JPH11143910A - Composite object development method and computer-readable recording medium - Google Patents

Abstract

(57) [Problem] To provide a technique suitable for handling an object-oriented database that stores data of a complicated structure in a complex object format on WWW. SOLUTION: Server side application code 112
Accesses the database 105 and returns the object identifier of the base object of the complex object format data that matches the database access request. HTM
The L template file 113 defines the type of the attribute value of the object to be actually returned to the user by describing an extension tag instructing the acquisition at a portion where the attribute value is embedded. The document development unit 109 accesses the base object pointed to by the returned object identifier and another object traceable by a pointer from the base object according to the extension tag in the template file 113, and acquires attribute values of the necessary objects. Generate an HTML document to be converted to a text format and returned to the user.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention stores and manages data having a complex structure, such as multimedia information, in the form of a complex object in a database, and manages the WWW (Wo).
related technologies on the server side required for a user to access such information from the Internet or an intranet typified by Internet (Information Rld Wide Web). More specifically, after acquiring a composite object from a database, the data is transmitted to a client. Related to a complex object expansion method when converting to a document format to be returned to the user at the same time.

[0002]

2. Description of the Related Art WWW is widely used for transmitting and providing information on the Internet. WWW
Is divided into a server that stores various information and a client that the user actually uses. H between them
TTP (HyperText Transfer Pr)
The protocol communicates using a protocol called “autocol” and a URL (Uniform Res) is transmitted from the client to the server.
A resource such as a document or an image uniquely identified by a source locator is requested, and an HTML (HyperText) is transmitted from the server to the client in response to the request.
Markup Language) Returns resources such as documents.

[0003] A user specifies a URL, displays an HTML document, and the like on a client through a WWW browser, and exchanges data with an HTML server running on the server. When accessing a database on the WWW, CGI (Common Gateway) is basically used.
y Interface) is often used. C
The GI can be used from most HTTP servers. When the user specifies a CGI script prepared in advance on the server by using a URL, the HTTP server dynamically starts the CGI script as a separate process,
Various services can be provided. C
By describing a search request or an update request for the database in the GI script, database access processing on the WWW can be realized.

However, since the return from the CGI script to the HTTP server must be in the form of an HTML document or the like, it is necessary to convert the data value in the database into a text format or embed a tag in an appropriate place. . If such processing is executed by a CGI script, it is not easy to create an application. Therefore, there is a WWW-DB cooperation system as a technology that can easily describe a database access process from the WWW. This WWW-DB cooperation system is also HT
Many use CGI in cooperation with TP server,
There is no need for the application developer to write the entire CGI script.
The creation method is such that it is only necessary to pay attention to the output to the ML document.

FIG. 7 shows an example of a conventional configuration of a WWW-DB cooperation system. In this system configuration example, an HTTP server 1002 and a database server 1006 operate in cooperation on a WWW server machine, and have a general configuration in which a relational database management system 1008 and the like are used as a back end.

In FIG. 7, a user uses a WWW browser 1001 running on a client to pass a URL and parameters (search conditions, etc.) to an HTTP server 1002 running on a server to make a request for database access. put out. The HTTP server 1002 transmits the gateway unit 1 to process the database access request.
The parameter is passed to 003, and the process is shifted to the database server 1006 that actually executes the database access process. The database server 1006 stores the URL of the plurality of application codes 1007 prepared in advance.
The database 100 through the database management system 1008 in accordance with the application code specified in
Access 9 The result is sent to the document generation unit 1004 through the gateway unit 1003.

A document generation unit 1004 generates an HTML document in order to return the result of the database access to the user. In the example of the system configuration shown in FIG. 7, the HTML template file 1005 has a generated HTML document in advance, and the document generation unit 1004 specifies the data value of the result received from the database server 1006 in the HTML template file 1005. An HTML document to be returned to the user is generated by converting the data into a text format and embedding it in the specified position. In addition,
A plurality of HTML template files 1005 are prepared, and which one is used is described in, for example, the application code 1007.

The document generation unit 1004 itself is in the database 1
Since 009 is not accessed, all the data to be embedded must be acquired when the application code 1007 is executed. H generated by the document generation unit 1004
The TML document is passed to the HTTP server 1002 as an output from the gateway unit 1003, and is returned to the WWW browser 1001 as it is.

