Function lua_sql_step

lua/sp.c:1331–1424

** This returns dbrow or nil on end of result set. There is no way to signal ** error. I'll throw runtime error -- seems appropriate, SQL encountered some ** runtime error (type conversion, row corruption, etc). SPs probably not ** written to handle this situation anyway. */

** written to handle this situation anyway.
*/
static int lua_sql_step(Lua lua, sqlite3_stmt *stmt)
{
    SP sp = getsp(lua);
    struct sqlclntstate *clnt = sp->clnt;
    int rc = sqlite3_maybe_step(clnt, stmt);

    if (rc == SQLITE_DONE) {
        lua_end_step(clnt, sp, stmt);
        return rc;
    } else if (rc != SQLITE_ROW) {
        return luaL_error(lua, sqlite3_errmsg(getdb(sp)));
    } else {
        lua_another_step(clnt, stmt, rc);
    }

    lua_newtable(lua);

    int ncols = column_count(clnt, stmt);
    for (int col = 0; col < ncols; col++) {
        int type = column_type(clnt, stmt, col);
        switch (type) {
        case SQLITE_NULL: {
            int sqltype =
                sqlite_str_to_type(sqlite3_column_decltype(stmt, col));
            luabb_pushnull(lua, sqlite_type_to_dbtype(sqltype));
            break;
        }
        case SQLITE_INTEGER: {
            long long ival = column_int64(clnt, stmt, col);
            luabb_pushinteger(lua, ival);
            break;
        }
        case SQLITE_FLOAT: {
            double dval = column_double(clnt, stmt, col);
            luabb_pushreal(lua, dval);
            break;
        }
        case SQLITE_TEXT: {
            char *tval = (char *)column_text(clnt, stmt, col);
            luabb_pushcstring(lua, tval);
            break;
        }
        case SQLITE_DATETIME: {
            cdb2_client_datetime_t cdt;
            datetime_t datetime;
            const dttz_t *dt = column_datetime(clnt, stmt, col);
            dttz_to_client_datetime(dt, clnt_tzname(clnt, stmt), &cdt);
            client_datetime_to_datetime_t(&cdt, &datetime, 0);
            luabb_pushdatetime(lua, &datetime);
            break;
        }
        case SQLITE_DATETIMEUS: {
            cdb2_client_datetimeus_t cdt;
            datetime_t datetime;
            const dttz_t *dt = column_datetime(clnt, stmt, col);
            dttz_to_client_datetimeus(dt, clnt_tzname(clnt, stmt), &cdt);
            client_datetimeus_to_datetime_t(&cdt, &datetime, 0);
            luabb_pushdatetime(lua, &datetime);