Business Analyst: What is a data validation rule?

Data validation rule — criteria for accepting data.

Types:

• Format — email, phone pattern.
• Range — min/max values.
• Presence — required fields.
• Uniqueness — no duplicates.
• Cross-field — related fields.

Example:

Implementation:

• Front-end validation.
• Back-end validation.
• Database constraints.

BA role: Define validation rules in requirements.