There is also a system that stores complex data such as multimedia in a database and provides services on the WWW using an object-oriented database management system. However, the system configuration is shown in FIG.
It is almost the same as Therefore, when the data in the complex object format as illustrated in FIG. 2 is stored in the database, and the HTML document including the attribute values of various objects of the data matching the database access request is returned to the user, the necessary attributes are required. The application code 1007 is programmed so that all the values are acquired from the database, and the document generation unit 1004 embeds the acquired attribute values in the designated positions of the HTML template file 1005.

[0010]

Since data such as multimedia has a complicated data structure, a schema must be structurally defined in order to store such data in a relational database. Conventional WWW-D
In many cases, the B-linked system uses a relational database management system as a back-end database management system, so that complicated procedures are required to access such data. On the other hand, if an object-oriented database management system is used instead of a relational database management system, complex data structures can be stored in the database in the form of complex objects. Will be resolved. However, even if an object-oriented database management system is used as the back-end database management system of the WWW-DB cooperation system, the following problem remains if the processing procedure is equivalent to that of the conventional WWW-DB cooperation system. .

(1) It is not easy to create a database access processing part in application code. The reason is that it is necessary to program the application code to acquire from the database all the attribute values of the object to be returned to the user. (2) When the type and number of attribute values of an object to be returned to the user are changed, it is necessary to change both the application code and the HTML template file. The reason is that it is necessary to change the application code so as to obtain the changed attribute value and to change the HTML template file in order to determine the position where the obtained attribute value is embedded. (3) When the collection as shown in FIG. 2 is included in the complex object format data, the description of the HTML template file is not easy. The reason is that it is necessary to define, in the HTML template file, the positions where attribute values corresponding to the respective elements are to be embedded, by the number of elements included in the collection.

Accordingly, a first object of the present invention is to provide a technique suitable for handling an object-oriented database for storing data having a complicated structure in the form of a complex object on the WWW.

A second object of the present invention is to facilitate creation of a database access processing part in application code.

A third object of the present invention is to make it unnecessary to change the application code when changing the type and number of attribute values of an object to be returned to the user, and to cope with the change only by changing the HTML template file. Is to do.

A fourth object of the present invention is to make it possible to easily describe an HTML template file when a collection is included in complex object format data.

[0016]

SUMMARY OF THE INVENTION In order to achieve the above first to third objects, the present invention provides a database access request sent from a client side WWW browser via the Internet or an intranet to a server side HT.
The data is transmitted to the database server via the TP server, and in the database server, using the application code and the template file specified in the database access request, data matching the database access request is acquired from the object-oriented database to obtain a predetermined document. Convert to WWW format via HTTP server
In the WWW-DB cooperation system for returning to a browser, the application code is configured to access the database and return an object identifier of an object serving as a base point of complex object format data that matches a database access request from a user. And the template file specifies the type of attribute value of the object to be actually returned to the user.
A base object indicated by an object identifier returned from the application code and a base object indicated by the object identifier according to the content of the expansion tag in the template file, wherein the base tag has A document development unit that generates an HTML document to be returned to the user by accessing another object traceable by a pointer to obtain an attribute value of a required object, converting the attribute value into a text format, and embedding it in an output document. It is provided in a database server.

As described above, in the application code, the object identifier of the object serving as the base point of the complex object format data matching the database access request from the user is returned, and the attribute value of the object to be actually returned to the user is returned. Is defined in an HTML template file by describing an extension tag instructing the acquisition in a place where the document is embedded, and the document developing unit determines the type of the application code from the application code according to the content of the extension tag in the HTML template file. By accessing the base object pointed to by the returned object identifier and other objects traceable by the pointer from this base object, acquiring the attribute values of the required objects, converting them to text format and embedding them in the output document, To generate the HTML document to be returned to use person.

