Declarative Objectivity (DO) Language : Data Statements
Data Statements
Data statements are the functional units of the DO language that enable you to work with data stored in a federated database.
A statement is an instruction that performs an action and, in most cases, returns a value. A statement starts with a keyword, contains one or more data clauses, and ends with a semicolon.
Returns objects (or values projected from objects) selected from the query source.
Performs a graph query by matching a pattern that describes vertices and edges representing interconnected data.
Creates new objects in the data store.
Deletes existing objects from the data store.
Updates an attribute value of existing objects in the data store.
Defines a parameter (named value) that can be used in another statement.
Evaluates an expression and displays the result.
Lists the parameters currently defined by previous LET statements.
Note:Examples in the data-statement topics are based on the Rental Fleet Sample Schema.
Note:These statements work with persistent data. For statements that work with a federated database’s schema, see Schema Statements.