sqlcmd

Use sqlcmd only when a repository recipe does not already cover the diagnostic. Prefer repo-local commands such as just db-test, make test-db, migration recipes, or integration tests when they exist.

Safety Defaults

• Prefer a test, development, or disposable database. Never run write or destructive diagnostics against production.
• Load connection settings from the repo's environment mechanism; do not hardcode passwords, hosts, ports, or database names.
• Use read-only queries unless the user or test recipe explicitly requires writes.
• Include -b in scripts when SQL errors should fail the command.
• Use -C only for trusted local containers or environments where the repo documents self-signed certificates.
• Redact secrets from output.

Invocation Pattern

Adapt the variable names to the repo's .env, secrets manager, or wrapper script:

sqlcmd \
  -S "$DB_HOST,$DB_PORT" \
  -U "$DB_USER" \
  -P "$DB_PASSWORD" \
  -d "$DB_NAME" \
  -C \
  -Q "select @@VERSION"

If the repo uses an env wrapper, place sqlcmd inside that wrapper instead of exporting secrets in your shell.

Quoting Rules

• Wrap the whole SQL batch passed to -Q in shell double quotes so environment variables can expand outside the SQL.
• Use SQL single quotes for string literals inside the batch: where Name = 'Example'.
• Do not use shell-escaped double quotes as SQL string literals; SQL Server may interpret them as identifiers.
• For multi-statement or hard-to-quote probes, prefer a repo-local scratch file only when the repo allows temporary files. Delete the scratch file afterward.

Useful Recipes

Run a tSQLt class:

sqlcmd -S "$DB_HOST,$DB_PORT" -U "$DB_USER" -P "$DB_PASSWORD" -d "$DB_NAME" -C -b \
  -Q "exec tSQLt.Run 'test_ExampleProcedure'"

Return compact scalar output:

sqlcmd -S "$DB_HOST,$DB_PORT" -U "$DB_USER" -P "$DB_PASSWORD" -d "$DB_NAME" -C -h-1 -W \
  -Q "set nocount on; select count(*) from sys.tables"

Inspect object columns:

sqlcmd -S "$DB_HOST,$DB_PORT" -U "$DB_USER" -P "$DB_PASSWORD" -d "$DB_NAME" -C -h-1 -W \
  -Q "set nocount on; select c.name, t.name, c.max_length, c.precision, c.scale
      from sys.columns c
      join sys.types t on t.user_type_id = c.user_type_id
      where c.object_id = object_id('dbo.ExampleObject')
      order by c.column_id"

Time a query:

sqlcmd -S "$DB_HOST,$DB_PORT" -U "$DB_USER" -P "$DB_PASSWORD" -d "$DB_NAME" -C \
  -Q "set statistics time on; set nocount on; exec dbo.ExampleProcedure @ExampleID = 1"

Output

Report the command shape, target environment class, result summary, and any uncertainty about whether the diagnostic used the intended database.