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PostgreSQL backend

Source: R/backend-postgres.R
backend-postgres.Rd

This backend supports PostgreSQL databases, typically accessed via a PqConnection created by DBI::dbConnect(). Use dialect_postgres() with lazy_frame() to see simulated SQL without connecting to a live database.

Key differences for this backend are:

  • Many stringr functions

  • lubridate date-time extraction functions

  • More standard statistical summaries

See vignette("translation-function") and vignette("translation-verb") for details of overall translation technology.

Usage

dialect_postgres()

simulate_postgres()

Examples

library(dplyr, warn.conflicts = FALSE)

lf <- lazy_frame(a = TRUE, b = 1, c = 2, d = "z", con = dialect_postgres())
lf |> summarise(x = sd(b, na.rm = TRUE))
#> <SQL>
#> SELECT STDDEV_SAMP("b") AS "x"
#> FROM "df"
lf |> summarise(y = cor(b, c), z = cov(b, c))
#> <SQL>
#> SELECT CORR("b", "c") AS "y", COVAR_SAMP("b", "c") AS "z"
#> FROM "df"