JPH07141237A - Data base access control unit - Google Patents

Abstract

PURPOSE:To enable plural programs to share data by constituting a data base by introducing a data base management system for plural files which the program group accesses. CONSTITUTION:This data base access control unit consists of a conversion information file 5 which stores the order of conversion of a file access instruction into a data base access instruction, an SQL conversion/control processing part 6 which performs the conversion of the access instruction and control over information by using the conversion information file 5, a data base constitution object file management table 3 in which files put in the data base among files that a current program accesses are registered, and a file management system part 2 of a computer operating system to which a routine for linkage with the SQL conversion/control processing part 6 by using the data base constitution object file management table 3 when the corresponding file is not found on the computer at the time of file access by the current program is added.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database access control device for a computer system having a program group for accessing a plurality of files.

[0002]

2. Description of the Related Art For a plurality of files accessed by a program group in a computer, a database management system has been introduced to create a database, and data sharing between these multiple programs has hitherto been performed by multiple businesses. It is possible to obtain centralized management of the same information that has been referred / updated, which is a great advantage.

[0003]

However, in order to realize a database, it is necessary to radically reconstruct the program group that accessed the data on the file or reconstruct the program group, which is a huge remodeling. / Test work was occurring. The present invention has been made in view of the above circumstances, and when introducing a database management system to a current system that does not use a database, the current program is converted into a database without modification, or with a small modification amount, and It is an object of the present invention to provide a database access control device capable of realizing equivalent functions.

[0004]

A database access control apparatus according to a first aspect of the present invention has a group of programs for accessing a plurality of files, and manages a database in which data of the plurality of files is fetched. In a computer system having a system, a conversion information file that stores a procedure for converting a file access command into a database access command, and an SQL conversion / control processing unit that performs conversion of an access command and control of information using the conversion information file, Among the files accessed by the current program, the database conversion target file management table for registering the database-converted files, and the database conversion target file management table when the corresponding file cannot be found on the computer when accessing the current program file It was composed of a file management system of the computer operating system by adding a routine to achieve integration with SQL conversion / control processing unit described above with reference to tables.

The database access control device according to [Claim 2] of the present invention is [Claim 1] wherein the file I / O of the current program designed / manufactured to access the file in the current program group. Command section,
The database I / O command unit is modified to a simple command that can be recognized by the SQL conversion / control processing unit.

In the database access control apparatus according to [Claim 3] of the present invention, the database in which the current program group and the file I / O command part of the current program are changed to simple commands that can be recognized by the SQL conversion / control processing part. I / O
In a control device including a current program group including a command section and an SQL conversion / control processing section having a conversion information file, an SQL conversion / control processing section is provided between the two to perform control processing.

[0007]

In the database access control apparatus according to the first aspect of the present invention, when the current program makes a file access request, the file management system unit of the OS which has received the request makes the corresponding file on the computer. Go to the search and if the file is not found, refer to the database management target file management table, and if the file is registered there, use the above SQ.
The L conversion / control processing unit is activated. The SQL conversion / control processing unit refers to the contents of the conversion information file to realize access to the database with the database management system, and interrupts the OS again when returning the data requested by the program. The file management system unit works to link with the current program.

The database access control apparatus according to the second aspect of the present invention is the file I / O of the current program.
Each time a simple command corresponding to is called, it works in conjunction with the SQL conversion / control processing unit to control access to the database.

The database access control apparatus according to the third aspect of the present invention provides a network processing unit between the computers running the current program group and the computer having the database even if the computer running the current program group and the computer having the database are different. I was able to do it.

[0010]

Embodiments will be described below with reference to the drawings. An embodiment of the database access control device according to [claim 1] of the present invention will be described with reference to FIG. In FIG. 1, 1 is a current program group that requests file input / output processing, and 2 is a part of an OS that manages file input / output of the current program group. A routine for accessing a database is added as an error processing at the time of file access. The file management system unit 3 is a database management target file management table for registering a file name of a file which is a database accessed by the current program.

Reference numeral 4 is a database management system having a database that also takes in the data of the current program. Reference numeral 5 is conversion information describing conversion rules for associating an instruction issued from the current program group with an instruction to act on the database management system 4. Reference numeral 6 denotes a SQL conversion / control processing unit for converting the command from the current program group 1 into a database language and for returning the data returned from the database management system to the current program.

Next, the operation will be described. First, the operation of the file management system unit 2 in FIG. 1 will be described with reference to FIG. 2, and the operation of the SQL conversion / control processing unit 6 will be described with reference to FIG.
Will be explained. The contents of the conversion information file 5, which is a point in FIG. 3, will be described with reference to FIG. 2 shows the operation of the file management system unit 2 on the file I / O processing performed by the current program group 1.

When the current program group 1 requests a certain file access, the file management system unit is executed. If it is true to the determination in step S21 as to whether or not the file exists, file I / O processing is performed according to normal OS processing in step S22, and then step S23.
Then, the process for returning control to the current program group is executed. If there is any doubt about the determination in step S21, a process for referring to the database conversion target file management table is performed in step S24, and it is determined in step S25 whether the file is registered. Step S
If the judgment in 25 is suspicious, the error process of step S26 (the requested file does not exist) is executed similarly to the error process at the time of normal file I / O, and step S23 is executed.
Processing for returning control to the current program group of.

If the judgment in step S25 is true, a process for linking with the SQL conversion / control processing unit in step S27 is performed to obtain a result, and a process for returning control to the current program group in step S23 is performed. Ends the process. Figure 2
With the operation shown in (1), it is possible to obtain information from the database as if the current program group is performing the file I / O processing as it is currently. Next, the contents of the processing associated with the SQL conversion / control processing unit in step S27 of FIG. 2 will be described.

