This is pretty straightforward. I ran the command below and it produced the following errors.
The test site was installed using the composer create-project command and the sample data using magento sampledata:deploy.
magento sampledata:reset
Result:
[Zend_Db_Statement_Exception]
SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'module' cannot be null, query was: INSERT INTO `setup_module` (`module`, `data_version`) VALUES (?, ?)
[PDOException]
SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'module' cannot be null
sampledata:reset