Retrieve all items that have been entered in the db so far by booklet and position in the booklet
a dexter database or any object form which a design can be inferred
return format, see below
variable that defines the rows, ignored if format='long'
variable that defines the columns, ignored if format='long'
If set, missing values will be replaced with this value, ignored if format='long'
A data.frame with the design. The contents depend on the rows, columns and format parameters
if format
is 'long'
a data.frame with columns: booklet_id, item_id, item_position (if available)
if format
is 'wide'
a data.frame with the rows defined by the rows
parameter and
the columns by the columns
parameter, with the remaining variable (i.e. item_id, booklet_id or item_position)
making up the cells