使用单引号和双引号的混合创建粘合字符串

Question

我正在尝试使用 R 中的 glue 包创建一个字符串这是 'single' 和 "double" 引号的混合。

作为代表，考虑以下类型的 SQL 查询我要构建的字符串：

CREATE TABLE fact_final_table AS 
(SELECT tab1.id,
    AVG(tab2."MV") FILTER (WHERE tab2.record_dt BETWEEN tab1.start_date::date - integer '7'
                                                      AND tab1.start_date::date - integer '1') AS "mv_avg_1w",
    AVG(tab2."MV") FILTER (WHERE tab2.record_dt BETWEEN tab1.start_date::date - integer '14'
                                                      AND tab1.start_date::date - integer '1') AS "mv_avg_2w"
FROM (SELECT id,
             start_date,
             point
      FROM base_tab
      WHERE mpfb.start_date::date >= '01-01-2000'::date) AS tab1
LEFT JOIN ghcnd_observations AS tab2
    ON (tab2.record_dt BETWEEN (tab1.start_date::date - integer '180')
                           AND (tab1.start_date::date - integer '1')
        AND ST_DWithin(tab1.point, tab2.location, 0.5))
GROUP BY tab1.id);

如你所见，它是单引号和双引号的组合，正如上面所写的那样，这些字面意思是很重要的。为了例如 tab2."MV" 有双引号，而 tab1.start_date::date - integer '7' AND tab1.start_date::date - integer '1' 有单引号需要按字面意思保留的引用。

这个字符串也需要使用参数来构建。我在 R 中使用 glue 尝试了以下操作，但无法获取上班。

var1       <- "MV"
var1_lowcase <- "mv"
lag_days   <- 180
var_date   <- as.Date("2000-01-01")
var_dwithin <- 0.5

glue::glue(
"CREATE TABLE fact_final_table AS 
(SELECT tab1.id,
    AVG(tab2."{var1}") FILTER (WHERE tab2.record_dt BETWEEN tab1.start_date::date - integer '7'
                           AND tab1.start_date::date - integer '1') AS "{var1_lowcase}_avg_1w",
    AVG(tab2."{var1}") FILTER (WHERE tab2.record_dt BETWEEN tab1.start_date::date - integer '14'
                           AND tab1.start_date::date - integer '1') AS "{var1_lowcase}_avg_2w"
    FROM (SELECT id,
          start_date,
          point
          FROM base_tab
          WHERE mpfb.start_date::date >= '{format(var_date, "%d-%m-%Y")}'::date) AS tab1
    LEFT JOIN ghcnd_observations AS tab2
    ON (tab2.record_dt BETWEEN (tab1.start_date::date - integer '{lag_days}')
        AND (tab1.start_date::date - integer '1')
        AND ST_DWithin(tab1.point, tab2.location, {var_dwithin}))
    GROUP BY tab1.id);")

不幸的是，由于 single/double 引号不存在，这不起作用在 glue::glue(...).

中正确转义

任何人都可以在这里提供最少的帮助吗打破所需的输出字符串？我不确定这是否容易可行的。我将不胜感激任何其他 tidy 方法，例如例如，也使用 stringr，因为我希望它 %>% 友好。我简单地看了 glue::glue_sql 但不知道如何直接在这里应用它。如果能在此处了解如何使用它，我将不胜感激。

Answer 1

尝试转义双引号：

glue::glue(
   "CREATE TABLE fact_final_table AS 
   (SELECT tab1.id,
   AVG(tab2.\"{var1}\") FILTER (WHERE tab2.record_dt BETWEEN tab1.start_date::date - integer '7'
   AND tab1.start_date::date - integer '1') AS \"{var1_lowcase}_avg_1w\",
   AVG(tab2.\"{var1}\") FILTER (WHERE tab2.record_dt BETWEEN tab1.start_date::date - integer '14'
   AND tab1.start_date::date - integer '1') AS \"{var1_lowcase}_avg_2w\"
   FROM (SELECT id,
         start_date,
          point
   FROM base_tab
    WHERE mpfb.start_date::date >= '{format(var_date, \"%d-%m-%Y\")}'::date) 
  AS tab1
   LEFT JOIN ghcnd_observations AS tab2
   ON (tab2.record_dt BETWEEN (tab1.start_date::date - integer '{lag_days}')
   AND (tab1.start_date::date - integer '1')
   AND ST_DWithin(tab1.point, tab2.location, {var_dwithin}))
   GROUP BY tab1.id);")

其中 returns :

#CREATE TABLE fact_final_table AS 
#(SELECT tab1.id,
#AVG(tab2."MV") FILTER (WHERE tab2.record_dt BETWEEN tab1.start_date::date #- integer '7'
#AND tab1.start_date::date - integer '1') AS "mv_avg_1w",
#AVG(tab2."MV") FILTER (WHERE tab2.record_dt BETWEEN tab1.start_date::date #- integer '14'
#AND tab1.start_date::date - integer '1') AS "mv_avg_2w"
#FROM (SELECT id,
#start_date,
#point
#FROM base_tab
#WHERE mpfb.start_date::date >= '01-01-2000'::date) AS tab1
#LEFT JOIN ghcnd_observations AS tab2
#ON (tab2.record_dt BETWEEN (tab1.start_date::date - integer '180')
#AND (tab1.start_date::date - integer '1')
#AND ST_DWithin(tab1.point, tab2.location, 0.5))
#GROUP BY tab1.id);

Answer 2

所以我从昨天开始更详细地研究了这个问题，并且看起来 glue 确实具有单身的功能和双引号显式即 glue::single_quote() 和 glue::double_quote().

与@ronakshah 的（有帮助的）回复类似，我设法以下，更明确（为了代码可读性）：

var1       <- "MV"
var1_lowcase <- "mv"
lag_days   <- 180
var_date   <- as.Date("2000-01-01")
var_dwithin <- 0.5

glue::glue(
    "CREATE TABLE fact_final_table AS 
   (SELECT tab1.id,
   AVG(tab2.{glue::double_quote(var1)}) FILTER (WHERE tab2.record_dt BETWEEN tab1.start_date::date - integer '7'
   AND tab1.start_date::date - integer '1') AS {glue::double_quote(glue::glue({var1_lowcase},'_avg_1w'))},
   AVG(tab2.{glue::double_quote(var1)}) FILTER (WHERE tab2.record_dt BETWEEN tab1.start_date::date - integer '14'
   AND tab1.start_date::date - integer '1') AS {glue::double_quote(glue::glue({var1_lowcase},'_avg_2w'))}
   FROM (SELECT id,
         start_date,
          point
   FROM base_tab
    WHERE mpfb.start_date::date >= {glue::single_quote(format(var_date, '%d-%m-%Y'))}::date) 
  AS tab1
   LEFT JOIN ghcnd_observations AS tab2
   ON (tab2.record_dt BETWEEN (tab1.start_date::date - integer '{lag_days}')
   AND (tab1.start_date::date - integer '1')
   AND ST_DWithin(tab1.point, tab2.location, {var_dwithin}))
   GROUP BY tab1.id);")

其中 returns 我需要的主要字符串。希望这可以帮助别人谁有类似的 glue 要求。

使用单引号和双引号的混合创建粘合字符串

Create glue string with mixture of single and double quotes

r

tidyverse

r-glue