Rule Type Column in Database
A data definition language (DDL) may be extended by a new column type: a rule type column. Database rules are modeled using patterns (e.g. decision table, decision tree, or formula) specifying rule content through accessible user interfaces instead of programming constructs. A rule type column can be created using the DDL statements to define its storage type (transient or permanent), and/or whether it is generic or non-generic. A transient rule column will be populated only when a query is performed. A non-transient rule column will be populated when an insert is performed, and may be re-triggered during an update. A generic rule column allows a rule to be defined each time an insert is performed (e.g. each row might trigger a different rule). A non-generic rule column allows initial definition of one rule statically for all rows. The system of rules evaluation can be integrated with the language processor.
1 . A computer-implemented method comprising:
providing in a non-transitory computer readable storage medium, a database created in an application level language and comprising data organized in rows and columns;
expressing a rule modeled from data patterns in the database, in a statement in a data design language, wherein the data patterns reflect the logic of a business rule;
posing a query to the database;
causing the statement in the data design language to communicate with the database to create a rule type column;
deriving a value based on the query and a row intersecting the rule type column; and
displaying the value for the rule type column in response to the query.
2 . The computer-implemented method of claim 1 wherein the value is persisted in the database.
3 . The computer-implemented method of claim 1 wherein the value is not persisted in the database.
4 . The computer-implemented method of claim 1 wherein the rule type column is the same for all of the rows.
5 . The computer-implemented method of claim 1 wherein the rule is expressed at a time of creation of the database.
6 . The computer-implemented method of claim 1 wherein the rule is expressed at a time of an insert or update operation.
7 . A non-transitory computer readable storage medium embodying a computer program for performing a method, said method comprising:
providing a database created in an application level language and comprising data organized in rows and columns;
expressing a rule modeled from data patterns in the database, in a statement in a data design language, wherein the data patterns reflect the logic of a business rule;
posing a query to the database;
causing the statement in the data design language to communicate with the database to create a rule type column;
deriving a value based on the query and a row intersecting the rule type column; and
displaying the value for the rule type column in response to the query.
8 . The non-transitory computer readable storage medium of claim 7 wherein the method comprises persisting the value in the database.
9 . The non-transitory computer readable storage medium of claim 7 wherein the method comprises not persisting the value in the database.
10 . The non-transitory computer readable storage medium of claim 7 wherein the method comprises having the rule type column be the same for all of the rows.
11 . The non-transitory computer readable storage medium of claim 7 wherein the method comprises expressing the rule at a time of creation of the database.
12 . The non-transitory computer readable storage medium of claim 7 wherein the method comprises expressing the rule at a time of an insert or update operation.
13 . A computer system comprising:
one or more processors;
a software program, executable on said computer system, the software program configured to:
access in a non-transitory computer readable storage medium, a database created in an application level language and comprising data organized in rows and columns;
express a rule modeled from data patterns in the database, in a statement in a data design language, wherein the data patterns reflect the logic of a business rule;
pose a query to the database;
cause the statement in the data design language to communicate with the database to create a rule type column;
derive a value based on the query and a row intersecting the rule type column; and
display the value for the rule type column in response to the query.
14 . The computer system of claim 13 wherein the software program is configured to persist the value in the database.
15 . The computer system of claim 13 wherein the software program is configured to not persist the value in the database.
16 . The computer system of claim 13 wherein the software program is configured to make the rule type column be the same for all of the rows.
17 . The computer system of claim 13 wherein the software program is configured to express the rule at a time of creation of the database.
18 . The computer system of claim 13 wherein the software program is configured to express the rule at a time of an insert or update operation.