Create a null_replace node.

Source: R/null_replace.R

Replace NA/NULL is specified columns with the given replacement value.

null_replace(src, cols, value, ..., note_col = NULL, env = parent.frame())

Arguments

src

relop or data.frame data source.
cols

character, columns to work on.
value

scalar, value to write.
...

force later arguments to bind by name.
note_col

character, if not NULL record number of columns altered per-row in this column.
env

environment to look to.

Value

null_replace node or data.frame.

See also

count_null_cols, mark_null_cols

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(A = c(NA, 2, 3, NA), B = c(3, NA, 4, NA)))
  optree <- null_replace(d1, qc(A, B),
                         0.0, note_col = "alterations")
  cat(format(optree))
  sql <- to_sql(optree, my_db)
  cat(sql)
  print(DBI::dbGetQuery(my_db, sql))
  DBI::dbDisconnect(my_db)
}

#> mk_td("d1", c(
#>   "A",
#>   "B")) %.>%
#>  null_replace(.; A,
#>   B: 0;  alterations)
#> SELECT
#>  CASE WHEN `tsql_49003264259016100656_0000000000`.`A` IS NULL THEN 0 ELSE `tsql_49003264259016100656_0000000000`.`A` END AS `A`,
#>  CASE WHEN `tsql_49003264259016100656_0000000000`.`B` IS NULL THEN 0 ELSE `tsql_49003264259016100656_0000000000`.`B` END AS `B`,
#>  0 + 
#>  ( CASE WHEN `tsql_49003264259016100656_0000000000`.`A` IS NULL THEN 1 ELSE 0 END ) + 
#>  ( CASE WHEN `tsql_49003264259016100656_0000000000`.`B` IS NULL THEN 1 ELSE 0 END ) AS `alterations`
#> 
#> FROM (
#>  SELECT
#>   `A`,
#>   `B`
#>  FROM
#>   `d1`
#> ) tsql_49003264259016100656_0000000000
#>   A B alterations
#> 1 0 3           1
#> 2 2 0           1
#> 3 3 4           0
#> 4 0 0           2