I'm running a MySQL query which always returns 4 rows:
row->name
, row->date
, row->ip
, row->custom
What I want to achieve is create a simple table basing on the above results so it would look like:
{
"name" = result of row->name,
"date" = result of row->date,
"ip" = result of row->ip,
"custom" = result of row->custom
}
I have tried multiple possibilities, but the examples posted are really varied and I got a problems making it working.
My last unsuccessful try:
lua_createtable(L, 0, 4);
top = lua_gettop(L);
lua_pushstring(L, "name");
lua_pushstring(L, row->name);
lua_pushstring(L, "date");
lua_pushnumber(L, row->date);
lua_pushstring(L, "ip");
lua_pushstring(L, row->ip);
lua_pushstring(L, "custom");
lua_pushstring(L, row->custom);
lua_settable(L, top);
As I mentioned in comment, lua_settable()
takes care only of one key, value
pair. Must repeat that if You need more.
I'd prefer saving the Lua stack space like this:
lua_createtable(L, 0, 4);
lua_pushstring(L, "name");
lua_pushstring(L, row->name);
lua_settable(L, -3); /* 3rd element from the stack top */
lua_pushstring(L, "date");
lua_pushstring(L, row->date);
lua_settable(L, -3);
lua_pushstring(L, "ip");
lua_pushstring(L, row->ip);
lua_settable(L, -3);
lua_pushstring(L, "custom");
lua_pushstring(L, row->custom);
lua_settable(L, -3);
/* We still have table left on top of the Lua stack. */
Also, You could write some kind of C struct iterator or something.
NOTE: if this is for some kind of Lua wrapper - You should ensure standardized way of doing that. In the following example applied @lhf comment about shortening it a bit:
int
l_row_push(lua_State *l)
{
lua_createtable(L, 0, 4); /* creates and pushes new table on top of Lua stack */
lua_pushstring(L, row->name); /* Pushes table value on top of Lua stack */
lua_setfield(L, -2, "name"); /* table["name"] = row->name. Pops key value */
lua_pushstring(L, row->date);
lua_setfield(L, -2, "date");
lua_pushstring(L, row->ip);
lua_setfield(L, -2, "ip");
lua_pushstring(L, row->custom);
lua_setfield(L, -2, "custom");
/* Returning one table which is already on top of Lua stack. */
return 1;
}
EDIT: Fixes usage of lua_setfield()
by @lhf note. Thanks!
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