theta_join: Make a theta_join node.

In rquery: Relational Query Generator for Data Manipulation at Scale

Make a theta_join node.

Description

Theta join is a join on an arbitrary predicate.

Usage

theta_join(
  a,
  b,
  expr,
  ...,
  jointype = "INNER",
  suffix = c("_a", "_b"),
  env = parent.frame()
)

theta_join_nse(
  a,
  b,
  expr,
  ...,
  jointype = "INNER",
  suffix = c("_a", "_b"),
  env = parent.frame()
)

Arguments

a	source to select from.
b	source to select from.
expr	unquoted join condition
...	force later arguments to be by name
jointype	type of join ('INNER', 'LEFT', 'RIGHT', 'FULL').
suffix	character length 2, suffices to disambiguate columns.
env	environment to look for values in.

Value

theta_join node.

Examples

if (requireNamespace("DBI", quietly = TRUE) && requireNamespace("RSQLite", quietly = TRUE)) {
  my_db <- DBI::dbConnect(RSQLite::SQLite(), ":memory:")
  d1 <- rq_copy_to(my_db, 'd1',
                    data.frame(AUC = 0.6, R2 = 0.2))
  d2 <- rq_copy_to(my_db, 'd2',
                    data.frame(AUC2 = 0.4, R2 = 0.3))
  optree <- theta_join(d1, d2, AUC >= AUC2)
  cat(format(optree))
  sql <- to_sql(optree, my_db)
  cat(sql)
  print(DBI::dbGetQuery(my_db, sql))
  DBI::dbDisconnect(my_db)
}

rquery documentation built on Aug. 20, 2023, 9:06 a.m.