Method for retrieving data from a database
AssigneeOracle International Corporation
InventorsRobert Lavender, James Lear
Life of this patent
Estimating the term…
Abstract
A method of generating a SQL statement for retrieving a data set from a database via a user interface and a database server and then processing the data set recursively. The method comprises the following steps: a) inputting a nested n-pass expression to the user interface in a form that the database server cannot execute; and b) converting the nested n-pass expression into a SQL statement that the database server can execute, the SQL statement having a level of recursion for each level of nesting of the n-pass expression, each level of recursion operating in use on the results of at least one of the preceding levels.
Claims12
A method of generating a SQL statement for retrieving a data set from a database via a user interface and a database server and then processing the data set recursively, the method comprising the following steps:
- a) inputting a nested n-pass expression to the user interface in a form that the database server cannot execute, wherein an n-pass expression is an analytic expression that specifies data to be retrieved from the database and then processed in a plurality of passes, and wherein the nested n-pass expression comprises at least one n-pass expression that references at least one other n-pass expression, and wherein each n-pass expression indicates data that is to be retrieved from the database and processed in a plurality of passes;
- and
- b) converting the nested n-pass expression into a SQL statement that the database server can execute, the SQL statement having a level of recursion for each level of nesting of the n-pass expression, each level of recursion operating in use on the results of at least one of the preceding levels.
Apparatus for generating a SQL statement for retrieving a data set from a database and then processing it recursively, the apparatus comprising at least one store for storing the database, a database server, input means and a processor, the processor being adapted to execute a program for:
- a) receiving a nested n-pass expression from the input means in a form that the database server cannot execute;
- and
- b) converting the nested n-pass expression into a SQL statement that the database server can execute;
- wherein an n-pass expression is an analytic expression that specifies data to be retrieved from the database and then processed in a plurality of passes, and
- wherein the nested n-pass expression comprises at least one n-pass expression that references at least one other n-pass expression, and wherein each n-pass expression indicates data that is to be retrieved from the database and processed in a plurality of passes.
Dependencies are inferred from the claim text.