---
title: 数据分析
---

```{r}
#| echo: false
#| execute: false
if (FALSE) {
  require(cctdb)
  require(tidyverse)
  conn <- cctdb::get_dbconn("nationalairquality")
  metadf <- tbl(conn, "metadf") |>
    collect()
  airqualitydf <- tbl(conn, "airqualitydf") |>
    filter(datetime > "2024-03-18") |>
    filter(datetime < "2024-03-20") |>
    collect()
  writexl::write_xlsx(list(metadf = metadf,
    airqualitydf = airqualitydf),
    "../data/airquality.xlsx")
}
```