JP3006723B2 - Database access device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database access apparatus capable of accessing a plurality of different databases from the same application.

[0002]

2. Description of the Related Art Conventionally, an application for accessing a database is a database management system (hereinafter referred to as D).
(Abbreviated as BMS) is directly used. The database access interface of the DBMS is different for each DBMS. To access a plurality of different databases,
It is necessary to create an application with a different interface for each type of DBMS.

[0003]

As described above, in the conventional database access method, there is a problem that an application must be created with a different interface for each type of DBMS, and when the type of database changes. However, there is a problem that the application must be corrected.

[0004] The present invention has been made in view of the above,
It is an object of the present invention to provide a database access device that can access a plurality of different databases from the same application.

[0005]

In order to achieve the above object, a database access device according to the present invention is a database access device capable of accessing a plurality of different databases from the same application. A database access processing processor provided for each type and driving a database management system of each database, and a database access processing processor corresponding to a database management system of a target database to be started at the time of starting access to a database, are activated. The identification information of the logical access path of the target database is generated and held in the memory, and when the access to the target database ends, the database access processing processor corresponding to the database management system of the target database Logical access path management means for deactivating the logical access path to the target database held in the memory, and identification information of the logical access path holding the database access request from the application in the memory And a database access allocating means for allocating to the database access processing processor corresponding to the database management system for the target database, wherein the database access processing processor responds to the database access request of the application allocated by the database access allocating means. The point is to convert to a unique database access interface.

[0006]

In the database access apparatus of the present invention, a database access processor for converting a database access request from an application into a database access interface unique to the database management system is provided for each database management system. The activation of the corresponding database access processor and the generation and holding of the identification information of the logical access path of the target database are performed by the database logical access path management means, and the database access request from the application is database access distribution means by the logical access path identification information. To each database access processor, and the database access processor passes through the database management system For accesses to database, and delete the logical access path identification information to the database access process deactivation and database processor database logical access path management unit when accessing the end of the database.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention. In FIG. 1, reference numeral 10 denotes an application for accessing a database. Reference numeral 11 denotes a logical access path management unit, which is a database access processor 14,
14a (A, B) are activated and deactivated, and identification information of a logical access path to the database is generated and deleted. Reference numeral 12 denotes a memory for storing identification information of a logical access path. Reference numeral 13 denotes a distribution unit that distributes a database access request from an application to one of the database access processors 14 or 14a. 15 and 15a are different types of DBs, respectively.
MSs 16 and 16a are databases (A and B) managed by DBMSs 15 and 15a, respectively.

First, the operation at the time of starting access to the database will be described. The application 10 inputs a database access start request (open) through the connection line 1. Here, the case where the database 16 (A) is specified will be described. Logical access path management means 1
1 is a management system D for the database 16 (A).
An activation request is sent to the database access processor 14 (A) corresponding to the BMS 15 (A) through the connection line 2 and the activation request is activated. Then application 1
The identification information for identifying the logical access path between 0 and the database 16 (A) is generated and recorded in the memory 12 through the connection line 3. Then, the identification number ("1") in the logical access path identification information is returned to the application 10 via the connection line 1. The details of the logical access path identification information will be described later. Thereafter, the application 10 accesses the database 16 (A) using the returned logical access path identification number.

[0010] The application 10 can subsequently open another database 16a (B). In this case, by the same operation as the opening of the database 16 (A), the identification number ("2") of the logical access path different from that for the database 16 (A) is returned to the application 10 as a result.

Next, the operation at the time of accessing the database will be described. The application 10 inputs an access request for the database 16a (B) through the connection line 4. At this time, the identification number of the logical access path is also input. The case where "2" is input as the identification number of the logical access path will be described. Database access distribution means 13
Accesses the memory 12 through the connection line 5 based on the input identification number "2" of the logical access path, and corresponds to the identification number "2" from the logical access path identification information stored therein. Get the entry address of the database access processor. Then, the input database access request is passed to the database access processor 14a (B) through the connection line 6 'corresponding to the entry address. The database access processor 14a (B) converts the database access request passed from the database access distribution means 13 to the database access interface of the DBMS 16a (B), and converts the request to the DBMS 15a through the connection line 7a.
(B), the data stored in the database 16a (B) is accessed. The result of the access is returned to the application 10 through the reverse route (15a → 7a → 14a → 6a → 13 → 4).

When the application 10 specifies a logical access path identification number "1" and inputs a database access request, the database 16 is operated in a similar manner to the operation principle.
(A) can be accessed.

