How to implement authentication and authorization for SQL database access in Go?

To implement authentication and authorization for SQL database access in Go, you can follow these steps:

Import the necessary packages:

import (
    "database/sql"
    _ "github.com/go-sql-driver/mysql"
)

Create a function to establish a connection with the database:

func connectToDB() (*sql.DB, error) {
    db, err := sql.Open("mysql", "username:password@tcp(127.0.0.1:3306)/dbname")
    if err != nil {
        return nil, err
    }
    return db, nil
}

Replace username, password, and dbname with the appropriate values.

Create a function to authenticate the user:

func authenticateUser(username, password string) (bool, error) {
    db, err := connectToDB()
    if err != nil {
        return false, err
    }
    defer db.Close()

    var count int
    err = db.QueryRow("SELECT COUNT(*) FROM users WHERE username=? AND password=?", username, password).Scan(&count)
    if err != nil {
        return false, err
    }

    return count > 0, nil
}

Assuming you have a users table in your database with username and password columns.

Create a function to authorize the user:

func authorizeUser(username, role string) (bool, error) {
    db, err := connectToDB()
    if err != nil {
        return false, err
    }
    defer db.Close()

    var count int
    err = db.QueryRow("SELECT COUNT(*) FROM user_roles WHERE username=? AND role=?", username, role).Scan(&count)
    if err != nil {
        return false, err
    }

    return count > 0, nil
}

Assuming you have a user_roles table in your database with username and role columns.

Use the authentication and authorization functions in your application:

func main() {
    authenticated, err := authenticateUser("user123", "password123")
    if err != nil {
        panic(err)
    }

    if !authenticated {
        // Handle unauthorized access
    }

    authorized, err := authorizeUser("user123", "admin")
    if err != nil {
        panic(err)
    }

    if !authorized {
        // Handle unauthorized access
    }

    // Proceed with database operations
}

Replace "user123" and "password123" with the actual username and password values.

By following these steps, you can implement authentication and authorization for SQL database access in your Go application.