According to the present invention, to achieve the fourth object, a collection name is specified, a variable for substituting an element included in the specified collection is specified, and a user is actually designated by using the variable. In the HTML template file, a control syntax for a collection including a description specifying acquisition of an attribute value of an object to be returned is defined in an HTML template file, and the document developing unit performs, for each element included in the collection, according to the control syntax. Then, the element is assigned to a variable, the attribute value of the object to be actually returned to the user is obtained, converted to a text format, and embedded in the output document in order.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of a WWW-DB cooperation system to which the present invention is applied. WW of this example
The W-DB cooperation system includes a WWW browser 101 provided on the client side, an HTTP server 102 running on a WWW server machine, and an HTTP server 10
2, a database server 103 connected to the database server 103, a database management system 104 connected to the database server 103, and a database 105 connected to the database management system 104. In addition,
The WWW browser 101 and the HTTP server 102 are connected via the Internet or an intranet.

The database server 103 has a name table 110, a definition file 111, an application code 112, and an HTML template file 113, receives a database access request from a user, manages the name table 110, and manages the name table 110 in the database server. An application control unit 106 that controls the entire processing of the application, a definition file analysis unit 107 that analyzes a definition file 111 specified by a user and selects an application code 112 and an HTML template file 113, and an application code 112 that is described in the application code 112. A database access unit 108 that actually performs access processing to the database according to the logic or the like,
A document development unit 109 that generates an HTML document to be returned to the user based on the content described in the L template file 113.

Such a database server 103 can be realized by a computer constituting a server machine and a recording medium. The recording medium is a machine-readable recording medium such as a CD-ROM or a magnetic disk, and records an application code 112, a definition file 111, an HTML template file 113, and a program for a database server. The programs and data recorded here are read by a computer constituting the server machine, and by controlling the operation of the computer, the application control unit 106 including the name table 110 on the computer,
Definition file analysis unit 107, database access unit 1
08 and the document development unit 109 are realized.

The database 105 is an object-oriented database, and the database management system 104 is an object-oriented database management system. FIG. 2 shows an example of data stored in the database 105. The data in this example is product data that holds various information about the product in the form of a composite object, and includes one product object, an appearance object, an extension object, a specification object, a summary object, and a description object. It consists of feature objects and image objects, and one collection. The product object is an object serving as a base point of the product data. The product object is an appearance object holding various information related to the appearance of the product, a specification object holding various information related to the specification of the product, and the product object. An extension object that holds information about the extension of the product and a pointer to an outline object (an object identifier; the same applies hereinafter) about the outline of the product. The summary object holds a pointer to a description object and a collection that holds a description of the product, etc., and the collection holds a pointer to a feature object for each feature of the product.
It holds a pointer to an image object that holds an image showing its characteristics. The database 105 stores such complex object format product data,
It is stored for each different product, and it is possible to search for product data that matches desired conditions through the database management system 104.

The application code 112 is a code describing a process for the database 105, and is prepared for each predetermined process. One certain application code 112 executes a process such as searching for one piece of data that satisfies a certain condition from the database 105 by the logic of a method (function) described therein. At this time, the method returns a pointer of an object serving as a base point of the corresponding data obtained by the search or the like as a search result. For example, one application code 1 that searches for the product data shown in FIG.
In the method 12, for example, the product data below the product price specified by the given parameter is searched from the database 105 through the database management system 104, and the object serving as the base point of the product data, that is, the pointer of the product object is returned. Is programmed as The application code 11
The database access unit 108 performs actual access processing to the database according to the logic of the method described in 2.

The HTML template file 113 is
When the information of the product data obtained by executing the application code 112 is presented to the requesting user, it is a file that defines what kind of information is presented in what format. Document development unit 109
Generates an HTML document to be returned to the user by expanding the document with reference to the HTML template file 113. The HTML template file 113 is prepared for each type and format of information to be presented. FIG.
2 shows an example of the HTML template file 113 prepared for the product data in FIG.

The description of the HTML template file 113 in the example shown in FIG. 3 basically conforms to the format of the HTML document, and a notation and control syntax for embedding the data acquired from the database 105 are added by extending tags. I have. A tag including "@" is an extension tag. Of these, <{begindetail}> and <@endd
etail @> is an extension tag for designating, in the template, a location that requires database access. Also,
<@Product. name @>, <@ produc
t. image. name}>, <{product.
abstract. <text >> and the like are extension tags that specify the association between objects and access to the attribute values of the objects by dot notation. For example, <＄ p
product. abstract. text ＄>
"Abs pointed to by product object
The attribute value “text” of the struct object is acquired. ”

Further, from <@foreach...,
The description up to {done}> is a control syntax for expanding the collection (referred to as a foreach control syntax). The general form is <@foreach (variable name) in
(Collection name)}><{do}> (HTML text) ... In the form of <{done}>, for each element included in the collection specified by (collection name), the ) Indicates the meaning of processing (HTML text) within the range enclosed by <{do}> and <{done}>. Therefore, in the example of FIG. abstr
act. For each element included in the collection with the collection name features, the element is
assigned to a variable with a variable name of "re", an attribute value of title of the feature object, and a feature
The attribute value “name” of the image object pointed to by the “e” object is specified to be expanded.

