使用单引号和双引号混合创建粘合字符串

Posted 2023-02-13

【中文标题】使用单引号和双引号混合创建粘合字符串

【英文标题】：Create glue string with mixture of single and double quotes使用单引号和双引号混合创建粘合字符串

【发布时间】：2020-08-22 05:48:38

【相关技术】：@tags@

【问题描述】：

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。

作为一个代表，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， 这对于按照上面所写的字面意思进行保存很重要。为了 例如tab2."MV" 有双引号，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号。

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，但无法得到它 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，由于没有单引号/双引号，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 中断所需的输出字符串？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，因为我希望这对%>% 友好。 我已经简要地查看了glue::glue_sql，但不知道如何直接 在这里应用它。如果适用，我将不胜感激在此处了解如何使用它。

【参考方案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);")

返回：

#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);

【讨论】：

我很欣赏这个答案。我昨天研究了类似的方法，发现使用glue::single_quote() 和glue::double_quote 函数有更明确的方法。请参阅下面的答案，我可能会选择

【参考方案2】：

所以我从昨天开始更详细地研究了这个问题，并且 看来glue 确实具有make single and double quotes explicit 的功能，即glue::single_quote() 和 glue::double_quote().

类似于@ronakshah 的（有用的）回应，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);")

返回我需要的主字符串。希望这对其他人有帮助 谁有类似的glue 要求。