PivotalR (version 0.1.18.5)

is.na-method: Query if the entries in a table are NULL

Description

This function is equivalent to an SQL query that checks if the entries in a table are NULL.

Usage

# S4 method for db.obj
is.na(x)

Arguments

x

The signature of the method. A db.obj object.

Value

The return value is a db.Rquery object.

Details

is.na() creates a db.Rquery object where the NULL entries in a db.obj object are TRUE, and other the entries are FALSE.

See Also

lk or lookat Displays the contents of a db.obj object.

Examples

# NOT RUN {
<!-- %% @test .port Database port number -->
<!-- %% @test .dbname Database name -->
## set up the database connection
## Assume that .port is port number and .dbname is the database name
cid <- db.connect(port = .port, dbname = .dbname, verbose = FALSE)

## create a temp table from the example data.frame "abalone"
x <- as.db.data.frame(abalone, conn.id = cid, verbose = FALSE)

#Query which entries of x are NULL
is.na(x)

y <- x
y[is.na(y)] <- 3

z <- x
z[is.na(x$height),"height"] <- 23

db.disconnect(cid, verbose = FALSE)
# }