JPH05265835A - System for view-defining/referring in object base system - Google Patents

Abstract

PURPOSE:To once perform all the required inspections only at the time of defining view by eliminating the inspection concerning whether an object belongs to a view class or not and whether an instance parameter/method can be referred to or not in the case of referring to the object while executing a program. CONSTITUTION:When a source program 100 a program translation part 101 translates, a view-definition sentence is processed, connecting it to a view definition analysis part 102, view definition inspection part 103 and view class generation part 104. In the process of this processing, the source program is connected to a data base managing part 105 for investigating whether the view definition is correct or not, and an executing form program 107 is finally outputted. When the procedure of generating view instance is performed at the time of executing this executing form program 107, a generating request is outputted to a data base managing part 105. When the object is referred to at the time of execution, it is connected to the data base managing part 105, and the object is read/ written from a data base 106.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a view definition / reference method by which a user can virtually define / reference an object already existing in a computer system with an object of another structure.

[0002]

2. Description of the Related Art In a conventional object-oriented programming system, database system, or relational database system, when data structure information (for example, variable name, variable type, size, etc.) is defined, its definition is defined. Information is stored in class objects (also called data dictionaries). When creating the actual object (ie the actual data), use the appropriate class
The area is secured by the creation operator by specifying the object. That is, the object (instance,
In some cases, some areas are also called instance variables (also called fields or attributes). In addition, a procedure (also called a method) for operating an object that belongs to the class
Exists. Objects and class objects have object numbers (or keys, addresses) that uniquely identify themselves. This number is assigned by the system.

In such an object-oriented system, when it is desired to see an already existing (defined) class as a class having a slightly different structure, for example,
If you want to be able to refer to only some of the instance variables of a class that has already been defined, or to combine several classes so that they can be referred to as one class, create a new class for that and create an object for that A new (or associate)
There is a need. For example, assume that an employee class that defines the structure for employees and its object (employee data) already exist. If you are a general user,
If you want to provide a class with the variables related to salaries in the "employee" class, you must create (or associate) an "employee for public" class and an object for it. Such a virtual class is called a view class.

The view class is described in the document [kimura9
1] kimura, Y .; and K. Tsuruok
a "A View Class Mechanism
forObject-Oriented Databa
se Systems, "Proc. Intl.
Symp. on Database Systems
for Advanced Application
s (DASFAA '91) Apr 1991. Holds the classes that make up the view, the referenceable instance variables and methods, the additional methods, and the object creation conditions, as discussed in. When referencing an object, first find out if it belongs to the view class. If it belongs to the view class, check whether the requested reference is contained in the referenceable variable / method registered in the view class. If it cannot be referenced, an error is returned. In this way, when the view is provided, it is necessary to check whether the object belongs to the view class and check the reference of the instance variable / method when referencing the object.

[0005]

In the conventional view definition / reference method described above, whenever an object is referenced during the execution of a program, it is always checked whether it belongs to a view class and an instance variable. There is a drawback in that the execution speed of the program is significantly reduced because it involves the checking of the referenceability of the method.

It is an object of the present invention to eliminate view checking during the execution of a program and to perform all necessary checks only once when defining a view, thus defining a view definition in an object-based system which improves the above drawbacks. To provide a reference method.

[0007]

A view definition / reference method in an object-based system according to the present invention comprises means for analyzing / inspecting whether a view definition is correct when translating the view definition, and a database management unit at the time of the inspection. To the view instance, a means to generate a view class corresponding to the view definition when an OK notification is received in response to the inquiry, and a view instance from the executable program in the same manner as a normal object It is characterized by including the means that can.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, the object grouping method is the program translation unit 101 and the view definition analysis unit 10.
2, a view definition inspection unit 103, a view class generation unit 104, a database management unit 105, a database 106, an executable program 107, and a view instance generation unit 108.

