JPH0765032A - Information processing system with database language conversion function - Google Patents

Abstract

(57) [Summary] [Purpose] To make a database inquiry to multiple different DBMS in a unified manner without being affected by the DBMS. [Structure] When the standard format SQL is transmitted from the client computer 4 to the server computer 5, the server computer 5 positions it in the entry in the conversion rule management table 54 having the database name designated by the SQL, and the SQL pointed to by the entry information. Using the SQL conversion routine in the conversion library 52, the standard format SQL is converted into the SQL of the format unique to the DBMS 32-i that manages the database 31-i (i = 1 to 3) of the specified database name, and the same entry information To the server computer 3-i pointed to by. The DBMS 32-i executes a specific format SQL to access a specified database. The result data of this access is converted into the standard format using the data conversion routine in the data conversion library 53 indicated by the entry information, and is returned to the requesting computer 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts a standard format database language issued by an inquiry request source into a format peculiar to DBMS when making a database inquiry to a plurality of different database management systems (DBMS), The present invention relates to an information processing system having a database language conversion function of converting access result data from a unique format to a standard format and returning the converted result data to a request source.

[0002]

2. Description of the Related Art In a plurality of DBMS (database management system) environments (hereinafter referred to as "multi-DB environment"), the database language SQL (Structured Query Language) supported by each DBMS is the D
It is generally in a format specific to BMS.

Therefore, in a conventional information processing system of a multi-DB environment, when a database inquiry is made to each DBMS, the application program operating on the inquiry requesting computer is unique to each DBMS. It was configured to be able to issue SQL. Further, the application program on the request source computer is also configured to be able to convert the access result data into a format that can be processed after being received by the request source computer from the DBMS because the access result data has a unique format.

Normally, this multi-DB environment is constructed network-wide, and a computer equipped with a DBMS is used as a server computer and a personal computer (P
C) and the workstation (WS) are client computers that are the source of the inquiry request to the server computer. To create an application program on this client computer, the programmer must access all DBMSs, as will be apparent from the above description.
It was necessary to understand the SQL language format and the data representation format unique to the.

[0005]

As described above, in the conventional multi-DB environment information processing system, the programmer configures the multi-DB environment when creating an application program that operates on the client computer of the system. There is a problem that it cannot be created unless all the SQL syntax and data format of DBMS are understood. This is a problem common to all types of application programs and impairs software productivity and distribution. Another DB
Even when the MS participates in this multi-DB environment, there is also a problem that all the application programs created so far must be changed to support the new DBMS.

The present invention has been made in consideration of the above circumstances, and an object thereof is to make a database inquiry from a client computer to a plurality of different DBMSs according to an application program in a multi-DB environment.
An object of the present invention is to provide an information processing system that can be performed in a unified manner without being affected by the MS and thus can improve productivity of application programs.

[0007]

According to the present invention, there are provided a plurality of first databases equipped with a DBMS (database management system) that supports a specific format SQL (database language) and manages a database composed of specific format data. A server computer, a first network to which the plurality of first server computers are connected, at least one client computer that makes a database inquiry by standard SQL, and at least one client computer are connected It is characterized by comprising a second network and a second server computer connected to the first and second networks.

The second server computer converts the standard format SQL into a predetermined specific format SQL.
The first conversion routine registering means in which the conversion routine of No. 1 is registered corresponding to each DBMS and the second conversion routine for converting the result data of the database inquiry from the DBMS into the standard format correspond to each DBMS. Second conversion routine registration means registered respectively, a database managed by each DBMS, and the same DBMS
A conversion routine corresponding to the above, a second conversion routine corresponding to the same DBMS, and a plurality of entries in which information designating the network address of the first server computer equipped with the same DBMS is registered. A DBMS having a rule management table and managing a database having a database name designated by the SQL when the standard format SQL sent from the client computer is received.
Using the first conversion routine corresponding to
To the first server computer equipped with the DBMS, and the result data in the unique format returned from the destination first server computer is sent to the DBMS as the execution result of this unique format SQL. Is converted into standard format data by using the second conversion routine corresponding to and returned to the client computer as the database inquiry source.

[0009]

In the above configuration, the client computer is
According to the application program, SQL of the standard format applied by the program is issued and sent to the second server computer.

Upon receiving the standard format SQL from the client computer, the second server computer positions it in the entry in the conversion rule management table having the database name specified by the SQL and registers the first registered SQL in the entry. First, the first conversion routine name is extracted and the first conversion routine (SQL conversion routine) indicated by the routine name is extracted.
Call from the conversion routine registration means of. The second server computer executes the called SQL conversion routine to convert the received standard format SQL syntax to the same SQL statement.
A network registered in the entry in the conversion rule management table which is converted to the unique format supported by the DBMS corresponding to the database having the database name specified by L and the converted unique format SQL. The address is used to send to the corresponding first server computer.

