Merge pull request #3296 from robotspace/develop

Update query api for Lua connector.

README.md

@@ -169,6 +169,7 @@ The TDengine community has also kindly built some of their own connectors! Follo
 
 - [Rust Connector](https://github.com/taosdata/TDengine/tree/master/tests/examples/rust)
 - [.Net Core Connector](https://github.com/maikebing/Maikebing.EntityFrameworkCore.Taos)
+- [Lua Connector](https://github.com/taosdata/TDengine/tree/develop/tests/examples/lua)
 
 # How to run the test cases and how to add a new test case?
   TDengine's test framework and all test cases are fully open source.

tests/examples/lua/lua_connector.c

@@ -58,8 +58,10 @@ static int l_query(lua_State *L){
   int table_index = lua_gettop(L);
 
   //  printf("receive command:%s\r\n",s);
-  if(taos_query(taos, s)!=0){
-    printf("failed, reason:%s\n", taos_errstr(taos));
+    result = taos_query(taos,s);
+    int32_t code = taos_errno(result);
+  if( code != 0){
+    printf("failed, reason:%s\n", taos_errstr(result));
     lua_pushnumber(L, -1);
     lua_setfield(L, table_index, "code");    
     lua_pushstring(L, taos_errstr(taos));
@@ -69,24 +71,13 @@ static int l_query(lua_State *L){
     
   }else{
     //printf("success to query.\n");
-    result = taos_use_result(taos);
-
-    if (result == NULL) {
-      printf("failed to get result, reason:%s\n", taos_errstr(taos));
-      lua_pushnumber(L, -2);
-      lua_setfield(L, table_index, "code");    
-      lua_pushstring(L, taos_errstr(taos));
-      lua_setfield(L, table_index, "error");    
-      return 1;
-    }
-
     TAOS_ROW    row;
     int         rows = 0;
-    int         num_fields = taos_field_count(taos);
+    int         num_fields = taos_field_count(result);
     TAOS_FIELD *fields = taos_fetch_fields(result);
     char        temp[256];
 
-    int affectRows = taos_affected_rows(taos);
+    int affectRows = taos_affected_rows(result);
     //    printf(" affect rows:%d\r\n", affectRows);
     lua_pushnumber(L, 0);
     lua_setfield(L, table_index, "code");
@@ -155,15 +146,13 @@ static int l_query(lua_State *L){
 }
 
 void stream_cb(void *param, TAOS_RES *result, TAOS_ROW row){
-
   struct cb_param* p = (struct cb_param*) param;
   TAOS_FIELD *fields = taos_fetch_fields(result);
   int         numFields = taos_num_fields(result);
 
+  printf("\nnumfields:%d\n", numFields);
   printf("\n\r-----------------------------------------------------------------------------------\n");
 
-  // printf("r:%d, L:%d\n",p->callback, p->state);
-
   lua_State *L = p->state;
   lua_rawgeti(L, LUA_REGISTRYINDEX, p->callback);
 

tests/examples/lua/test.lua

@@ -15,7 +15,7 @@ else
    conn = res.conn
 end
 
-local res = driver.query(conn,"drop database demo")
+local res = driver.query(conn,"drop database if exists demo")
 
 res = driver.query(conn,"create database demo")
 if res.code ~=0 then
@@ -106,7 +106,7 @@ end
 
 --From now on we begin continous query in an definite (infinite if you want) loop.
 local loop_index = 0
-while loop_index < 20 do
+while loop_index < 10 do
    local t = os.time()*1000
    local v = loop_index
    res = driver.query(conn,string.format("INSERT INTO therm1 VALUES (%d, %d)",t,v))