JPS62295135A - How to search the database - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to the operation of a relational database using a logical language, and is particularly applicable to operations where the user is not familiar with the structure of the database. There are also database interface methods available.

[Conventional technology]

The known example closest to the invention: Database operations for relational databases (hereinafter abbreviated as RD1) are described in the literature C.G. Date, An Introduction to Database Systems (C, 1, Date: AnTnt).
, product to DatabaSe
SyStemS, Vo D,,1.

3rd edition, ADr) ISON ns[
, IEY, 1982, pp.

145-158), database operation commands written in a database operation language are embedded in a user application programmer written in a host programming language, or database operation commands are dynamically generated. This was the conventional method.

[Problem that the invention seeks to solve]

According to this method, a database manipulation language (e.g. S
Due to the nature of the QL language [1]), as long as the user knows the name of the table to be searched, the conditions, or the name of the column to be output, there is no need to use any unnecessary columns! This has the advantage that database operation commands can be created without knowing the name of -, the number of columns in a table, the arrangement of columns, etc.

However, it is necessary to master a database operation language that is different from normal host programming languages (procedural languages), and passing variables between languages requires passing, securing areas, and error codes returned from the database. No consideration was given to the fact that the burden placed on users to create and unpack application programs, such as support for

An object of the present invention is to provide a database search interface that can be easily used by users who are unfamiliar with database structures within the framework of a logical language that has a high degree of affinity with RDB operations. The purpose is to reduce the burden on users who create and debug \.

[Means for solving problems]

In a logical language, for example, the sentence ``Tsukuratis is a human being'' is expressed by the predicate ``human being'' (Tsukuratis). Here, ``human'' is a predicate name.

"Tsukuratis" is a term (hereinafter referred to as an argument).

In a logical language, by considering an RDB table as a set of predicates with the table name as the predicate name and the number of arguments as the number 11, searching, adding, and deleting rows of the table can be done using factual statements. Since it can be handled in the same way as searching, adding, and deleting databases, database operations can be naturally incorporated into the framework of the language.

However, in a predicate call in a logical language processing system, the predicate to be called is determined by the caller's predicate name and the number of arguments, and the arguments are matched and unified according to that order. When using the predicate via the table, there is a problem in that it is necessary to know the number of arguments and the correspondence between the column 11 and the arrangement of the arguments in the predicate associated with the table.

[Effect]

The present invention imizes the predicate name of a predicate associated with a table, the number of arguments, and the correspondence between columns and arguments as schema data, and uses the schema data to solve the user's incomplete problem using a logical type language. By converting a search request into a complete search request, the above problem is solved and an interface that allows database operations to be easily described using a logical language is realized.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 is a configuration diagram of a computer system to which the database search method of the present invention is applied. 1st rI2! 10 of l
1 is Rr)B, 102 is a logical language processing system that has a function of converting the search, addition, and deletion of predicates corresponding to a database table into search, addition, and deletion of table rows using a table manipulation language. be. ]0;3 is a logic language program, and is a user application program. , 1.04 and schema data 105
and a search request conversion structure 106.

FIG. 2 201 is a diagram showing a "person" table as an example of a table in the RD B of FIG. 1. Each row 2
02 represents information such as that the father of a person named al is bl and the mother is cl.

FIG. 3 shows a search request (table search predicate call) 301 accepted by the logical language processing system 102, and a search request 302 according to the present invention. Predicate 3 that accumulates schema data
3 is a diagram showing a predicate 304 that converts the search requests 03 and 302 into the search request 301 using schema data. The number and order of arguments in the 301 prosecutor's request is just like the table! , is called a complete search request because it completely matches the number and order. Furthermore, the search request 302 will be referred to as an incomplete search request.

The schema data 303 stores a table name 331, an executable predicate 332 for searching the table, and information (column/argument correspondence information) 333 indicating the correspondence between the column name of the table and the argument of the table search predicate 332. do.

Next, the operation of the search request conversion mechanism 106 will be explained. An example of a search request is: Who is the father of a person named ral? ”
Consider the following inquiry. A complete search request 301 expresses this search request. In order for the user to create the expression 301, the table ``Person'' must be created using two colors 11
, and must know that the first column represents the first name and the second column represents the father. According to the present invention, the same search request may be expressed as shown in 302. In order to create the expression 302, the user does not need to know the above information, but only needs to know that the columns ``First Name'' and ``Father'' exist in the ``Person'' table.

FIG. 4 is a flowchart for explaining the operation of the conversion i structure 106. Upon issuance of the search request 302, the search request conversion mechanism 106 is activated (step 401).
Search request transformation predicate 304 is called. When the search request conversion predicate 304 is called, it converts the passed argument into
The name 341 of the table to be searched and the search condition or column to be output are specified or broken down into a list 342 (step 402). The list of color 11 is shown in Figure 5 342
As in, the name of Kara 11 5011 equal sign 502 and value (
Variable name or constant value) Consists of 5o3. Next, 341
The schema data 303 is searched using the name of the table as a key, and the table search predicate 332 and the color 11/argument correspondence information 333 are obtained (step 403). The column/argument correspondence information is as shown in Figure 5 333, the name 511 of Kara 11,
It consists of an equal sign 512 and a value (variable name or constant value) 513. Next, variables corresponding to common columns are unified using the column list 342 and the color 11/argument correspondence information 333 (step 404).

This unification means that one element 500 is taken out from the column list 342 in FIG. 5, and the name 501 of column 11 is
This is a process of selecting an element 510 that is equal to the column name 511 of the column/argument correspondence information of No. 33 and assigning its value 513 to the value 503 (for example, setting P=X, al+Y). Then, by executing the table search predicate 332,
The requested column value is set in the variable of the column list 342 (step 405).

According to this embodiment, without modifying the logical language processing system,
It is possible to provide an interface that allows users who are not familiar with database structures to easily describe database operations using a logical language.

〔Effect of the invention〕

According to the present invention, within the framework of a logical language that makes it easy to incorporate database operations into Progera 11, it is possible to use a database even when the user has only incomplete information about the structure of the database tables. You can configure an interface that allows By providing such an interface, users can use the database by knowing only the names of the tables they are interested in, and can also write user application programs in a single language. This has the effect of reducing the user's burden when creating and debugging programs.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a computer system 11 to which the present invention is applied, FIG. 2 is a conceptual diagram of tables in a relational database according to the present invention, and FIG. 3 is a diagram for realizing a database search method according to the present invention. FIG. 4 is a flowchart for explaining the operation of the system to which the present invention is applied; FIG. 5 is an explanatory diagram for explaining the method of using schema data of the present invention. It is a diagram. 10]...Relational database, 102.
... Logical language processing system, 105... Schema data,
106... Search request conversion mechanism, 303... Schema data, 3; 3]... Table name, 332...
Table search predicate, 333... Kara l, - Argument correspondence information, 500... Storage area for list of Kara 11, 5
10... Storage area for column/argument correspondence information.

Claims (1)

[Claims] 1. A computer system comprising a database and a logical language processing system having a search function for the database,
A step of accumulating data (schema data) regarding the names of tables in the database and the number, names, and order of columns of the tables, and using the schema data to respond to incomplete search requests by the user's logical language. A method for searching a database, comprising the step of converting into a complete search request in a database operation language. 2. It is characterized by comprising the step of converting the above schema data and the user's incomplete database search request in the logical language into a complete database search request to the logical language processing system written in the logical language. The method of searching a database according to the above item 1.