FIG. 3 is a diagram showing the operation of the SQL conversion / control processing unit 6 located between the command of the current program group 1 and the database management system 4 for converting / controlling information. Here, the file read from the current program (ACCESS MODE IS S
EQUENTIAL) instruction, an example is shown in which database access processing is performed. The I / O commands 21 to 23 issued by the file management system unit 2 in response to the instruction of the current program group 1 are passed to the SQL conversion / control processing unit 6 corresponding to the program, and the conversion information file (in the figure, Necessary processing is executed based on the contents of 5).

Specifically, it is stored in the conversion information file 5 that the commands of SQL-1 to -3 of 24 to 26 are executed with respect to 21 I / O commands (OPEN). A required process is requested of the database management system 4, and the processes of SQL-1 to -3 of 24 to 26 are executed there. Similarly, 22 I / O commands (READ)
In response to this, SQL (FETCH) 27 is processed on the database side, and the data on the database side is fetched into the current program side. The corresponding SQL (COMMIT WORK) 28 is also processed for the I / O command (CLOSE) of 23. In order to make the operation shown in FIG. 3 easier to understand, the contents of the conversion information file 5 are shown below.

FIG. 4 shows the contents of the conversion information file 5 corresponding to the operation shown in FIG. 3 as an example.
The conversion information file 5 includes a command correspondence description section 31 that describes the correspondence between COBOL commands and SQL commands, which is a database language, and a data structure that describes the correspondence between the record structure during file access and the database table structure. The correspondence description part 32 exists. In the instruction correspondence description section 31, file access instructions in COBOL language such as OPEN and READ are described in a form including the level of additional information such as SHARE form and I / O mode. or,
In the data structure correspondence description part 32, information such as which data in the table normalized as the database when the current file is accessed is described. The above is a combination of the operations described in FIGS. 2 to 4, and the operation according to the present invention is realized.

According to the above embodiment, it is possible to shift to the program and system for obtaining information from the database without changing the processing of the current program. As a result, it becomes possible to share data among a plurality of programs and to centrally manage the data, and it is possible to obtain the benefit of making a database. In addition, the amount of work required to build a database is much less than the conventional method of reviewing the entire processing of the current program and rebuilding the entire system because the work of changing the current program is unnecessary. Can be expected.

FIG. 5 is a block diagram of another embodiment. In this embodiment, the present program group is converted into a database with a small amount of modification to achieve the task. In FIG. 1, reference numeral 1 is a database I / O obtained by modifying the file I / O command unit into a simple command that can be recognized by the SQL conversion / control processing unit 6.
A current program group as an O command section, and 4 is a database management system having a database that also takes in the data of the current program group. Based on the contents of the conversion information file 5, the SQL conversion / control processing unit 6 converts the command issued from the current program group No. 1 into the language for the database to perform the information transfer processing, or from the database management system 4. The SQL conversion / control processing unit for returning the returned information to the current program group 1 is shown.

FIG. 6 is a block diagram of still another embodiment. In this embodiment, a computer on which the current program operates and a computer having a database are configured differently.
The database management system 4 is provided in a computer B (8 in the figure) different from the computer A (7 in the figure) on which the current program group 1 operates. The command issued by the current program group 1 is passed to the SQL conversion / control processing unit 6 via the network processing unit 9. The SQL conversion / control processing unit 6 converts the content of the conversion information file 5 into an instruction to be passed to the database management system 4. The command in the language for the database performs the requested processing in the database management system 4, and then returns the result to the SQL conversion / control processing unit 6. The returned information is returned to the current program group 1 via the network processing unit 9,
It can function as if the current program group 1 accessed the file system.

[0021]

As described above, according to the present invention, the database is used both when the server machine for the database is provided separately from the computer having the current system and when the database system is constructed on the same computer. It is possible to realize the same function as the current system by adding a database to the program of the existing system without modification or with a small modification amount. Further, it is possible to construct a new program that can directly access the database.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an embodiment of a database access control device according to the present invention.

FIG. 2 is a process flow chart of the operation of the file management system unit.

FIG. 3 is a process linkage diagram showing an example of a conversion information file action.

FIG. 4 is a diagram for explaining the conversion information file shown in FIG.

5 is a functional block diagram showing another embodiment modified from FIG.

FIG. 6 is a functional block diagram showing another embodiment obtained by modifying FIG. 5;

[Explanation of symbols]

 1 current program group 2 file management system section 3 database management target file management table 4 database management system 5 conversion information file 6 SQL conversion / control processing section 7 computer A (computer running current system) 8 computer B (database server machine) 9 Network processing unit

Claims (3)

[Claims] 1. A computer system having a program group for accessing a plurality of files and having a database management system for managing a database in which data of the plurality of files is fetched, storing a procedure for converting a file access instruction into a database access instruction. A conversion information file to be stored, an SQL conversion / control processing unit for converting an access command and controlling information using the conversion information file, and a file which is a database among the files accessed by the current program are registered. A routine for linking the database conversion target file management table and the above-mentioned SQL conversion / control processing unit using the database conversion target file management table when the corresponding file is not found on the computer when accessing the file of the current program is added. And a file management system part of the computer operating system. 2. A database I in which a file I / O command section of a current program designed / manufactured to access a file in the current program group is changed to a simple command that can be recognized by an SQL conversion / control processing section. The database access control device according to claim 1, wherein the / O command unit is provided by being modified. 3. A current program group consisting of a current program group and a database I / O command section in which the file I / O command section of the current program is changed to a simple command that can be recognized by the SQL conversion / control processing section, and conversion. A database access control device comprising a SQL conversion / control processing unit having an information file, wherein a SQL conversion / control processing unit is provided between the two for control processing.