The definition file 111 is stored in the database 10
5 is a file defining which method (function) of which application code 112 is to be used to access and which HTML template file 113 is to be used for data development. That is, the definition file 111 holds the following information. ○ Application code name ○ Method name (function name) ○ HTML template file name When a plurality of databases 105 exist, a database name is also specified, but in the following description, it is assumed that only one database 105 exists.

The definition file 111 includes an access type,
A plurality of data files are prepared according to the data development method and the like, and the user can specify any one of them by using a URL at the time of a database access request. The definition file analysis unit 107 selects one definition file 111 from a plurality of definition files 111 in accordance with the URL specified by the user, analyzes the definition file, and executes a method (function) in the application code to be executed. Select the HTML template file to use.

The name table 110 is a table managed by the application control unit 106 that controls the entire processing in the database server 103. The name table 110 holds various information necessary for processing a database access request requested by a user. Used. The typical one is
This is a pointer to an object serving as a base point of the complex object format data acquired from the database 105 by executing the application code 112. In addition, a parameter specified by the user at the time of the database access request, a method name to be executed in the application code 112, and the like are also stored.

Next, the operation of the WWW-DB cooperation system of the present embodiment configured as described above will be described.

When the user uses the database 105, the WWW browser 10 running on the client
HTTP server 1 running on the server using
In response to the HTTP server 1, a URL for designating a definition file and parameters necessary for database access are passed, and a database access request is issued.
02 until the HTTP document is returned.

When the HTTP server 102 receives the database access request, it passes the request to the database server 103 and controls the database server 103.
Transfer to

When the database server 103 receives the database access request and needs to access the data stored in the database 105, the database server 103 passes through the database management system 104.
, And finally generates an output document (HTML document) for returning to the HTTP server 102.
Output to the server 102.

The HTTP server 102 outputs this HTTP document to the WWW browser 101, and the WWW browser 10
1 displays this HTTP document on a screen and presents it to the user.

The schematic operation of this embodiment is as described above.
Next, the operation of the database server 103 which is a main part of the WWW-DB cooperation system of the present embodiment will be described in detail.

FIG. 4 is a diagram showing the relation between the data used by the database server 103 and the database server 10.
FIG. 5 is a flowchart for explaining the operation of FIG. 3, and FIG. 5 is a flowchart showing the flow of the entire processing of the database server 103.

The application control unit 106 of the database server 103 sends the URL from the HTTP server 102 to the URL.
Is passed, the URL is passed to the definition file analysis unit 107. The definition file analysis unit 107 analyzes the definition file 111 specified by the URL, and
The application code name, method name, and HTML template file name described in No. 1 are acquired and passed to the application control unit 106 (501). Next, the application control unit 106 sets the acquired method name in the name table 110 (502). In the example of FIG. 4, a method named “query” has its type, type,
Set with a pointer to

Next, the application control unit 106
Parameter passed with RL to name table 1
It is set to 10 (503). In the example of FIG. 4, the actual character string of the parameter having the name “para” is stored in an area of the text data 403 different from the name table 110, and the name, type, type, and text data 403 are stored in the name table 110. The pointer to is set.

Next, the application control unit 106 starts the execution of the method set in the name table 110 in the application code 112 of the acquired application code name. If database access is required during the execution of this method, the database access unit 108 causes the database management system 104
The database 105 is accessed through the. Parameters required for database access are referred to from the name table 110 via the application control unit 106 as appropriate. Then, the application control unit 106
Sets the result data obtained by executing the method in the name table 110 (504). As previously mentioned,
A method in the application code 112 returns a pointer of an object serving as a base point of the corresponding data obtained by searching the database 105 as a search result. That is, in a certain method in the application code 112 which searches for the product data shown in FIG. 2, for example, the product data below the product price specified by the given parameter is searched from the database 105 through the database management system 104. And returns a pointer to a product object which is an object serving as a base point of the product data. In the name table 110, a pointer to an object serving as a base point of such product data is set as result data. In the example of FIG. 4, a pointer to an object named “product” is set in the name table 110 together with the attribute and the type.

The result data and the like set in the name table 110 are exported before being set in the name table 110 so that they can be referred to from outside the application code 112. Since the exported variables can be externally referenced, the database 1
05 can be registered in an entry of the name table 110 as a pointer to the object in the name 05.

When the setting of the result data in the name table 110 is completed, the application control unit 106 transfers the HTML template file name acquired in step 501 to the document development unit 109. Document development unit 1
09 is the H to be returned to the HTTP server 102 according to the contents of the HTML template file with the passed name.
A TML document is generated (505). When it is necessary to access the composite object of the database 105 when generating the HTML document, the document expanding unit 109 refers to the result data of the name table 110 through the application control unit 106, acquires a pointer of the base object of the result data, The base object in the database 105 and other objects that can be traced by the pointer from the base object are accessed through the database access unit 108. In the example of FIG. 4, the <@product. When processing the description of name @>, the name table 110 is used in the product.
, A pointer to the product object is obtained, and the attribute value “name” of the product object is obtained from the database 105 using the obtained pointer.

FIG. 6 is a flowchart showing a processing example of the document developing unit 109. Hereinafter, the operation of the document developing unit 109 will be described with reference to the flowchart of FIG. Note that HT
<$ Begind in the ML template file 113
Since the description other than the part enclosed by <etail} and <{endtail}> is output as it is to the output document, in FIG. 6, <{begindetail}> and <＄
Only processing for the portion enclosed by endtail @> is shown.

The document developing unit 109 sets the <@beginde
When detecting {tail}, first, the counter C of foreach is set to 0 (601), and <{begindetail}> in the HTML template file 113 is set.
To <{endtail}> are set as the input document C (C is the value of the counter C of foreach. Therefore, the input document 1 is initially set), and attention is paid to the input document C (602). Then, reading of the token is started in order from the top of the input document C (603). Here, the token is a lexical unit described in the HTML template file 113, and is expressed as <H2>, <@prod
oct. name @> etc. are each one token.

When the input document C has a token (603)
YES), it is determined whether it is a tag (604), and if it is not a tag, the token (fixed text or the like) is added to the output document (611), and the process returns to step 603 to return the next token from the input document C. Read.

If the read token is a tag (60
4 is YES), and it is determined whether it is an extension tag (60).
5) If the tag is not an extension tag, the token (normal tag) is added to the output document (611), and the process returns to step 603 to read the next token from the input document C.

If the read token is an extension tag (YES in 605), it is determined whether it is a control syntax (60).
6) Since the attribute value is accessed from the object variable name if it is not the control syntax, the attribute value is obtained by following the dot expression, converted into a text format, and added to the output document (612). Then, the process returns to step 603 to read the next token from the input document C.

If the read extension tag is a control syntax (YES in 606), it is determined whether the extension tag is foreach (607), and if not, a process corresponding to the corresponding control syntax is executed (613). ), Step 603
And reads the next token from the input document C. fo
Although an if sentence or the like can be considered as a control syntax other than the reach, the description is omitted because it is not directly related to the present invention.

If the read extension tag is "foreach", the counter C of "foreach" is incremented (608), and the first element of the collection of the collection name immediately after "foreach" is put in the variable of the variable name following "foreach" (609). ), Immediately after <＄ do ＄> and <＄ d
one @>, the input document C
(Accordingly, the input document 1 is set next to the input document 2), and the input document C is focused (610). Then, returning to step 603, the above-described processing is repeated for the input document C. The processing for the input document C is <{do}
> And <{done}> from the first token to the last token of the text portion. And, after processing the last token in the text part,
In step 603, it is determined that there is no next token, and the flow advances to step 614.

In step 614, it is determined whether the value of the foreach counter is greater than zero. If the value is larger than 0 (YES in 614), since the inside of the foreach control syntax is being processed, it is checked whether or not the next element exists in the collection specified by the foreach control syntax being processed (61).
6) If there is, the element is put into a variable designated by the foreach control syntax (617), and the next read destination token is reset to the first token of the currently focused input document C (618), and step 603. And the above-described processing is repeated for the input document C.

On the other hand, if there is no next element in the collection specified by the foreach control syntax being processed (616)
NO), the counter C of the foreach is decremented (619), and the focus is shifted to the input document C (therefore, the input document 2 next to the input document 2) (620), and step 60
3, the above-described processing is repeated for the input document C.

In step 614, fore
If the counter of ach is not greater than 0, <＄ beg
That is, the processing for the part enclosed by <indetail} and <{endtail}> has been completed.
Thereafter, the output document is returned to the HTTP server 102 (6
15), end the processing in FIG.

The operation of the document developing unit 109 will be described again with reference to the HTML template file of FIG. 3 as an example.

The counter C of “foreach” is set to 0 (601), and from <{begindetail}> in the HTML template file 113, <＄ enddet
The description part up to aile @> is set as the input document 1 (602), and reading of tokens is started in order from the beginning (603). The first token <H2> is processed in step 611 and added to the output document. The next token <$ product. name @> is equal to step 612
, The attribute value “name” of the product object is acquired from the database 105 and added to the output document. At this time, pr is read from the name table 110 using the object name product as a base as a key.
The product entry of the database 105 is accessed using the pointer to the product object set therein, and the attribute value of the name is acquired. Thereafter, each token up to <UL> is similarly processed.

Token <$ foreach feature
re in product. abstract. fe
at the same time, the counter C of the foreach is incremented to 1 in step 608, and then the collection name is changed to product.product in step 609. abstract. feature
The first element of the collection that is res is the variable fe
ature. Then, the next step 609
<LI><@ feature, assuming that the variable feature is the first element of the collection
re. title ＄><IMG SRC = “<＄ fea
cure. image. input document 1 is processed. In the processing of this input document 1, first, the token <LI> is processed in step 611, and the next tokens <{feature.title}> and <IMG S
RC = ”<{feature.image.name}
>”> Are processed in step 612.

The last token of the input document 1 <IMGS
RC = ”<{feature.image.name}
At the time when >>> is processed, fo is determined in step 614.
It is determined that the counter C of “reach” is greater than 0, and in step 616, the collection product. a
bstruct. It is determined that the feature has the next element, the element is set to a variable feature (617), the next read destination token is reset to the first token <LI> of the input document 1, and the input document 1 is again set.
Is processed. This processing assumes that the variable feature is the second element of the collection and <L
I><@ feature. title @><IMG S
RC = “{feature.image.name}
>> input document 1. The following is a collection product.abstract.feature
Similar processing is repeated until the last element of s.

When the processing is repeated up to the last element of the collection, the counter C of foreach is decremented to 0 in step 619, and the input document 0
Attention is paid to and processing is continued. Therefore, the tokens after </ UL> are processed. When the processing is completed up to the last token </ CENTER> of the input document 0, it is determined in step 603 that there is no next token,
Since the counter C of foreach is 0, step 61
Proceed to 5 to return the output document and end the process.

Since the HTML template file shown in FIG. 3 has only one foreach control syntax, the counter C of foreach takes only values 0 and 1, but the foreach control syntax is nested. Takes a value of 2 or more. The HTM shown in FIG.
The L template file is an example on the assumption that only one result data is returned from the application code. However, when the application code returns a plurality of result data, the following may be performed. First, in the application code, a collection in which individual result data (in the example, a pointer to a product object) is stored in each element is generated, and a pointer of the collection is returned as the result data. On the other hand, in the HTML template file, it is defined that each element of the collection is sequentially taken out and the processing illustrated in FIG. 3 is repeated for each element. As a result, the result data for all the product data can be returned at a time, and an output document can be generated collectively.

[0059]

As described above, according to the present invention, the following effects can be obtained.

The creation of the database access processing portion in the application code is facilitated. The reason is that the application code should be programmed so as to return the object identifier of the object that is the base point of the complex object format data that matches the database access request from the user, and the object that should actually be returned to the user This is because the process of accessing the attribute value is performed by a document development unit common to all application codes.

