#include <project.h>
Inheritance diagram for Project:
Collaboration diagram for Project:
Public Member Functions | |
| Project (FileId rel_id, FileId result_id, std::vector< FieldId > fields, Catalog *catalog) | |
| Constructor for Project operation. | |
| ~Project () | |
| Destructor for the project Operation. | |
| void | runOperation () |
| Runs the operation. | |
 Public Member Functions inherited from Operation | |
| Operation (FileId result_id, Catalog *catalog) | |
| Constructor for the Operation class. Because Operation is an abstract class, an object cannot be created, but this constructor is used by derived classes. | |
| virtual | ~Operation () |
| Destructor for the Operation class. Cleans up dynamic memory in result state. | |
Protected Attributes | |
| std::vector< FieldId > | fields |
| fileState | file_state |
| Protected Attributes inherited from Operation | |
| fileState | result_state |
| Catalog * | catalog |
Additional Inherited Members | |
| Protected Member Functions inherited from Operation | |
| void | _initState (FileId file_id, std::vector< FieldId > fields, fileState *state) |
| Performs the file and temporary record setup for relational operators. | |
| void | _delState (fileState *file_state) |
| Deletes objects created in relop structs. | |
Detailed Description
Project is a derived class of operation that implements the project operation, which removes some number of columns from a relation.
Constructor & Destructor Documentation
◆ Project()
| Project::Project | ( | FileId | rel_id, |
| FileId | result_id, | ||
| std::vector< FieldId > | fields, | ||
| Catalog * | catalog | ||
| ) |
Constructor for Project operation.
- Parameters
-
rel_id. FileId of the relation file. result_id. FileId of the result file. fields. Vector of field ids for the project operation. catalog. pointer to the catalog of SwatDB
- Precondition
- rel_id is the name of a valid file.
- Postcondition
- private variables have been set accordingly.
Member Function Documentation
◆ runOperation()
|
virtual |
Runs the operation.
- Precondition
- Valid files and parameters have been passed to the contructor.
- Postcondition
- Result file has been populated with all the records of the original relation, with the new schema only consisting of fields that were specified by passing them into the constructor.
Implements Operation.
Member Data Documentation
◆ fields
|
protected |
Fields that will be kept following the execution of the project operation.
The documentation for this class was generated from the following file:
