From 18043150bea8c294772f96949cf4fd3ae5b42d70 Mon Sep 17 00:00:00 2001
From: firest <enlanubo@gmail.com>
Date: Wed, 17 May 2023 10:55:47 +0800
Subject: [PATCH] fix: cannot access columns exported by FOREACH in DO clause

---
 apps/emqx_rule_engine/src/emqx_rule_runtime.erl      |  4 ++--
 .../emqx_rule_engine/test/emqx_rule_engine_SUITE.erl | 12 ++++++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/apps/emqx_rule_engine/src/emqx_rule_runtime.erl b/apps/emqx_rule_engine/src/emqx_rule_runtime.erl
index d7412d03c..5b7f962fb 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_runtime.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_runtime.erl
@@ -144,14 +144,14 @@ do_apply_rule(
         )
     of
         true ->
-            Collection2 = filter_collection(Columns, InCase, DoEach, Collection),
+            Collection2 = filter_collection(ColumnsAndSelected, InCase, DoEach, Collection),
             case Collection2 of
                 [] ->
                     ok = emqx_metrics_worker:inc(rule_metrics, RuleId, 'failed.no_result');
                 _ ->
                     ok = emqx_metrics_worker:inc(rule_metrics, RuleId, 'passed')
             end,
-            NewEnvs = maps:merge(Columns, Envs),
+            NewEnvs = maps:merge(ColumnsAndSelected, Envs),
             {ok, [handle_action_list(RuleId, Actions, Coll, NewEnvs) || Coll <- Collection2]};
         false ->
             ok = emqx_metrics_worker:inc(rule_metrics, RuleId, 'failed.no_result'),
diff --git a/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl b/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl
index eb253e516..9c3e5513a 100644
--- a/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl
+++ b/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl
@@ -1735,11 +1735,12 @@ t_sqlparse_foreach_7(_Config) ->
         )
     ).
 
+-define(COLL, #{<<"info">> := [<<"haha">>, #{<<"name">> := <<"cmd1">>, <<"cmd">> := <<"1">>}]}).
 t_sqlparse_foreach_8(_Config) ->
     %% Verify foreach-do-incase and cascaded AS
     Sql =
         "foreach json_decode(payload) as p, p.sensors as s, s.collection as c, c.info as info "
-        "do info.cmd as msg_type, info.name as name "
+        "do info.cmd as msg_type, info.name as name, s, c "
         "incase is_map(info) "
         "from \"t/#\" "
         "where s.page = '2' ",
@@ -1748,7 +1749,14 @@ t_sqlparse_foreach_8(_Config) ->
         "{\"info\":[\"haha\", {\"name\":\"cmd1\", \"cmd\":\"1\"}]} } }"
     >>,
     ?assertMatch(
-        {ok, [#{<<"name">> := <<"cmd1">>, <<"msg_type">> := <<"1">>}]},
+        {ok, [
+            #{
+                <<"name">> := <<"cmd1">>,
+                <<"msg_type">> := <<"1">>,
+                <<"s">> := #{<<"page">> := 2, <<"collection">> := ?COLL},
+                <<"c">> := ?COLL
+            }
+        ]},
         emqx_rule_sqltester:test(
             #{
                 sql => Sql,