When the type and number of attribute values of the object to be returned to the user are changed, the change can be dealt with only by changing the template file, and there is no need to change the application code. The reason is that the application code only returns the object identifier of the base object of the complex object format data that matches the database access request from the user, and the type of the attribute value of the object that should actually be returned to the user is This is because the document developing unit performs the processing based on the description of the template file.

The description of the HTML template file when the collection is included in the complex object format data is simplified. The reason is that we have introduced a new control syntax for collections.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a WWW-DB cooperation system to which the present invention is applied.

FIG. 2 is a diagram showing an example of complex object format data stored in a database.

FIG. 3 is a diagram illustrating a description example of an HTML template file.

FIG. 4 is a diagram for explaining the operation of the database server focusing on the relationship between data used by the database server;

FIG. 5 is a flowchart showing the overall processing flow of the database server.

FIG. 6 is a flowchart illustrating a processing example of a document developing unit.

FIG. 7 is a block diagram of a conventional WWW-DB cooperation system.

[Explanation of symbols]

 101 WWW browser 102 HTTP server 103 Database server 104 Database management system 105 Database 106 Application control unit 107 Definition file analysis unit 108 Database access unit 109 Document development unit 110 Name table 111 Definition file 112 … Application code 113… HTML template file

Claims (5)

[Claims] 1. A database access request transmitted from a client-side WWW browser via the Internet or an intranet is transmitted to a database server via a server-side HTTP server, and the application code specified by the database access request is transmitted to the database server. In a WWW-DB cooperation system for acquiring data matching a database access request from an object-oriented database using a template file, converting the data into a predetermined document format, and returning the document format to a WWW browser via an HTTP server, the application code Is the object identifier of the object serving as the base point of the complex object format data that matches the database access request from the user by accessing the database. The template file is configured to return the type of the attribute value of the object to be actually returned to the user, and an extension tag for instructing acquisition of the attribute value at a location where the attribute value is embedded. And, according to the content of the extension tag in the template file, access the base object pointed to by the object identifier returned from the application code and another object traceable by a pointer from the base object to obtain the attribute value of the required object And
A complex object development method, wherein the database server is provided with a document development unit that generates an HTML document to be returned to a user by converting the data into a text format and embedding it in an output document. 2. The template file further includes a specification of a collection name, a specification of a variable for substituting an element included in the specified collection, and an attribute of an object to be actually returned to the user using the variable. A control syntax for a collection including a description specifying acquisition of a value has a configuration defined at a location where the attribute value is embedded, and the document expansion unit performs, for each element included in the collection, according to the control syntax. 2. The composite according to claim 1, wherein the element is assigned to a variable, the attribute value of the object to be actually returned to the user is acquired, converted into a text format, and embedded in the output document in order. Object expansion method. 3. The apparatus according to claim 2, further comprising a name table for holding a name of an object serving as a base point of said complex object format data obtained by accessing said database by said application code and an object identifier thereof. Complex object expansion method. 4. A database access request sent from a client-side WWW browser via the Internet or an intranet is transmitted to a database server via a server-side HTTP server, and an application code specified by the database access request in the database server is transmitted to the database server. In a WWW-DB cooperation system, a template file is used to acquire data matching a database access request from an object-oriented database, convert the data into a predetermined document format, and return it to a WWW browser via an HTTP server. An application configured to access and return the object identifier of the object that is the base of the complex object format data that matches the database access request from the user. Application file, a template file having a configuration in which the type of the attribute value of the object to be actually returned to the user and an extension tag for instructing the acquisition thereof in a portion where the object is embedded, and a computer configuring the database server, According to the content of the extension tag in the template file,
By accessing the base object pointed to by the object identifier returned from the application code and another object traceable by the pointer from the base object, acquiring the attribute value of the required object, converting the object value into a text format and embedding it in the output document. A computer-readable recording medium on which a program that functions as a document expanding unit that generates an HTML document to be returned to a user is recorded. 5. In the construction of an information service / information system utilizing Internet / intranet technology,
Data such as multimedia handled in the system is stored in a database on the server machine in a state structured by complex objects, and when a user requests database access from a client machine, the requirements Means for controlling what kind of processing is performed according to, and means for accessing a database based on application code provided in advance, and acquiring a complex object required by the user,
A composite object development method characterized by comprising means for converting necessary data in an obtained composite object into a text format and embedding it in an output document in order to generate an output document to be returned to a user.