When translating the source program, the program translation unit 101 is connected to the view definition analysis unit 102, the view definition inspection unit 103, and the view class generation unit to process the view definition statement. In the process of this processing, the database management unit 105 is connected to check whether or not the view definition is correctly performed. Database management unit 1
Reference numeral 05 controls reading and writing of the database 106. The program translation unit 101 finally outputs the executable program 107. When this execution form program 107 is executed, if there is a view instance generation procedure, the view instance generation unit 108 is connected and a generation request is issued to the database management unit 105. When an object is referenced in the executable program, the database management unit 105 is connected to read or write the object from the database 106.

FIG. 2 is a flow chart for explaining the grouping operation when the user issues a grouping request, and FIG. 3 is a data structure diagram for use in the present invention. Less than,
A description will be given according to the flowchart of FIG. 2 with reference to FIGS.

First, a translation request is issued to the program translation unit 101 for the source program 100 for view definition / reference. Upon receiving this request, the program translation unit 101
Check if the source program 100 is empty (Step 2
00), if not empty, read the sentence (step 201). When this sentence is a sentence other than the view definition, the sentence is translated and an executable code is output (step 213). If this statement is a view definition statement (step 202), an analysis request is issued to the view definition analysis section 102 (step 203). In the view definition analysis unit 102, when the syntax of the view definition is defined correctly (step 204), the reference class, reference instance variable, reference method, additional method that the view refers to or limits the reference from the view definition statement. ， Extract the view instance generation method,
Is registered in the referable information table 300 (step 2)
05). If the definition is incorrect, control is returned to the program translation unit 101. Next, the view definition analysis unit 102 issues an inspection request to the view definition inspection unit 103 in order to inspect whether this definition information is correct (step 20).
6). At this time, the information of the referable information table 300 is also passed. In the view definition inspection unit 103, information (reference class, reference instance variable, reference method, additional method, view instance generation method) stored in the referenceable information table 300 is stored in the database 106.
It is checked whether it is the same as that already registered in (step 207). Therefore, the database management unit 1
Inquire to 05 together with each information. If any of the information does not match the information in the database 106,
The database management unit 105 notifies the view definition inspecting unit 103 that there is an error, and the view definition inspecting unit 103 having received the notification further notifies the program translating unit 101 of the error (step 208).

If the view definition inspecting unit 103 receives an OK notification from the database managing unit 105, it issues a control request to the view class generating unit 104 to generate a view class (step 209). The view class generation unit 104 generates a view class, sets the information of the referenceable information table 300 in the view class (step 210), and stores this class in the database 106.
To the database management unit 105 (step 211). When the database 106 is successfully stored, the control is returned to the program translation unit 101 (step 212). When all the translations are completed, the program translation unit 101 executes the executable programs 107 for all the programs.
Is output.

If the user activates this executable program 107 and there is a view instance generation request in this program, the view instance generation unit 10
Call 8. The view instance generation unit 108 requests the database management unit 105 to execute the view generation procedure of the specified view class. As a result of this execution, the view class and its instance are associated.

When an object is referenced during execution of the program, the executable program 107 requests the database management unit 105 to reference the object. At this time, it is not checked whether the object belongs to the view. Because this executable program 10
This is because the correctness of the reference operation 7 is guaranteed in the translation process of the source program 100 by the program translation unit 101.

[0016]

As described above, according to the present invention, when an object is referenced during program execution, it is checked whether the object belongs to a view class and whether the instance variable / method can be referenced. There is an effect that software for defining and referencing a view can be executed at a high speed by eliminating the check of 1. and performing all necessary checks only once when defining a view.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a grouping operation when a user issues a grouping request.

FIG. 3 is a data structure diagram for use in the present invention.

[Description of Reference Signs] 100 source program 101 program translation unit 102 view definition analysis unit 103 view definition inspection unit 104 view class generation unit 105 database management unit 106 database 107 execution format program 108 view instance generation unit

Claims (1)

[Claims] 1. When translating a view definition, means for analyzing / inspecting whether the view definition is correct, means for making an inquiry to a database management unit at the time of the inspection, and receiving an OK notification for the inquiry. , A view definition in an object-based system, comprising means for generating a view class corresponding to the view definition, and means for referring to an instance of the view from an executable program in the same manner as a normal object. Reference method.