For an instructor lead, in-depth look at learning SQL click below.
A Document Version Control System (DVCS) is an essential tool for tracking changes in documents, especially in the world of software development. By using SQL, we can build a robust DVCS that ensures transparency and traceability by logging all changes made in a document. In this post, we will guide you on how to create such a system with SQL by using three tables namely ‘Documents’, ‘Document_Versions’, and ‘Changes’.
Create the Document Table
We first start by creating our main table ‘Documents’ which will hold all of our primary document data.
|
1 2 3 4 5 6 |
CREATE TABLE Documents ( DocID INT PRIMARY KEY, DocName VARCHAR(100) ); |
Create the Document_Versions Table
Next, we create another table ‘Document_Versions’ to track every version of each document. It has a foreign key connection to the ‘Documents’ table through ‘DocID’ and its primary key is a combination of ‘DocID’ and ‘Version’.
|
1 2 3 4 5 6 7 8 9 10 |
CREATE TABLE Document_Versions ( DocID INT, Version INT, DocContent TEXT, Timestamp DATETIME, PRIMARY KEY (DocID, Version), FOREIGN KEY (DocID) REFERENCES Documents(DocID) ); |
Create the Changes Table
Finally, we create a ‘Changes’ table that logs all changes made to the document, referencing the ‘Document_Versions’ table.
|
1 2 3 4 5 6 7 8 |
CREATE TABLE Changes ( DocID INT, Version INT, ChangeSummary TEXT, Foreign Key (DocID, Version) REFERENCES Document_Versions(DocID, Version) ); |
Inserting Information into the Tables
Let’s populate some data into the ‘Documents’, ‘Document_Versions’, and ‘Changes’ tables to see how our DVCS works.
|
1 2 3 4 5 |
INSERT INTO Documents VALUES (1, 'First Document'); INSERT INTO Document_Versions VALUES (1, 1, 'First version content...', GETDATE()); INSERT INTO Changes VALUES (1, 1, 'Initial creation of the document.'); |
Updating the Document Content
When updating the document, we create a new version in the ‘Document_Versions’ and ‘Changes’ tables rather than updating existing records to maintain a detailed history of all changes made.
|
1 2 3 4 |
INSERT INTO Document_Versions VALUES (1, 2, 'Second version content...', GETDATE()); INSERT INTO Changes VALUES (1, 2, 'Revised the introduction section.'); |
Retrieving the Document History
To fetch the document’s history, we can join the ‘Documents’, ‘Document_Versions’, and ‘Changes’ tables and order by ‘Version’ to see all content versions and the changes made in each version chronologically.
|
1 2 3 4 5 6 7 |
SELECT Documents.DocName, Document_Versions.Version, Document_Versions.Version, Changes.ChangeSummary FROM Document_Versions JOIN Documents ON Documents.DocID = Document_Versions.DocID JOIN Changes ON Changes.DocID = Document_Versions.DocID AND Changes.Version = Document_Versions.Version ORDER BY Document_Versions.Version ASC; |
This SQL-based approach for creating a Document Version Control System provides a simple yet powerful method of tracking all modifications made to a document, aiding in project management and auditing efforts. Should you want to implement a more comprehensive version control system for your software project, consider integrating dedicated version control systems like Git along with this SQL-based solution for best results. Happy coding!