Next, the operation at the end of accessing the database will be described. The application 10 inputs a database access end request (close) through the connection line 1. At this time, the identification number of the logical access path is also input. Here, the case where the identification number “1” is designated will be described. The logical access path management means 11 accesses the memory 12 through the connection line 3, and from the logical access path identification information stored therein, the entry address of the database access processor 14 (A) corresponding to the identification number "1". Get. Then, a deactivation request is sent to the database access processor 14 (A) through the connection line 2, and this is deactivated. Then, memory 1
2 deletes the logical access path identification information. The same applies to the case where the application 10 specifies and closes the identification number “2” of the logical access path.

Here, the details of the open processing in the logical access path management means 11 will be described with reference to FIG. To open the database, a logical name of the database to be accessed by the application is specified, and a start request is input to the logical access path management unit 11. First, the logical access path management unit 11 refers to the first control table shown in FIG. 2A to obtain the type of the DBMS corresponding to the database name. Next, referring to the second control table shown in FIG. 2B, the entry address of the database access processor corresponding to the DBMS type is obtained. Then, an activation request is sent to the target database access processor using this entry address. Thus, the first
By obtaining the entry address of the target database access processor in the two stages of the control table and the second control table, the application can use the alias when specifying the database. For example, database A
Can be specified as the database X. Further, the DBMS type corresponding to the database X is set to the DBMS type.
It can be changed to S (B). That is, the actual database can be changed without being aware of the application.

Thereafter, the logical access path management means 11 assigns an identification number of the logical access path, and records it on the memory as logical access path identification information together with the above-described entry address. The logical access path identification information will be described in detail with reference to FIG. The logical access path identification information includes an identification number unique within the logical access path identification information and an entry address of the corresponding database access processor. When a database access request and an access end request are input, an entry address corresponding to the specified identification number is obtained, and the request can be passed to a target database access processor. In database open processing,
The assignment of the identification number performed by the logical access path management means searches a record in which no entry address is recorded in the logical access path identification information, and assigns the identification number.
In FIG. 3, the identification number newly assigned in the open processing is “3”, and the entry address of the database access processor corresponding to the identification number “1” is “100540”.

As described above, in the present database access apparatus, access to a plurality of databases is enabled by managing the identification information of the logical access path to the database and allocating the database access request based on this information. A database access processing processor is prepared for each type, and the processor converts a database access request of an application into a database access interface for each DBMS, thereby enabling access to different types of databases.

[0017]

As described above, according to the present invention,
It is not necessary to create an application for each type of DBMS as in the conventional technology. Access to a plurality of databases can be achieved by managing the identification information of the logical access path to the database and distributing the database access request based on this information. It becomes possible to access different types of databases by preparing a database access processing processor for each type of DBMS and converting the database access request of the application into a database access interface for each DBMS by this processor.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a database access device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a control table for processing by a logical access path management unit at the start of database access in the database access device of FIG. 1;

FIG. 3 is a diagram showing the contents of logical access path identification information used in the database access device of FIG. 1;

Continuation of the front page (56) References JP-A-62-232064 (JP, A) JP-A-63-171741 (JP, A) JP-A-1-209572 (JP, A) JP-A-1-211029 (JP) JP-A-2-87274 (JP, A) JP-A-62-234431 (JP, A) JP-A-2-137039 (JP, A) JP-A-63-245753 (JP, A) Tetsuo Ikeda et al. , "A Study of the DB Gateway Function for Information Distribution", Information Processing Society of Japan 41st (Late 1990) National Convention Lecture Papers pp. 4-176 to 4-177 (September 4, 2002) (58) Field surveyed (Int. Cl. ⁷ , DB name) G06F 17/30 G06F 12/00 513

Claims (1)

(57) [Claims] 1. A database access device capable of accessing a plurality of different databases from the same application, wherein the database access processor is provided for each type of database management system of each database and drives a database management system of each database. Activate the database access processor corresponding to the target database management system of the target database at the start of access to the database, generate and hold identification information of a logical access path to the target database in a memory, and store the identification information in the target database. Deactivates the database access processor corresponding to the database management system of the target database at the end of the access of the target database, and establishes a logical access path to the target database held on the memory. Database logical access path management means for erasing separate information; and database access distribution for distributing a database access request from an application to a database access processor corresponding to a database management system of a target database based on identification information of a logical access path held in a memory. Means, wherein the database access processor converts the database access request of the application allocated by the database access allocation means to a database access interface specific to the corresponding database management system.