我正在創建一個應用程序(使用Java和SQLite)(JFrame，使用Netbeans)我有我想要登錄的用戶 . (我有所有正確的包JDBC，SQLite等)
我遇到的問題似乎是獲取用戶名/密碼來檢查我的users.db文件..我正在使用Java和SQLite . 我也在使用JDBC .
我的一些代碼作為一個例子(這發送我的用戶信息來創建帳戶，工作正常)，我的數據庫是users.db，我想比較USERNAME＆PASSWORD的用戶名/密碼
Connection dbconn = null;
Statement stmt = null;
String query = "insert into USERS(ID, FIRSTNAME, SECONDNAME, USERNAME, PASSWORD, JAVALESSON, CLESSON, PYTHONLESSON) values(?, ?, ?, ?, ?, ?, ?, ?)";
try {
Class.forName("org.sqlite.JDBC");
dbconn = DriverManager.getConnection("jdbc:sqlite:users.db");
Statement statement = dbconn.createStatement();
PreparedStatement pstmt = dbconn.prepareStatement(query);
我有一個UsernameLoginBox和PasswordLoginBox，如何根據文本框中的字符串檢查USERNAME＆PASSWORD(來自SQLite數據庫)以進行登錄？
經過審查的代碼：
Connection conn = null;
ResultSet rs =null;
PreparedStatement pst =null;
String sql1 = "Select * from USERS where USERNAME=? and PASSWORD=?";
try{
pst = conn.prepareStatement(sql1);
pst.setString(1, UsernameLogIn.toString());
pst.setString(2, PasswordLogInField.getText());
rs=pst.executeQuery();
if(rs.next()){
JOptionPane.showMessageDialog(null, "Username & Password are correct");
} else {
JOptionPane.showMessageDialog(null, "Username & Password are incorrect");
System.out.println("Logged in");
}
}
catch(Exception e){
JOptionPane.showMessageDialog(null, e);
System.out.println("Not Logged in");
}
還有這個：
Connection cbconn = null;
Statement stmt2 = null;
String upcheck = "SELECT USERNAME, PASSWORD FROM USERS";
ResultSet rs = Statement.executeQuery(upcheck);
while (results.next()) {
String staffname = results.getString("snameeee");
String password = results.getString("SPwd");
if ((f.equals(staffname)) && (s.equals(password))) {
JOptionPane.showMessageDialog(null, "Username and Password exist");
}else {
//JOptionPane.showMessageDialog(null, "Please Check Username and Password ");
}
results.close();
} catch (SQLException sql) {
out.println(sql);
