Sql Server Data Tools [updated] ✔

But when she deployed to a pre-production staging environment that mirrored production data, disaster struck. The deployment failed with a bizarre error: “Cannot insert NULL into column ‘NewColumn’.” But the column definition had a DEFAULT value of GETDATE() ! How could it try to insert NULL?

One Friday afternoon, a junior developer was tasked with a seemingly simple change: add a new NOT NULL column to a fact table called FactTransactions . Following standard practice, she opened the SSDT project, added the column to the table definition, and hit “Publish.” SSDT helpfully generated the deployment script, showing a standard ALTER TABLE ADD command. She deployed to the development environment—no issues. Then to QA—fine. sql server data tools

The fix? They learned that for large tables with a NOT NULL column and a default, SSDT’s “smart” offline deployment strategy (which avoids online ALTER operations that could lock the table for hours) backfires. They had to change the deployment settings: disable the “allow offline deployments” or explicitly tell SSDT to use an online ALTER TABLE ADD WITH VALUES command. But when she deployed to a pre-production staging

The story became a legend in their team: “Always review the actual generated deployment script before publishing—never trust the visual diff.” And they added a mandatory step to their CI/CD pipeline: generate the script, inspect it for hidden table rebuilds, then deploy. One Friday afternoon, a junior developer was tasked