คอลัมน์ ชนิดข้อมูล และข้อจำกัด

Every column has a type that decides what it can hold and how the database stores it. Picking the right one keeps data clean. 🎯

Use db.Integer for counts, ids, and ages. It stores whole numbers efficiently and is the usual choice for primary keys.

db.String(120) holds short text and you give it a max length. Use it for names, emails, and titles.

When length is unknown or huge, reach for db.Text. It is ideal for article bodies, comments, and descriptions.

There is a type for most needs: db.Boolean for flags, db.Float for decimals, and db.DateTime for timestamps.

Beyond types, constraints tell the database what is allowed. They protect your data even when your code has a bug.

Set nullable=False to require a value. The database then refuses to save a row that leaves that column empty.

Add unique=True so no two rows share that value. It is perfect for emails or usernames that must stay distinct.

A default fills in a value when you omit one. Great for flags, counters, or a created-at timestamp.

Mark a column with index=True when you filter on it often. The index speeds up searches at a small storage cost.

Options combine freely on one column. Here a field is required, unique, and indexed all at once for a solid email field.

You want to guarantee no two users share an email. Which option do you add?

You matched data to types and added constraints like nullable, unique, default, and index to keep your tables trustworthy. 🛡️