The system has been made by means of NIKA DBMS and web-server (a program for using NIKA DBMS in Internet). Data base has a tree-like structure. Each time client acceses the site, he gets the HTML-document using that web-server. The HTML-document contains the path in data base and the current level in data base.

• The data base path is a table which contains several fields - vertices of DB. The first is Home Page. The second is NIKA_ROOT (the root of data base) and so on (see the common view). This fields are hypertext links. More left fields corresponds to higher levels of data base hyerarchy.

• The current level is an unodered list contaning several fields. This fields can be either hypertext links (unterminal vertices) or simply text (terminal vertices) (see the common view).

• To move down the data base tree select the field (which is hypertext link) in unodered list. As a rule, the selected field will appear in a table (titled "the data base path") on a next page at the end of the table (see example 1).

• To move up the data base tree select the field in the table. For example when you select the field Home Page you get the Home Page, when you select the field NIKA_ROOT you get HTML-document containing the root level of data base; and when you select another field in the table you get HTML-document with a level corresponding to the selected field. As a rule, fields, which are more right than the selected field in the table, disappear (see example 2).

The common view of HTML-document made by the web-server

Where -> means a hypertext link; Field1,Field2,...,Fieldn are vertices in the data base path; Fieldn1,Fieldn2,...,Fieldnk - terminal vertices, and Fieldnk+1,Fieldnk+2,...,Fieldnk+m - unterminal vertices. In the table Select font you can choose an appropriate code page to make documents readable in russian.

Several variants of current level

1. Table.
   The current level can contains the table, in which the first col. ( and may be the second ) contains elements with hypertext referencies. The other colums are terminal fields. In this case the html-document has the view as follows.

   ---

   Data base title Path in data base Home Page-> NIKA_ROOT-> Field1 -> . . . Fieldn -> Fieldn Field(n+1)1 Field(n+1)2 . . . Field(n+1)m Valuen1 -> Value[(n+1)1]1 Value[(n+1)2]1 . . . Value[(n+1)m]1 Valuen2 -> Value[(n+1)1]2 Value[(n+1)2]2 . . . Value[(n+1)m]2 . . . Valuenk -> Value[(n+1)1]k Value[(n+1)2]k . . . Value[(n+1)m]k Select font: DOS-> Windows-> KOI8-> OS2-> LAT->

   ---

   Where -> means a hypertext link. The terminal elements in the table are the elements from the next level of the data base hierarchy (see example 5).

2. Array.
   See the common view of HTML-document. In this case the current level of common view can be appears l-times (l=1,2,3,4,...) and in each case the reference fields, terminal fields have the particular values (see example 6).

3. Level scale.
   The current level look as scale of elements. Each element prints in brackets.

4. Alphabetical index.
   The current level is alphabet. Each letter is reference to the group of elements beggining from this letter. Near the letter print the first element of the group. (see example 7).

Request system

Notes

1. When the current level contains only one reference (and terminal fields are absent), the web-server automatically passes onto the next level (under this field) and makes an HTML-document of that level (see example 3).

2. When the current level contains more than 100 fields the HTML-document of that has the following structure. At the begining of the current level the first hundred fields are placed, and then fields are printed by step of 100, i.e. Field1,Field2,...,Field100,Field101,Field201,Field301,Field401,.... Besides, fields Field101,Field201, Field301,Field401,... are printed in bold and having more spaces between rows. If you select the field from Field1 to Field100, you get the HTML-document with level under the selected field. If you select the field from Field101,Field201,Field301,Field401,..., for example Field201, you get the HTML-document with Field1,Field101,Field201,Field202,...,Field300,Field301,Field401,...
   and so on (see example 4).

3. As a rule, level scale combines with table or array.

4. If the number of elements in current level is very big, then it divided by severel seperate html-documents. Each html-document (except the last) containes the reference to the next html-document. The reference prints at the end of html-document:

   NEXT ->

   (see example 8).

Examples