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Microsoft SQL Server

Test data in MS SQL Server, including Azure SQL, Synapse Analytics SQL Pool, and Microsoft Fabric.

1. Install​

uv tool install --python python3.11 --upgrade 'datacontract-cli[sqlserver]'

The connection also requires the Microsoft ODBC Driver 18 for SQL Server on your machine. See Installation for pip, pipx, and Docker.

2. Authenticate​

Create a .env file in your working directory (or export the variables):

# .env
DATACONTRACT_SQLSERVER_USERNAME=sa
DATACONTRACT_SQLSERVER_PASSWORD=mysecretpassword
DATACONTRACT_SQLSERVER_TRUST_SERVER_CERTIFICATE=True # for local/dev servers

For Entra ID (Active Directory) authentication modes, see the SQL Server Reference.

3. Create a contract from your tables​

Import the table metadata directly from the database. This also generates a ready-to-test servers block:

datacontract import sqlserver \
  --source localhost \
  --database mydb \
  --schema dbo \
  --table orders \
  --output datacontract.yaml

--source is the host of your SQL Server instance. Add --port if it doesn't listen on the default 1433, repeat --table for multiple tables, or omit it to import every table. --schema defaults to dbo.

Only have a DDL script? datacontract import sql --source orders.sql --dialect sqlserver works too, but writes a servers block with placeholder values that you have to fill in by hand.

4. Test the actual data​

datacontract test datacontract.yaml
Testing datacontract.yaml
Server: production (type=sqlserver, host=localhost, port=1433, database=mydb, schema=dbo)
╭────────┬─────────────────────────────────────────────────┬─────────────────┬─────────╮
│ Result │ Check                                           │ Field           │ Details │
├────────┼─────────────────────────────────────────────────┼─────────────────┼─────────┤
│ passed │ Check that field 'order_id' is present          │ orders.order_id │         │
│ passed │ Check that field order_id has no missing values │ orders.order_id │         │
│  ...   │                                                 │                 │         │
╰────────┴─────────────────────────────────────────────────┴─────────────────┴─────────╯
🟢 data contract is valid. Run 24 checks. Took 3.7 seconds.

5. Let it catch a violation​

The contract becomes valuable when it detects drift. Tighten an expectation — for example, add a quality rule to a schema in datacontract.yaml:

schema:
  - name: orders
    # ...
    quality:
      - type: sql
        description: No order has a negative total
        query: SELECT COUNT(*) FROM orders WHERE order_total < 0
        mustBe: 0

Run datacontract test datacontract.yaml again: every violation is listed as an error, and the command exits with code 1 — ready for CI/CD and scheduled runs so you catch drift before your consumers do.

Reference​

All authentication options (SQL logins, Entra ID modes, az login) and the data type mappings: SQL Server Reference.

Troubleshooting​

  • Can't open lib 'ODBC Driver 18 for SQL Server' — the ODBC driver isn't installed, or its name doesn't match driver in the servers block / DATACONTRACT_SQLSERVER_DRIVER.
  • SSL Provider: certificate verify failed — for servers with self-signed certificates (local Docker, dev), set DATACONTRACT_SQLSERVER_TRUST_SERVER_CERTIFICATE=True.
  • Login failed for user — check the authentication mode: SQL logins need DATACONTRACT_SQLSERVER_AUTHENTICATION=sql (the default); Entra ID users need one of the ActiveDirectory* modes or cli.
  • Could not read model '<table>' — the tables must be in the schema named in the servers block. Without it, the lookup falls back to the login's default schema, usually dbo.