diff options
Diffstat (limited to '')
| -rw-r--r-- | contrib/postgres_fdw/deparse.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c index 8f4d8a5..d7235a5 100644 --- a/contrib/postgres_fdw/deparse.c +++ b/contrib/postgres_fdw/deparse.c @@ -3624,13 +3624,12 @@ appendOrderByClause(List *pathkeys, bool has_final_sort, { ListCell *lcell; int nestlevel; - const char *delim = " "; StringInfo buf = context->buf; + bool gotone = false; /* Make sure any constants in the exprs are printed portably */ nestlevel = set_transmission_modes(); - appendStringInfoString(buf, " ORDER BY"); foreach(lcell, pathkeys) { PathKey *pathkey = lfirst(lcell); @@ -3664,6 +3663,26 @@ appendOrderByClause(List *pathkeys, bool has_final_sort, em_expr = em->em_expr; /* + * If the member is a Const expression then we needn't add it to the + * ORDER BY clause. This can happen in UNION ALL queries where the + * union child targetlist has a Const. Adding these would be + * wasteful, but also, for INT columns, an integer literal would be + * seen as an ordinal column position rather than a value to sort by. + * deparseConst() does have code to handle this, but it seems less + * effort on all accounts just to skip these for ORDER BY clauses. + */ + if (IsA(em_expr, Const)) + continue; + + if (!gotone) + { + appendStringInfoString(buf, " ORDER BY "); + gotone = true; + } + else + appendStringInfoString(buf, ", "); + + /* * Lookup the operator corresponding to the strategy in the opclass. * The datatype used by the opfamily is not necessarily the same as * the expression type (for array types for example). @@ -3677,7 +3696,6 @@ appendOrderByClause(List *pathkeys, bool has_final_sort, pathkey->pk_strategy, em->em_datatype, em->em_datatype, pathkey->pk_opfamily); - appendStringInfoString(buf, delim); deparseExpr(em_expr, context); /* @@ -3687,7 +3705,6 @@ appendOrderByClause(List *pathkeys, bool has_final_sort, appendOrderBySuffix(oprid, exprType((Node *) em_expr), pathkey->pk_nulls_first, context); - delim = ", "; } reset_transmission_modes(nestlevel); } |