From 4b7a5bbf536396c39add1415f3f3f34fbdf702dc Mon Sep 17 00:00:00 2001
From: DDDHuang <44492639+DDDHuang@users.noreply.github.com>
Date: Thu, 21 Apr 2022 21:26:35 +0800
Subject: [PATCH] fix: bad empty map

---
 apps/emqx_authz/src/emqx_authz_mysql.erl      |  4 ++--
 .../src/emqx_connector_mysql.erl              | 22 +++++++++++--------
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/apps/emqx_authz/src/emqx_authz_mysql.erl b/apps/emqx_authz/src/emqx_authz_mysql.erl
index db6acb347..1bdf511a5 100644
--- a/apps/emqx_authz/src/emqx_authz_mysql.erl
+++ b/apps/emqx_authz/src/emqx_authz_mysql.erl
@@ -51,7 +51,7 @@ description() ->
 
 init(#{query := SQL} = Source0) ->
     {PrepareSQL, TmplToken} = emqx_authz_utils:parse_sql(SQL, '?', ?PLACEHOLDERS),
-    Source = Source0#{prepare_statement => #{?MODULE => PrepareSQL}},
+    Source = Source0#{prepare_statement => #{?PREPARE_KEY => PrepareSQL}},
     case emqx_authz_utils:create_resource(emqx_connector_mysql, Source) of
         {error, Reason} ->
             error({load_config_error, Reason});
@@ -74,7 +74,7 @@ authorize(
     }
 ) ->
     RenderParams = emqx_authz_utils:render_sql_params(TmplToken, Client),
-    case emqx_resource:query(ResourceID, {prepared_query, ?MODULE, RenderParams}) of
+    case emqx_resource:query(ResourceID, {prepared_query, ?PREPARE_KEY, RenderParams}) of
         {ok, _Columns, []} ->
             nomatch;
         {ok, Columns, Rows} ->
diff --git a/apps/emqx_connector/src/emqx_connector_mysql.erl b/apps/emqx_connector/src/emqx_connector_mysql.erl
index b8ca93104..f44e92413 100644
--- a/apps/emqx_connector/src/emqx_connector_mysql.erl
+++ b/apps/emqx_connector/src/emqx_connector_mysql.erl
@@ -86,6 +86,7 @@ on_start(InstId, #{server := {Host, Port},
                {pool_size, PoolSize}],
     PoolName = emqx_plugin_libs_pool:pool_name(InstId),
     Prepares = maps:get(prepare_statement, Config, #{}),
+    io:format("Prepares ~p~n", [Prepares]),
     State = init_prepare(#{poolname => PoolName, prepare_statement => Prepares}),
     case emqx_plugin_libs_pool:start_pool(PoolName, ?MODULE, Options ++ SslOpts) of
         ok              -> {ok, State};
@@ -181,17 +182,20 @@ connect(Options) ->
 to_server(Str) ->
     emqx_connector_schema_lib:parse_server(Str, ?MYSQL_HOST_OPTIONS).
 
-init_prepare(State = #{prepare_statement := #{}}) ->
-    State;
 init_prepare(State = #{prepare_statement := Prepares, poolname := PoolName}) ->
-    case prepare_sql(Prepares, PoolName) of
-        ok ->
+    case maps:size(Prepares) of
+        0 ->
             State;
-        {error, Reason} ->
-            LogMeta = #{msg => <<"MySQL init prepare statement failed">>, reason => Reason},
-            ?SLOG(error, LogMeta),
-            %% mark the prepare_statement as failed
-            State#{prepare_statement => {error, Prepares}}
+        _ ->
+            case prepare_sql(Prepares, PoolName) of
+                ok ->
+                    State;
+                {error, Reason} ->
+                    LogMeta = #{msg => <<"MySQL init prepare statement failed">>, reason => Reason},
+                    ?SLOG(error, LogMeta),
+                    %% mark the prepare_statement as failed
+                    State#{prepare_statement => {error, Prepares}}
+            end
     end.
 
 prepare_sql(Prepares, PoolName) when is_map(Prepares) ->