Acces Methods

These are the methods for BDB::Recnum

Don't mix these methods with methods of BDB::Cursor

Class Methods

open(name = nil, subname = nil, flags = 0, mode = 0, options = {})

create(name = nil, subname = nil, flags = 0, mode = 0, options = {})

new(name = nil, subname = nil, flags = 0, mode = 0, options = {})

open the database

BDB::Recnum.open(name, subname, flags, mode)

is equivalent to

BDB::Recno.open(name, subname, flags, mode,
                "set_flags" => BDB::RENUMBER,
                "set_array_base" => 0)

remove(name, subname = nil)

db_remove(name, subname = nil)

unlink(name, subname = nil)

Removes the database (or subdatabase) represented by the name and subname combination.

If no subdatabase is specified, the physical file represented by name is removed, incidentally removing all subdatabases that it contained.

upgrade(name)

db_upgrade(name)

Upgrade the database

Methods

All this methods has the same syntax than for the class Array

self[nth]

retrieves the nth item from an array. Index starts from zero. If index is the negative, counts backward from the end of the array. The index of the last element is -1. Returns nil, if the nth element is not exist in the array.

self[start..end]

returns an array containing the objects from start to end, including both ends. if end is larger than the length of the array, it will be rounded to the length. If start is out of an array range , returns nil. And if start is larger than end with in array range, returns empty array ([]).

self[start, length]

returns an array containing length items from start. Returns nil if length is negative.

self[nth] = val

changes the nth element of the array into val. If nth is larger than array length, the array shall be extended automatically. Extended region shall be initialized by nil.

self[start..end] = val

replace the items from start to end with val. If val is not an array, the type of val will be converted into the Array using to_a method.

self[start, length] = val

replace the length items from start with val. If val is not an array, the type of val will be converted into the Array using to_a.

self + other

concatenation

self * times

repetition

self - other

substraction

self & other

returns a new array which contains elements belong to both elements.

self | other

join

self << obj

append a new item with value obj. Return self

self <=> other

comparison : return -1, 0 or 1

clear

delete all elements

collect {|item| ..}

Returns a new array by invoking block once for every element, passing each element as a parameter to block. The result of block is used as the given element

collect! {|item| ..}

invokes block once for each element of db, replacing the element with the value returned by block.

concat(other)

append other to the end

delete(val)

delete the item which matches to val

delete_at(pos)

delete the item at pos

delete_if {|x| ...}

delete the item if the block return true

reject!{|x|...}

delete the item if the block return true

each {|x| ...}

iterate over each item

each_index {|i| ...}

iterate over each index

empty?

return true if the db file is empty

fill(val)

set the entire db with val

fill(val, start[, length])

fill the db with val from start

fill(val, start..end)

set the db with val from start to end

include?(val)

returns true if the given val is present

index(val)

returns the index of the item which equals to val. If no item found, returns nil

indexes(index_1,..., index_n)

returns an array consisting of elements at the given indices

indices(index_1,..., index_n)

returns an array consisting of elements at the given indices

join([sep])

returns a string created by converting each element to a string

length

size

return the number of elements of the db file

nitems

return the number of non-nil elements of the db file

pop

pops and returns the last value

push(obj...)

appends obj

replace(other)

replaces the contents of the db file with the contents of other

reverse

returns the array of the items in reverse order

reverse!

replaces the items in reverse order.

reverse_each {|x| ...}

iterate over each item in reverse order

rindex(val)

returns the index of the last item which verify item == val

shift

remove and return the first element

to_a

to_ary

return an Array with all elements

unshift(obj)

insert obj to the front of the db file