检查用户和密码是否存在并返回 true 或 false

Question

I've already created a register system and now i want users to be able to login. So i'm trying to create a function to check if the username and password typed are correct, I'm new to programming and i'm struggling to understand how it should be handled.

I'm using this code:

func sqlLogin(username string, password string, db *sql.DB) bool{
    result, err := db.Query(fmt.Sprintf("SELECT * FROM `users1` WHERE `username` = '%s' and password = '%s'", username, password))
    if err != nil {
        log.Fatal(err)
        return false
    } else {
        fmt.print(result)
        return true
    }

db.query doesn't return different values with this code even if i use correct vs wrong combination. How should i handle it?

Answer 1

I think you want to change your function to be like this, so that you can catch errors from the query even if they're not related to the login failure.

func sqlLogin(username string, password string, db *sql.DB) (bool, error) {
    result, err := db.Query(fmt.Sprintf("SELECT * FROM `users1` WHERE `username` = '%s' and password = '%s'", username, password))
    if err == sql.ErrNoRows {
        return false, nil
    }
    if err != nil {
        fmt.Println(err)
        return false, err
    }
    fmt.Println(result)
    return true, nil
}