JPH04139546A - Relational data base device - Google Patents

Abstract

PURPOSE:To simply add and delete the data by providing a pointer which shows an attribute value or plural attribute value records as the value of an attribute value field of a relational table. CONSTITUTION:A pointer P is provided to show an attribute value or plural attribute value records as the value of an attribute value field of a relational table alpha. Thus a relational data base device is obtained and applies an attribute value and the pointer with switching according to a fact whether 2 corresponding attribute values are available or not. In other words, the pointer P can point the attribute value records beta and gamma in the attribute value field of the table alpha. As a result, the non-regulated data is easily processed and at the same time the number of necessary storage areas is decreased.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method for constructing a relational database.

BACKGROUND OF THE INVENTION In recent years, databases have been widely used, and their configuration is one of the important issues.

Conventionally, relational code information storage devices cannot handle a non-normal data structure in which one attribute value has a plurality of other attribute values as shown in FIG. 4(a) as a relational table. First, it was necessary to convert it into a normal form as shown in FIG. 4 in advance.

Problems to be Solved by the Invention Conventional database creators have had to take the trouble of converting non-normal form data into normal form data prior to creating relational tables.

In addition, normal form data tends to have a larger amount of data than non-normal form data, so when performing data processing such as updating or inserting, there are many items that need to be set, which tends to make the process complicated. In addition, there is a problem in that the storage area used becomes large.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a relational database device that can easily perform data processing operations on non-normal data and can also reduce the amount of storage space used.

Means for Solving the Problems In order to achieve the above object, the present invention provides a pointer to one attribute value or a plurality of attribute value records, and the corresponding attribute value is set as the value of the attribute value field of the relationship table. This is a relational data bene device that switches and provides one attribute value and a pointer depending on whether there are two or more.

Effect: With the above configuration, the present invention allows a pointer to point to a plurality of attribute value records in the attribute value field of the relationship table C.

This will be explained with reference to the drawings.

FIG. 1 is a schematic diagram showing the configuration of a relational database in a database device according to an embodiment of the present invention. In the figure, α is a relationship table, β, r are multiple attribute value records, '11
'C21' bll 'b12' ”21 'C
111'21 I C22+ '23 is the attribute value, p
p*Pr is a pointer to a multiple attribute value record. FIG. 2 is a flowchart showing the process of inserting a 1-tuple into a relational table, and FIG. 3 is a flowchart showing the process of deleting a 1-tuple. In FIG. 2 and FIG. 3, steps 1 to 15 will explain the operation in the above configuration showing details of processing. First, the process of inserting a tuple into a relational table will be explained.

FIG. 1 (-) is a normalized relational table with no duplication of attribute values, and has the same structure as a normal relational database. In this relational table α, the attribute value is “”111b12. C1
1]. Consider the case where a tuple is inserted. Second
In step 1 of the diagram, it is determined that the matching attribute values are "11" and "11", and in step 2, it is determined that the matching attribute values are "11" and "11".
11 t cll -' is extracted, and in Nuteb 3, the matching attribute value a11 + '11
The value of the attribute value field other than bll is extracted. Next, in step 4, it is determined that bll is not a pointer to a multiple attribute value record, and in step 6, bll
A multiple attribute value record β consisting of l and b12 is created, and a pointer pβ to the record is written where bll was. Next, in step 7, it is determined that the metallicity value has ended, and the process ends. At this stage, the structure of the relationship table is shown in Figure 1 (
b) Next, in this relation table [C21' b2
1 and '22-', the structure shown in FIG. 1(C) is obtained through the same operation as above and the processing steps 1.2, 3, 4.6, and 7 in FIG. 2. If the tuple [C21"21"23] is further inserted into this relational table, step 4 will be performed after the processing steps 1, 2, and 3.
It is determined that p is a pointer to a multi-attribute value record, and in step 6, C23 is added to the multi-attribute value record γ, followed by step 7, resulting in the structure shown in FIG. 1 ((1)).

Next, from the relational table with the structure shown in Figure 4 (, i), [C211
The case of deleting the tuple "21, '23)" will be explained.

In step 9 of FIG. 3, the tuple to be deleted is found, and in step 1o it is determined that the corresponding tuple has been found by following the pointer p, and the process proceeds to step 11. In step 11, 023 is deleted from the multiple attribute value record γ pointed to by pointer p, and in step 12, there are still two remaining attribute values of γ, so the process moves to step 14, and this ends the metallic value, so the process ends. . At this stage, the structure of the relational table becomes as shown in FIG. 1(C). Furthermore, when deleting the tuple [C21'"21 t C22] from the relation table in (C), the process is performed in steps 9, 1o and 1 in FIG.
1, and in step 12 it is determined that there is only one attribute value '21' in the attribute value record in the multiple attribute value record, and in step 13 C21 is added to the field where p was.
, delete γ, go through step 14, and get 0 in Figure 1.
)) structure. 0)) to C”111b12101
When deleting the tuple 1'', the same processing procedure is followed, resulting in the structure shown in FIG. 1 (-).

As described above, according to the relational database device of the embodiment of the present invention, a pointer indicating one attribute value or a plurality of attribute value records is given as the value of the attribute value field of the relational table, and the way of giving is the pointer that indicates the corresponding attribute value. By providing the pointer when there are two or more, it is possible to cope without increasing the storage area of the field, and data addition and deletion processing can be easily performed by machine processing.

Effects of the Invention As is clear from the above embodiments, the present invention provides a pointer indicating a record of one attribute value or a plurality of attribute values as an attribute value in an attribute value field of a relationship table. When there is one attribute value, which attribute value is given, and when there are multiple attribute values, a pointer indicating the record containing the attribute value group is given, so that the field can be memorized even when there are multiple attribute values. It can be handled without increasing the width of the area, and data can be easily added and deleted using machine processing.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a data arrangement in a relational database device according to an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of data addition processing in a relational database device according to an embodiment of the present invention, and FIG. FIG. 4 is a flowchart showing the operation of data deletion processing in a relational database device according to an embodiment of the present invention, and FIG. 4 is a second diagram showing the arrangement of data for a plurality of attribute values in a conventional relational database device. α...Relationship table, A, B and C...Attribute, a. b and C...one attribute value, p...pointer, β and γ...multiple attribute value record. Name of agent: Patent attorney Akira Okaji and two others c-, -J plug αbx - attribute value P-ko;

Claims (1)

[Claims] One attribute value, as the value of the attribute value field of the relationship table,
Alternatively, a relational database device provides a pointer to a plurality of attribute value records, and switches and provides the one attribute value or the pointer depending on whether there are two or more corresponding attribute values.