MySQL查询与多个AND运算符

Question

此查询对我不起作用。我哪里做错了。请帮忙

$sql="SELECT * FROM $tbl_name WHERE ( username='$myusername' and (password='$mypassword' and password='$encrypted_mypassword'))";

Answer 1

我假设您接受了普通密码和加密密码。试试这个......

SELECT * FROM $tbl_name WHERE username='$myusername' AND 
(password='$mypassword' OR  password='$encrypted_mypassword')

如果只加密密码，请尝试此操作...

SELECT * FROM $tbl_name WHERE username='$myusername' AND 
password='$encrypted_mypassword'

Answer 2

未经测试，但这应该可行，

$sql="SELECT * FROM $tbl_name WHERE 
Username = '$myusername' AND
Password = '$mypassword' AND
Password = '$encrypted_mypassword'";

对于你正在做的事情，不需要括号，你也试图将一个字段与可能的两个不同的值进行比较。