What are the main requirements for designing and using SQL databases that you know?

Main requirements for designing and using SQL databases:

• Data normalization — structuring tables to minimize redundancy and ensure integrity.
• Indexing — creating indexes to speed up searches and queries.
• Security — using parameterized queries to prevent SQL injection.
• Transactions — ensuring atomicity of operations to maintain data integrity.
• Backup and recovery — regularly creating backups.
• Query optimization — analyzing and improving query performance.

In Go, the database/sql package is usually used for working with SQL, along with drivers like pq for PostgreSQL. An example of a safe query:

stmt, err := db.Prepare("SELECT * FROM users WHERE email = ?")
if err != nil {
    log.Fatal(err)
}
rows, err := stmt.Query(userEmail)

Parameters are passed separately here, which protects against injections.