lua_newtable / lua_settable

Ironica · 2003-08-03T07:06:43

Hey guys =) This function crashes my program, but I don''t totally understand how to do it properly >.< Would like some help understanding it =) I''m getting really confused over calling lua_settable. static int lua_sql(lua_State *L){ if(lua_isstring(L, 1) && mysql != NULL){ if(mysql_query(mysql, lua_tostring(L, 1))){ output(lua_tostring(L, 1)); }else{ MYSQL_RES *result = mysql_store_result(mysql); MYSQL_ROW row; lua_newtable(L); int rowcount = 1; while(row = mysql_fetch_row(result)){ lua_pushnumber(L, rowcount); lua_newtable(L); lua_settable(L, -3); int i = 0; while(row[i]){ lua_pushnumber(L, i + 1); lua_pushstring(L, row[i]); lua_settable(L, -3); i++; } rowcount++; } } } lua_pop(L, 1); return 0; } mysql is a MYSQL*, and will be NULL, if there''s no connection to the database. Basically, this function is supposed to execute the arguement as a sql query. Then return a lua table, which contains any result from the database. I know it doesn''t do that yet, because I''m just testing it so far. Alrighty, let me explain what I think it does (or supposed to do). First checks there''s a connection to the database, and the arguement from Lua is a string. Then executes the arguement as sql query. If it fails, it outputs the query to my program window. If it works, it stores the result, and creates a Lua table on the stack. It loops over, fetching a row from the database. It pushes a number, which should be the key on the table. Then creates a new table, which should be the value of the first table. Then sets the table (that''s in the wrong place for a start, right?). Then loops through each field of the row, pushing the relevant key and value, and setting the table. Doesn''t bother returning it or anything, since it''s just a test. Someone explain to me when to call lua_settable? I should only call it once, once the table is complete, right? If so, that''s obviously the problem, calling it in the loop. Does it place alternate stack values as keys and values of the table? Could really do with some help understanding it =) hehe...