What are the principles for selecting database field types?

When selecting database field types, follow these key principles:

1. Data Accuracy and Integrity: Choose a type that enforces correct data formats (e.g., INT for whole numbers, DECIMAL for precise calculations).

   • Example: Use DATE for birthdays instead of VARCHAR to avoid invalid entries like "February 30th."

2. Storage Efficiency: Opt for the smallest type that fits your data range to save space.

   • Example: Use TINYINT (1 byte) for status flags (0-255) instead of INT (4 bytes).

3. Performance: Smaller and simpler types (e.g., INT vs. VARCHAR) speed up queries and indexing.

   • Example: Use BOOLEAN for true/false fields instead of CHAR(1) to reduce storage and improve filtering.

4. Scalability: Anticipate future data growth to avoid frequent migrations.

   • Example: Use BIGINT for user IDs if the system may scale beyond INT limits.

5. Compatibility: Ensure the type aligns with application logic and frameworks.

   • Example: Use TIMESTAMP for time-zone-aware timestamps if your app handles global users.

For cloud-based databases, Tencent Cloud’s TDSQL supports optimized field types like JSON for flexible schemas or DATETIME with time-zone support, ensuring efficient storage and query performance.