我在azure上托管了一个数据库“ library_db”,该数据库具有一个表“ admin_db”,其字段为“用户名”和“密码”。我如何在Java中检查表中是否存在某个用户? (如果用户已经注册,并且其用户名和密码出现在我的表中)
我尝试了以下方法:
public void LoginAction(String user, String password) {
try {
Connection connection = DriverManager.getConnection(host, username, passwordServer);
SQLServerPreparedStatement preparedStatement = (SQLServerPreparedStatement) connection.prepareStatement("SELECT `username`, `password` FROM `admin_db` WHERE `username`=? AND `password`=?");
preparedStatement.setString(1, user);
preparedStatement.setString(2, password);
SQLServerResultSet resultSet =preparedStatement.executeQuery();
if (resultSet.next()) {
System.out.println("login successful");
}
} catch (Exception e) {
System.out.println("Login fail");
}
代码运行没有错误,但是执行catch-> Output:Login失败
答案 0 :(得分:1)
这是解决方案:
SQLServerPreparedStatement preparedStatement = (SQLServerPreparedStatement)connection.prepareStatement("SELECT username, password FROM admin_db WHERE username=? AND password=?");