feat: Add dbplyr translations for clock::add_days(), clock::add_years(), clock::get_day(), clock::get_month(), and clock::get_year()

[edward-burn]

For isssue #116

• add translations for clock::add_days() and clock::add_years()
• add associated tests

[edward-burn]

@krlmlr I have open this for issue #116. Hopefully it is ready for review.

[krlmlr]

Thanks for looking into it!

[krlmlr]

Suggested change

	expect_equal(translate(add_years(x, 2L)), sql(r"{date_add(x, INTERVAL '2 day')}"))
	expect_equal(translate(add_days(x, 2L)), sql(r"{date_add(x, INTERVAL '2 day')}"))

What happens with negative days? It's also interesting to see an integration test -- running an actual query with negative months, let's say.

[edward-burn]

@krlmlr sure, here's a reprex (comparing clock's behaviour for a dataframe with how this duckdb implementation works) and it seems to work as expected for both adding days and years as well as substracting them

options(conflicts.policy = list(warn = FALSE))
library(DBI)
#> Warning: package 'DBI' was built under R version 4.2.3
library(RPostgres)
#> Warning: package 'RPostgres' was built under R version 4.2.3
library(dplyr)
#> Warning: package 'dplyr' was built under R version 4.2.3
library(dbplyr)
#> Warning: package 'dbplyr' was built under R version 4.2.3
library(clock)
#> Warning: package 'clock' was built under R version 4.2.3
library(duckdb)

con <- DBI::dbConnect(duckdb(), path = ":memory:")
test_data <- data.frame(
  person = 1L,
  date_1 = as.Date("2000-01-01")
)
test_data |> 
  mutate(date_plus_two_days  = clock::add_days(date_1, 2), 
         date_plus_two_years = clock::add_years(date_1, 2),
         date_minus_two_days  = clock::add_days(date_1, -2), 
         date_minus_two_years = clock::add_years(date_1, -2)) |> 
  dplyr::glimpse()
#> Rows: 1
#> Columns: 6
#> $ person               <int> 1
#> $ date_1               <date> 2000-01-01
#> $ date_plus_two_days   <date> 2000-01-03
#> $ date_plus_two_years  <date> 2002-01-01
#> $ date_minus_two_days  <date> 1999-12-30
#> $ date_minus_two_years <date> 1998-01-01

db_test_data <- copy_to(con, test_data, overwrite = TRUE)
db_test_data |> 
  mutate(date_plus_two_days  = clock::add_days(date_1, 2), 
         date_plus_two_years = clock::add_years(date_1, 2),
         date_minus_two_days  = clock::add_days(date_1, -2), 
         date_minus_two_years = clock::add_years(date_1, -2)) |> 
  dplyr::glimpse()
#> Rows: ??
#> Columns: 6
#> Database: DuckDB v0.10.3-dev163 [eburn@Windows 10 x64:R 4.2.1/:memory:]
#> $ person               <int> 1
#> $ date_1               <date> 2000-01-01
#> $ date_plus_two_days   <dttm> 2000-01-03
#> $ date_plus_two_years  <dttm> 2002-01-01
#> $ date_minus_two_days  <dttm> 1999-12-30
#> $ date_minus_two_years <dttm> 1998-01-01

^{Created on 2024-05-03 with reprex v2.0.2}

[krlmlr]

Thanks for the example. Having a code like this in a test would be useful too.

[codecov-commenter]

Codecov Report

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[edward-burn]

@krlmlr have added those examples as tests. I have also added the related clock functions get_day, get_month, get_year to this pr (hope that is not expanding it too much, can remove if it is)

[edward-burn]

Hi @krlmlr, hopefully this is getting there. I saw a note Undefined global functions or variables: DATE_PART, so I switched to using build_sql throughout which hopefully should fix that .

[krlmlr]

Thank you so much for your patience!