When the specific format SQL is sent from the second server computer to the first server computer, the DBMS in the first server computer executes the same SQL and has the table name designated by the SQL. Perform database access such as searching a table. Then, the DBMS returns the result data of this database access to the second server computer.

When the second server computer receives the result data returned from the DBMS in the first server computer,
The second conversion routine name registered in the entry in the conversion rule management table that has been positioned earlier is taken out, and the second conversion routine (data conversion routine) pointed to by the routine name is converted into the second conversion routine registration means. Call from. The second server computer executes the called data conversion routine to receive the result data (the result data obtained by executing the unique format SQL).
Is converted into a standard format suitable for the application on the client computer that issued the database inquiry request, and is returned to the client computer.

As described above, the client computer can perform unified access to a plurality of different DBMSs only by issuing SQL in the standard format in accordance with the application program on its own computer.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of an information processing system having an SQL conversion function according to an embodiment of the present invention.

In the figure, 1 and 2 are networks. For example, three heterogeneous database access server computers 3-1 to 3-3 are connected to the network 1, and a client computer 4 is connected to the network 2.

Each of the server computers 3-1 to 3-3 has a unique format S.
Database access is performed according to a database inquiry using QL. Server computer 3-1 to 3-3
Is a database 31-1 to 3 consisting of unique format data
Supports 1-3 and native SQL, and database 3
DBMS (database management system) 32-1 to 32-3 for managing 1-1 to 31-3 (DBMS # 1 to DBMS #
3) and.

The databases 31-1 to 31-3 are table 3
10-1 to 310-3 are included. Database 31-1 ~
31-3 (to identify) the database name is "DB #
1 "to" DB # 3 ", and tables 310-1 to 310
-3 (to identify) the table name is "TABLE #
1 "to" TABLE # 3 ".

The client computer 4 is a standard format SQ.
A database inquiry using L is performed.
Therefore, the client computer 4 has a standard format SQ.
An application program 41 for accessing the database by L is installed. The application program 41 is not limited to one type.

A multi-database control server computer 5 is connected between the networks 1 and 2. This server computer 5 converts the standard format SQL issued by the client computer 4 into a format unique to the DBMS 32-i that manages the database 31-i to be accessed and sends it to the corresponding database access server computer 3-i. At the same time, it controls the conversion of the access result data of the computer 3-i according to the converted SQL of the specific format into the standard format and the return to the client computer 4. This control is performed according to the multi-database server program 51.

The server computer 5 has an SQL conversion library 52, a data conversion library 53, and a conversion rule management table 54. SQL conversion library 52
As shown in FIG. 2, the SQL conversion routine 520-1
~ 520-3 are registered. SQL conversion routine 52
0-1 to 520-3 is a standard format SQL DBMS 32-1.
32-3 is a program for converting to SQL of a proper format supported by. SQL conversion routine 520-1 to
The routine name of 520-3 is "SQL conversion routine # 1"-
This is "SQL conversion routine # 3".

In the data conversion library 53, data conversion routines 530-1 to 530-3 are registered as shown in FIG. Data conversion routines 530-1 to 530-3
Is a program for converting the database access result data of the unique format from the DBMS 32-1 to 32-3 into the standard format. Data conversion routines 530-1 to 53
The routine names 0-3 are "data conversion routine # 1" to "data conversion routine # 3".

As shown in FIG. 4, the conversion rule management table 54 is composed of conversion rule management entries 540-1 to 540-3 corresponding to the DBMS 32-1 to 32-3. Each conversion rule management entry 540-1 to 540-3 is a DBMS 32.
-1 to 32-3 manage database 31-1 to 31-3 database name parameter 541 showing the database name
(Registration field), an SQL conversion rule name parameter 542 (registration field) indicating the routine name of the SQL conversion routine corresponding to the DBMS 32-1 to 32-3, and the DB
Data conversion rule name parameter 543 (registration field) indicating the routine name of the data conversion routine corresponding to MS 32-1 to 32-3, and server computers 3-1 to 3-equipped with DBMS 32-1 to 32-3 3 and a network address parameter 544 (registration field) indicating the network address (server address).

Next, the operation of the embodiment of the present invention will be described. The client computer 4 issues SQL in a standard format for database inquiry according to the application program 41, and performs database access using the SQL.

Now, in the client computer 4, the database whose database name is "DB # 1" (that is, the DBM installed in the database access server computer 3-1)
For database access (search) for the table having the table name "TABLE # 1" (that is, the table 310-1 in the database 31-1) in the database 31-1) managed by S32-1 It is assumed that a standard format SQL 61 as shown in FIG. 5A has been issued.

This SQL 61 is the client computer 4
Is transmitted to the multi-database control server computer 5 via the network 2. The multi-database control server computer 5 receives the SQL 61 transmitted from the client computer 4. Then server computer 5
Performs the following control according to the multi-database server program 51.

