PivotalR (version 0.1.18.5)

dim-methods: Dimension of a table

Description

Display the dimension of the table that a db.table object points to.

Usage

# S4 method for db.table
dim(x)
# S4 method for db.view
dim(x)
# S4 method for db.Rquery
dim(x)

Arguments

x

A db.obj. Only for db.table object, this function gives the dimension of table that x points to. For db.view and db.Rquery objects, an error message is raised.

Value

A two-integer array, where the first integer is the number of rows and the second integer is the number of columns.

See Also

'>db.obj, '>db.data.frame, '>db.table, '>db.view, '>db.Rquery are the class hierarchy structure of this package.

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 table from the example data.frame "abalone"
delete("abalone", conn.id = cid)
x <- as.db.data.frame(abalone, "abalone", conn.id = cid, verbose = FALSE)
## preview of a table
lk(x, nrows = 10) # extract 10 rows of data

## get names of all columns
dim(x)

dim(x[,1:3])

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