Simple database: Difference between revisions

{{task|Data Structures}}

 

Write a simple tool to track a small set of data.

The entered data should be stored in a structured format and saved to disk.

 

 

You should track the following details:

* Other optional fields

 

The command should support the following [[Command-line arguments]] to run:

* Add a new entry

* Print all entries sorted by a date

 

The category may be realized as a tag or as structure (by making all entries in that category subitems)

 

 

 

=={{header|C}}==

"Treasure Beach","Argus","Jemky","09-22-1999","Lancast"

 

#include <stdlib.h> /* malloc */

#include <string.h> /* strlen */

sort_by(last_name);

sort_by(title);

/* main */

int main (int argc, char **argv) {

TRY (f=fopen(DB,"a+"));

if (argc<2) {

"-a Print all entries sorted by author.\n",argv[0]);

fclose (f);

printf ("-d Print all entries sorted by date.\n");

dblist = dao (READ,f,&db,NULL);

dao (PRINT,f,dblist,NULL);

dao (DESTROY,f,dblist,NULL);

qsort (pdb,i,sizeof in_db,sortby);

pdb[i-1]->next=NULL;

pdb[i-1]->next=pdb[i];

}

}

else return ((*p1)->date > (*p2)->date);

 

=={{header|COBOL}}==

This is a souped-up version of the task from [[Take notes on the command line]]. It stores the current date, a tag, a title and a note as an entry in a file. The database produced is not particularly human-readable or easy to modify, but it is in a well-structured format.

{{works with|OpenCOBOL}}

PROGRAM-ID. simple-database.

 

"The title should be specified as shown for -c."

DISPLAY " -t - Show all the entries sorted by tag."

 

Sample session:

 

=={{header|Common Lisp}}==

 

 

 

 

 

 

 

 

 

(multiple-value-bind

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

=={{header|D}}==

std.file, std.csv, std.datetime;

 

return printUsage();

auto db = load();

const cat = (item.length == 4) ? item[3] : "none";

db ~= Item(item[2], date, cat);

default: printUsage(); break;

}

{{out}}

<pre>C:\>simdb add item1 cat1

 

C:\>simdb latest

 

C:\>simdb latest cat4

 

C:\>simdb all

 

C:\>simdb add

For instance: add "some item name" "some category name"</pre>

File:

 

=={{header|Erlang}}==

#! /usr/bin/env escript

 

io:fwrite( "Data stored in ~p~n", [file()] ),

init:stop().

Command line session started with these file contents as database:

<pre>

2013-9-16 comic gustaf

</pre>

 

=={{header|Forth}}==

 

Code:

' noop is bootmessage

 

cr cr ;

current !

 

=={{header|Go}}==

 

import (

fmt.Println(err)

}

=={{header|Haskell}}==

 

Item {description = "La traviata", category = ["Classical"], date = Date 2012 10 19, optional = ["Giuseppe Verdi","1853"]}

 

import Data.List (sortBy, nub)

import System.Environment (getArgs, getProgName)

mapM_ (hPutStrLn hw . show) v

hClose hw

 

=={{header|J}}==

J comes with a sql database, jdb. Jdb's columns are memory mapped files with header information. These won't meet the human readable data file requirement. Hence, this program:

 

Commands:

 

 

exit 0

Assume the j code is stored in file s . These bash commands, stored in file input , create a database using add .

$D add name expression algebraic rank valence example explanation

$D add atop 'x f@g y' 'f(g(x,y))' 'rank of g' dyad '>@{.' '(lisp) open the car'

$D add 'many more!'

Now we look up data from the bash command line.

$ . input # source the input

$ echo $D

'2012-02-08:23:45:06.515';'atop';'x f@g y';'f(g(x,y))';'rank of g';'dyad';'>@{.';'(lisp) open the car'

'2012-02-08:23:45:06.539';'many more!'

 

=={{header|PicoLisp}}==

The '[http://software-lab.de/doc/refR.html#rc rc]' resource file handling function is used typically for such tasks. It also takes care of proper locking and protection.

 

(de usage ()

(T (usage)) ) )

 

Test:

<pre>$ sdb CDs add "Title 1" "Category 1" 2011-11-13

=={{header|Pike}}==

{{trans|Common Lisp}} (simplified)

 

mapping make_episode(string series, string title, string episode, array date)

else

watch_list(db);

 

=={{header|Python}}==

 

'''\

now = datetime.datetime.utcnow()

args._date = now.isoformat()

 

;Sample session (Unix):

 

=={{header|Racket}}==

#!/usr/bin/env racket

#lang racket

(for-each (compose1 show last/cat) (remove-duplicates (map cadr data)))]

[else (error 'sdb "bad printout mode")])])

 

Sample run:

[cds] Some-CD; 2013-01-03

</pre>

 

=={{header|Ruby}}==

require 'json'

require 'securerandom'

end

 

 

Sample session

</pre>

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

=={{header|Tcl}}==

The format used is that of a Tcl dictionary, where each entry uses the title as a key and the remaining information (category, date and miscellaneous metadata) is the value associated with it. The only variation from the standard internal format is that entries are separated by newlines instead of spaces; this is still a legal value, but is a non-canonical.

package require Tcl 8.6

namespace eval udb {

}

 

Sample session:

wrong # args: should be "udb.tcl dbfile subcommand ?args...?"

bash$ udb.tcl db ?

Title: Title 3

Category: bar

 

=={{header|ToffeeScript}}==

 

prog = require 'commander'

printFormatted entry

 

 

=={{header|UNIX Shell}}==

This format is guaranteed to be human readable: if you can type it, you can read it.

 

db_create() {

show_help

;;

Create DB `CDs'

$ sdb add CDs Bookends

$ sdb drop CDs

Delete DB `CDs'