First, the server computer 5 receives the SQL6
1 is scanned to extract the database name “DB # 1”. Next, the server computer 5 searches the conversion rule management table 54 by the extracted database name "DB # 1", and the database name parameter 541 is "DB # 1".
And the conversion rule management entry 540-1.

The server computer 5 executes the SQL conversion routine 520-1 identified by the routine name "SQL conversion routine # 1" indicated by the SQL conversion rule name parameter 542 registered in advance in the conversion rule management entry 540-1. ,
SQ according to the multi-database server program 51
Called dynamically from the L conversion library 52.

The server computer 5 passes the received SQL 61 from the client computer 4 as an argument to the called SQL conversion routine 520-1, and the routine 52 concerned.
Perform 0-1. Then, the SQL 61 from the client computer 4 is converted into an internal character code system # 1 (for example, ASCII code system, EBCDIC code system, etc.) compatible with the syntax handled by the DBMS 32-1 (specific to the server computer 3-1), and It is set to SQL71 shown to 6 (a). The SQL 71 is returned to the calling multi-database server program 51, and control is returned to the server program 51.

Then, the server computer 5 re-executes the server program 51, searches for the database address server computer having the network address indicated by the network address parameter 544 in the translation rule management entry 540-1 which was previously located. That is, the SQL 71 returned from the SQL conversion routine 520-1 to the server program 51 is transmitted to the database access server computer 3-1 via the network 1.

This database access server computer 3
SQL71 addressed to -1 is a DB in the server computer 3-1.
It is received by MS 32-1. Upon receiving the SQL 71 from the multi-database control server computer 5, the DBMS 32-1 performs the database access process according to the SQL 71, that is, the table name in the database 31-1 is “T”.
A search process is performed for the table 310-1 of "ABLE # 1".

Then, the DBMS 32-1 converts the data (result data) resulting from the execution of SQL71 into the SQL71.
Multi-database control server computer 5 that is the sender of the
Reply to.

Then, the multi-database control server computer 5 (this database access server computer 3-1
The format of the result data from DBMS 32-1 (in
In order to convert the format unique to S32-1 to the standard format and send it back to the client computer 4, the routine name "data" indicated by the data conversion rule name parameter 543 in the conversion rule management entry 540-1 previously positioned The data conversion routine 530-1 identified by the conversion routine # 1 "
It is dynamically called from the data conversion library 53 according to the multi-database server program 51.

The server computer 5 executes the called data conversion program 530-1 and transfers the result data from the DBMS 32-1 (in the database access server computer 3-1) to the character code system compatible with the client computer 4. Convert to data representation format.

The result data after this conversion is returned to the calling multi-database server program 51, and control is returned to the server program 51. Then, the server computer 5 executes the server program 51 again to execute SQ.
The converted result data is returned via the network 2 to the client computer 4 that is the issuer of L61 (database inquiry source by SQL61).

Above, in the client computer 4,
A need arises for database access for a table with a table name "TABLE # 1" in a database with a database name "DB # 1", and the standard format SQL61 shown in FIG. Is the operation when is issued.

In this operation, the database name is "DB #
A need arises for database access for the tables with table names “TABLE # 2” and “TABLE # 3” in the databases 2 ”and“ DB # 3 ”, and according to the application program 41, FIG. ，
The same is done when SQL 62 and SQL 63 in the standard format shown in (c) are issued.

That is, the client computer 4 uses SQL6
2, when SQL63 is issued, first, the multi-database control server computer 5 uses SQL62 and SQL6.
Based on 3 and the conversion rule management table 54, the database access server computers 3-2 and 3-3 (the network address) of which the DBMS 32-2 and 32-3 are mounted, which are the database inquiries, are recognized. Next, the multi-database control server computer 5 stands between the recognized database access server computers 3-2 and 3-3 and the client computer 4 which is the inquiry source, and executes the (SQL conversion routine 520-2 in the SQL conversion library 52). , 520-3) standard format SQL62, SQL63 to the inquiry destination DBMS 32-2, 32-3 specific format of FIG.
Conversion to SQL72, SQL73 shown in (b) and (c), and the corresponding SQL72, S from DBMS 32-2, 32-3
QL73 execution result data (Data conversion library 5
According to the data conversion routines 530-2 and 530-3 in 3)
Perform conversion and.

As a result, the client computer 4 sends a database inquiry to the network address of the database access server computer 3-i in which the DBMS 32-i (i = 1 to 3) managing the database exists, and the DBMS 32-i. It can be performed uniformly without knowing the SQL syntax and data format unique to i. Therefore, the application program 41 can be easily created.

