Method and system for database join disambiguation
AssigneeInternational Business Machines Corporation
InventorsCharles Mike Potter, Glen Michael Seeds, Henk Cazemier
Life of this patent
Estimating the term…
Abstract
In cases where two or more database tables can be joined by more than one relationship or criterion on the row values of selected columns, to produce what is effectively a wider table, there may result an ambiguity of which join should be used. The invention provides a means of join disambiguation that is rule-driven. The user is relieved of understanding the details of how the disambiguation is being done. The system described in this invention makes the choice of which join to use based on clear transformation rules which relate to folders of the tables and their relationships.
Claims15
A method for accessing values in a database and creating a report comprising the following steps:
- accepting from a user an indication of the elements required in a report;
- creating a set of one or more database queries required to produce the report;
- disambiguating each database query in the set automatically by creating a model of the necessary query subjects, with their related query items and relationships thereby defining a set of transformation rules for the database that permits automatic disambiguation;
- applying the set of disambiguated database queries to the database using the transformation rules;
- and
- creating the report based on the results of the set of database queries.
A system for accessing values in a database and creating a report comprising:
- means for accepting from a user an indication of the elements required in a report;
- means for creating a set of one or more database queries required to produce the report;
- means for disambiguating each database query in the set automatically by creating a model of the necessary query subjects, with their related query items and relationships, and defining a set of transformation rules for the database thereby permitting automatic disambiguation;
- means for applying the set of disambiguated database queries to the database using the transformation rules;
- and
- means for creating the report based on the results of the set of database queries.
A computer program product comprising a computer useable medium having computer readable program code embodied therein for the disambiguation of relationships comprising:
- computer readable program code devices configured to cause a computer to accept from the user an indication of the elements required in a report;
- computer readable program code devices configured to cause a computer to create a set of database queries required to produce the report;
- computer readable program code devices configured to cause a computer to disambiguate each database query in the set automatically by creating a model of the necessary query subjects, with their related query items and relationships thereby defining a set of transformation rules for the database that permits automatic disambiguation;
- computer readable program code devices configured to cause a computer to apply the database queries to the database using the transformation rules;
- and
- computer readable program code devices configured to cause a computer to create the report based on the results of the database queries.
Dependencies are inferred from the claim text.