Simple database: Difference between revisions

=={{header|Julia}}==

Command line CSV based simple database. The file used contained:<pre>

Name,Birthdate,State,Relation,Email

Sally Whittaker,1988-12-05,Illinois,friend,sally@mail.com

Belinda Jameson,1994-02-17,California,family,beljames@example.com

Jeff Bragg,2018-10-10,Texas,family,jb@texas.edu

Sandy Allen,2002-03-09,Colorado,friend,sandya@mail.com

Fred Kobo,1967-10-10,Colorado,friend,fkobo@example.net

<lang julia>using CSV, DataFrames, ArgParse, Dates

setting = ArgParseSettings()

@add_arg_table setting begin

"--add"

help = "add an entry, within double quotes, comma separated as \"name,birthdate,state,relation,email\" with birthdate as yyyy-mm-dd"

"--latest"

action = :store_true

nargs = 0

help = "print latest (last) entry"

"--latestfriend"

action = :store_true

nargs = 0

help = "print last friend listed"

"--latestfamily"

action = :store_true

nargs = 0

help = "print last family member listed"

"--listbyage"

action = :store_true

nargs = 0

help = "print all ages and entries in birth order"

end

const filename = "example.csv"

const df = CSV.File(filename, dateformat="yyyy-mm-dd") |> DataFrame

const commands = parse_args(setting)

if length(ARGS) == 0

ArgParse.show_help(setting)

end

const changeflag = [false]

for (k, v) in commands

if k == "add" && v != nothing

newrow = Vector{Any}(split(v, r","))

if length(newrow) == 5 && tryparse(DateTime, newrow[2]) != nothing

newrow[2] = DateTime(newrow[2])

push!(df, newrow)

changeflag[1] = true

println("Added entry $newrow.")

end

elseif k == "latest" && v

println("The latest entry is $(df[end, :])")

elseif k == "latestfriend" && v

println(df[df.Relation .== "friend", :][end, :])

elseif k == "latestfamily" && v

println(df[df.Relation .== "family", :][end, :])

elseif k == "listbyage" && v

dobcol = df[:Birthdate]

age = map(x -> round((now() - DateTime(x)).value /(1000*3600*24*365.25), digits=1), dobcol)

df2 = deepcopy(df)

df2 = insert!(df, 1, age, :Age)

println(sort(df2, (:Age)))

end

end

if changeflag[1]

CSV.write(filename, df)

println("Changes written to file $filename.")

end

</lang>