Using NIKA DBMS in internet
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The system has been made by means of NIKA DBMS and http 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
http 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 hierarchy.
- 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.
- 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.
The common view of HTML-document made by the http server
Data base title
Path in data base
Home Pag -> |
NIKA_ROOT -> |
Field1 -> |
. . . |
Fieldn -> |
{
- Fieldn1 = Value1
- Fieldn2 = Value2
- . . .
- Fieldnk = Valuek
}
{
- Fieldnk+1 ->
- Fieldnk+2 ->
- . . .
- Fieldnk+m ->
}
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{
}
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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.
Several variants of current level
- 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 -> |
Field(n+1)key |
Field(n+1)1 |
Field(n+1)2 |
. . . |
Field(n+1)m |
Value(n+1)key1 -> |
Value(n+1)11 |
Value(n+1)21 |
. . . |
Value(n+1)m1 |
Value(n+1)key2 -> |
Value(n+1)12 |
Value[(n+1)22 |
. . . |
Value(n+1)m2 |
. . . |
Value(n+1)keyk -> |
Value(n+1)1k |
Value(n+1)2k |
. . . |
Value(n+1)mk |
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Where -> means a hypertext link. The terminal elements in
the table are the elements from the next level of the data base hierarchy.
- 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.
- Level scale.
The current level look as scale of elements. Each element prints in
brackets.
- 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.
Request system
Containes three levels for the request.
- Hierarchy list of NIKA data base objects.
- Input form of NIKA data base vertices for selected object.
- Result tree for given request.
Notes
- When the current level contains only one reference
(and terminal fields are absent), the http server automatically passes
onto the next level (under this field) and makes an HTML-document of that
level.
- When the current level contains more than
given number of fields the HTML-document has the refernce to the next
portion of fields.
- As a rule, level scale combines with table or array.
- If the number of elements in current level is very
big, then it divided by several 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