Next, a brief description will be given of a case of newly adding a DBMS or a case of deleting an existing DBMS. First, when a new DBMS is added, the SQL conversion routine corresponding to the new DBMS is registered in the SQL conversion library 52 and the data conversion routine is also registered in the data conversion library 53, and the DBMS is registered in the conversion rule management table 54. It is sufficient to secure the entry corresponding to. In this case, it is not necessary to change the application program 41 on the client computer 4 in order to support the new DBMS.

Next, when deleting the DBMS, the D
The SQL conversion routine corresponding to the BMS may be deleted from the SQL conversion library 52, the data conversion routine may be deleted from the data conversion library 53, and the entry in the conversion rule management table 54 corresponding to the DBMS may be deleted. Here, it is not always necessary to delete the SQL conversion routine and the data conversion routine. In the above embodiment, the case where the number of client computers 4 is one has been described, but the case of having a plurality of client computers 4 is also applicable.

[0041]

As described above in detail, according to the present invention,
In the multi-DB environment (multi-database system environment), the syntax of the database language for the database query of the standard format issued from the client computer in accordance with the application program on the computer is targeted for database access by the second server computer. After conversion to a format unique to the database management system (DBMS) using the first conversion routine specified by the entry in the conversion rule management table corresponding to the database, this native format database language is specified for the entry. According to the network address of the first server computer, the unique format returned to the second server computer from the destination first server computer as the execution result of this unique format database language. The result of Since the data is converted into standard format data by the second computer using the second conversion routine specified by the entry and returned to the client computer that is the source of the standard format database language, Even if the client computer does not know the type of DBMS and the network address of the first server computer on which the DBMS is installed, it simply issues a standard format database language according to the application program on its own computer.
Database access of a plurality of different DBMS can be performed in a unified manner. Therefore, the programmer can create various application programs that operate on the client computer without necessarily understanding the syntax and data format of the database language of the DBMS that constitutes the multi-DB environment. Productivity is improved.

Further, according to the present invention, a new DBMS
When adding or deleting the DBMS, the corresponding first conversion routine (SQL conversion routine) and second conversion routine (data conversion routine) are newly registered or deleted on the second server computer. However, it can be dealt with only by adding or deleting an entry in the conversion rule management table, and it is not necessary to modify the application program on the client computer.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an information processing system having an SQL conversion function according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of an SQL conversion library 52 in FIG.

3 is a diagram showing a configuration example of a data conversion library 53 in FIG.

4 is a diagram showing a configuration example of a conversion rule management table 54 in FIG.

FIG. 5 is a diagram showing an example of standard format SQL applied in the embodiment.

6 is an S of a unique format corresponding to the standard SQL of FIG.
The figure which shows an example of QL.

[Explanation of symbols]

1, 2 ... Network, 3-1 to 3-3 ... Database access server computer, 4 ... Client computer, 5 ... Multi-database control server computer, 31-1 to 31-3 ... Database, 32-1 to 32-3 ... DBMS (database management system), 41 ... Application program,
51 ... Multi-database server program, 52 ... S
QL conversion library, 53 ... Data conversion library, 5
4 ... Conversion rule management table, 310-1 to 310-3 ... Table, 540-1 to 540-3 ... Conversion rule management entry, 5
41 ... Database name parameter, 542 ... SQL conversion rule name parameter, 543 ... Data conversion rule name parameter, 544 ... Network address parameter.

Claims (1)

[Claims] 1. A plurality of first server computers equipped with a database management system that supports a database language of a specific format and manages a database of data of a specific format, and the plurality of first server computers are connected to each other. A first network, a at least one client computer that makes a database inquiry in a standard format database language, a second network to which the at least one client computer is connected, and a standard format database language in advance. A first conversion routine registration means for registering a first conversion routine for converting into a database language of a defined unique format, corresponding to each of the database management systems, and a database inquiry from the database management system. Result data Second conversion routine registration means for registering a second conversion routine for converting to a standard format respectively corresponding to the management system, a database managed by the database management system of the first server computer, The first conversion routine corresponding to the management system, the second conversion routine corresponding to the management system, and information designating the network address of the first server computer equipped with the management system are registered. A second server computer connected to the first and second networks, having a conversion rule management table including a plurality of entries, and receiving the standard format database language transmitted from the client computer. Then, the conversion rule pipe with the database name specified by this receiving database language The entry in the table is searched, the first conversion routine indicated by the entry information is called from the first conversion routine registration means, and the database of the database name specified by the reception database language is created based on this conversion routine. After converting into a database language of a format unique to the database management system to be managed, this database language of the native format is transmitted to the first server computer having the network address indicated by the entry information, and the native format database language is transmitted. As a result of executing
The result data in the unique format returned from the first server computer of the transmission destination is converted into standard format data based on the second conversion routine in the second conversion routine registration means indicated by the entry information. And a second server computer that returns the received database language to the client computer that is the sender of the received database language.