROR_TRANSACTION errors in PL/pgSQL
The previous message for SPI_ERROR_TRANSACTION claimed "cannot begin/end
transactions in PL/pgSQL", but that is no longer true. Nevertheless,
the error can still happen, so reword the messages. The error cases in
exec_prepare_plan() could never happen, so remove them.
---
src/pl/plpgsql/src/pl_exec.c | 29 ++++-------------------------
1 file changed, 4 insertions(+), 25 deletions(-)
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index ef013bcdc7..66ecf5eb55 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -3965,27 +3965,8 @@ exec_prepare_plan(PLpgSQL_execstate *estate,
(void *) expr,
cursorOptions);
if (plan == NULL)
- {
- /* Some SPI errors deserve specific error messages */
- switch (SPI_result)
- {
- case SPI_ERROR_COPY:
- ereport(ERROR,
-
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("cannot COPY to/from
client in PL/pgSQL")));
- break;
- case SPI_ERROR_TRANSACTION:
- ereport(ERROR,
-
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("cannot begin/end
transactions in PL/pgSQL"),
- errhint("Use a BEGIN block
with an EXCEPTION clause instead.")));
- break;
- default:
- elog(ERROR, "SPI_prepare_params failed for
\"%s\": %s",
- expr->query,
SPI_result_code_string(SPI_result));
- break;
- }
- }
+ elog(ERROR, "SPI_prepare_params failed for \"%s\": %s",
+ expr->query, SPI_result_code_string(SPI_result));
if (keepplan)
SPI_keepplan(plan);
expr->plan = plan;
@@ -4129,8 +4110,7 @@ exec_stmt_execsql(PLpgSQL_execstate *estate,
case SPI_ERROR_TRANSACTION:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("cannot begin/end transactions
in PL/pgSQL"),
- errhint("Use a BEGIN block with an
EXCEPTION clause instead.")));
+ errmsg("unsupported transaction
command in PL/pgSQL")));
break;
default:
@@ -4317,8 +4297,7 @@ exec_stmt_dynexecute(PLpgSQL_execstate *estate,
case SPI_ERROR_TRANSACTION:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("cannot begin/end transactions
in PL/pgSQL"),
- errhint("Use a BEGIN block with an
EXCEPTION clause instead.")));
+ errmsg("EXECUTE of transaction
commands is not implemented")));
break;
default:
--
2.17.0
