# Io Reference

Databases / QDBM / QDBM

|  | An ordered key/value database that supports transactions and arbitrary kay and value sizes.

abort

Abort transaction. Returns self
at(keySymbol)

Returns a Sequence for the value at the given key or nil if there is no such key.
atPut(keySymbol, valueSequence)

Sets the value of valueSequence with the key keySymbol. Returns self.
atRemove(keySymbol)

Removes the specified key. Returns self
begin

Begin transaction. Returns self
close

Closes the database.
commit

Commit transaction. Returns self
cursorFirst

Move cursor to first record. Returns self
cursorJumpBackward(key)

Move cursor to previous record around key. Returns self
cursorJumpForward(key)

Move cursor to next record around key. Returns self
cursorKey

Returns current cursor key or nil.
cursorLast

Move cursor to last record. Returns self
cursorNext

Move cursor to next record. Returns true if there is another key, or false if there is no next record.
cursorPrevious

Move cursor to previous record. Returns true if there is another key, or false if there is no previous record.
cursorPut(value)

Sets the value at the current cursor postion. Returns self.
cursorRemove

Removes the current cursor postion. Returns self.
cursorValue

Returns current cursor value or nil.
name

Returns the name of the database.
open(path)

Opens the database.
optimize

Optimizes the database. Returns self
size

Returns number of records in database. Returns self
sizeAt(keySymbol)

Returns the size of the value at the given key or nil if there is no such key.
sync

Syncs the database. Returns self