rquery (version 0.2.0)

select_columns: Make a select columns node (not a relational operation).

Description

Make a select columns node (not a relational operation).

Usage

select_columns(source, columns)

Arguments

source

source to select from.

columns

list of distinct column names.

Value

select columns node.

Examples

# NOT RUN {
my_db <- DBI::dbConnect(RSQLite::SQLite(), ":memory:")
d <- dbi_copy_to(my_db, 'd',
                data.frame(AUC = 0.6, R2 = 0.2))
eqn <- select_columns(d, 'AUC')
cat(format(eqn))
sql <- to_sql(eqn, my_db)
cat(sql)
DBI::dbGetQuery(my_db, sql)
DBI::dbDisconnect(my_db)

# }