JPH08278975A - Retrieval device for data base system - Google Patents

Abstract

PURPOSE: To flexibly combine plural conditions when the conditions are set and to prevent a conditional expression from being misset by performing processing in the decreasing order of process priority levels and specifying the order of retrieval differently between AND retrieval and OR retrieval. CONSTITUTION: An operator decision means 1 decides whether or not an operator of a retrieval condition is defined and a process priority means 2 checks whether or not a priority level is sets when there is a connection operator. When the priority level is set, the processing is performed according to the priority level. A kind decision means 3 decides whether the operator is OR or AND. In case of AND, the left-side condition of an operational expression is retrieved from a data base 6 and then the right-side conditional expression is retrieved according to the retrieval result. In case of OR, the left side is similarly retrieved and then the right-side conditional expression is retrieved from all the elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a search device in a database system, and more particularly to a search device capable of flexibly combining a plurality of conditions when a plurality of conditions are set in a search function.

[0002]

2. Description of the Related Art When performing a search in a general database system, an operator specifies conditions for each attribute item that is a management item, and data satisfying those conditions is extracted from the database. . Here, the attribute items include, for example, in the case of a document database system, document classifications, titles, creators, registration dates, comments indicating an outline of billing contents, and the like.

FIG. 4 shows a flow of search processing when a plurality of conditions are set based on attribute items. This figure shows an example of the search condition expression of A AND B OR C, where A, B, and C indicate each condition. When the system is given a search condition expression, the condition expression is AND (logical product),
OR (logical sum) It is sequentially checked which connection operator is used for connection.

In the logical plan, AND is given priority over OR. The system is no exception, and A in step S1
Given the AND B OR C conditional expression, S2
Then, A AND B connected by the AND operator is executed first. Next, in S3, the search target is C
Those which meet the condition of are selected, and the OR of the previous search 1 and search 2 is taken in S4 and displayed as a search result to the user in some form (S5).

[0005]

The biggest problem of the retrieval method shown in FIG. 4 is that the AND process is preferentially performed.

For example, assume that the user sets the following conditional expression.

Conditional Expression: A AND B OR C The system preferentially processes A AND B as described above. However, if the user intended the conditional expression: A AND (B OR C), the result would be completely different.

At present, in order to realize this conditional expression, it is necessary to divide the conditional expression into two expressions: A AND B OR A AND C. Although there is no problem in such a simple example, it is not easy to divide the expression in this way as the conditional expression becomes more complicated. Further, at this time, a conditional expression setting error may occur, which may eventually lead to useless search results.

[0009]

According to the present invention, in a case of searching data from a database, it is judged whether or not a connection operator of a search condition is defined, and when it is not defined, a single condition search is executed. The operator determination means determines whether or not the processing priority level is set when the operator is present, and the priority processing means which processes the higher priority level when the operator is present, and the type determination of the logical product sum of the operators. A type discriminating means to be executed, a logical sum retrieving means for retrieving the left side condition of the arithmetic expression from the database when it is judged to be a logical sum by the discriminating means, and a right side condition of the arithmetic expression for retrieving the left side condition from the database; The logical product search means searches the database for the left-side condition of the arithmetic expression when it is judged as the logical product, and when the left-side search has been completed, the right-side condition is searched from the previous search result Calculation conditions, it is determined whether or not it is completed,
When the processing is not completed, the processing priority means executes the processing again, and when the processing is completed, the execution determination means for displaying the search result is provided.

[0010]

In the operator judging means, it is first checked whether or not the connection operator is defined in the conditional expression, and if it is not defined, it is regarded as a search by a single conditional expression and executed.

Next, it is checked whether or not the processing priority level is set. If it is not defined, the conventional AND operation priority processing is performed, and if it is defined, it is processed in the order of higher priority level, and it is checked what operator is defined. In the case of AND, the conditional expression on the left side is executed, and then the one corresponding to the conditional expression on the right side is searched from the search result. In the case of OR, the left side is searched in the same manner, and then the whole elements are searched for those that correspond to the conditional expression on the right side.

The results are presented to the user at the end of all searches.

[0013]

FIG. 1 shows an embodiment of the functional block diagram of the present invention. In the figure, 1 is an operator discriminating means, which discriminates whether or not an operator of the search condition is defined. Two
Is a processing priority means, and when there is a connection operator, it is checked whether or not the priority level is set, and if it is set, the processing is performed in the order of higher priority level. 3 is a type discriminating means for discriminating whether the operator is OR or AND, 4 is a logical sum retrieving means for retrieving the OR condition when the operator is OR, and 5 is a logical product retrieving means for the retrieval under the AND condition. do. Reference numeral 6 is a database, 7 is execution determining means for checking whether all conditional expressions have been searched, and 8 is a display unit.

The operation will be described below with reference to FIGS. FIG. 2 shows a flow for creating a conditional expression, which has the concept of processing priority. When setting a conditional expression, if the number of conditions is three (two connection operators) or more, the processing priority order is set in step S16. In other cases, there is no need to set the priority order, so no setting is made.

FIG. 3 shows a search execution flow. The search first checks whether or not the connection operator is defined in the conditional expression (S20). If not defined, it is regarded as a search by a single conditional expression in S21, and the single conditional search processing is executed. If there is a connection operator, it is checked in S22 whether there is a processing priority level setting. This is defined (at S16 in FIG. 2) when setting the conditional expression, but if not defined, at S23, an AND operation process is performed as in the conventional search process. When priority processing is defined in S22,
In step S24, the processes are processed in descending order of priority level.

Next, in S25, it is checked whether the operator is the definition of AND or OR. This is A
This is because the conditional expressions on the left and right sides of the ND operator must be true, and the OR operator only needs to be true for either of them. If it is determined to be the AND operator, the left side condition of the arithmetic expression is searched from the database in S26 and S27. When it is determined that the left side search has been completed (S26), the right side condition of the conditional expression is searched and executed from the previous search result in S28.

On the other hand, when the operator is OR, the left side condition of the arithmetic expression is searched from the database, and when the left side has been searched, the right side condition of the arithmetic expression is searched from the database (S29).
~ S31). In S32, it is determined whether or not all the conditional expressions have been executed. If not completed, the processing is executed again from S24. If they have been executed, the search result is displayed on the display unit in S33.

[0018]

As described above, according to the present invention, the following effects occur.

(1) In the present invention, the setting conditions that must be set separately in the search condition setting by the conventional method can be set by one set and can be set by the conditional formula as the user imagines. Therefore, a condition setting error can be prevented and the search work efficiency is improved.

(2) Since the AND operator priority process is not completely deleted but is selected as the process priority function, the search function can be selected and executed according to the situation.

(3) Since the processing level setting function is introduced, AND priority processing, OR priority processing, or processing in that case, and various searches can be realized.

[Brief description of drawings]

FIG. 1 is a functional configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flow chart for creating a conditional expression used in the present invention.

FIG. 3 is a search execution flow of the present invention.

FIG. 4 is a conventional search processing flow.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Operator determination means 2 ... Processing priority means 3 ... Operator type determination means 4 ... Logical OR search means 5 ... Logical product search means 6 ... Database 7 ... Execution determination means 8 ... Display unit

Claims (1)

[Claims] 1. A search device for searching for desired data while executing a logical operation, which is a search command, for data stored in a database, judges whether or not a connection operator of a search condition is defined, and defines it. If not, an operator determining means for executing a single condition search, a processing priority means for determining whether or not a processing priority level is set when the operator is present, and processing is performed in descending order of priority level when the operator is set, A type discriminating means for executing the type judgment of the logical product sum of the operators, and the arithmetic expression left side condition is searched from the database when the logical sum is judged by the discriminating means, and when the left side condition is retrieved, the arithmetic expression right side condition is stored in the database. And the type discriminating means searches the database for the left side condition of the arithmetic expression, and when the left side condition has been searched, the right side condition is searched. An AND search means for performing a search from the result of the times search, and an execution determining means for determining whether or not all the operation conditions are completed, executing the processing by the processing priority means when not completed, and displaying the search result at the end. A search device in a database system characterized by being provided.