Question

我有下表

private static final String DB_TABLE = "create table user (id integer primary key autoincrement, " 
                                            + "username text not null, password text not null, tel text not null, info text not null, job text);";

如何使用游标获取数据并将其转换为字符串？因为我得到null我应该设置得到吗？我必须通过用户名和密码获取工作和信息吗？

Cursor theUser = dbHelper.fetchUser(thisUsername, thisPassword);
   if (theUser != null) {

// How here also fetch a info and job in String?

            startManagingCursor(theUser);
            if (theUser.getCount() > 0) {
                //saveLoggedInUId(theUser.getLong(theUser.getColumnIndex(DatabaseAdapter.COL_ID)), thisUsername, thePassword.getText().toString());
                stopManagingCursor(theUser);
                theUser.close();
               // String text = dbHelper.getYourData();
                Intent i = new Intent(v.getContext(), InfoActivity.class);
                startActivity(i);
            }

            //Returns appropriate message if no match is made
            else {
                Toast.makeText(getApplicationContext(),
                        "You have entered an incorrect username or password.",
                        Toast.LENGTH_SHORT).show();
               // saveLoggedInUId(0, "", "");
            }
            stopManagingCursor(theUser);
            theUser.close();
        }

        else {
            Toast.makeText(getApplicationContext(),
                    "Database query error",
                    Toast.LENGTH_SHORT).show();
        }
    }

private static final String LOGIN_TABLE = "user";
    //Table unique id
    public static final String COL_ID = "id";
    //Table username and password columns 
    public static final String COL_USERNAME = "username";
    public static final String COL_PASSWORD = "password";
    private static final String KEY_PHONE = "tel";
    private static final String INFO = "info";
    private static final String JOB = "info";

public Cursor fetchUser(String username, String password) {
    Cursor myCursor = database.query(LOGIN_TABLE, 
            new String[] { COL_ID, COL_USERNAME, COL_PASSWORD }, 
            COL_USERNAME + "='" + username + "' AND " + 
            COL_PASSWORD + "='" + password + "'", null, null, null, null);

    if (myCursor != null) {
        myCursor.moveToFirst();
    }
    return myCursor;
}

提前谢谢!!!

更新：

String name = theUser.getString(theUser.getColumnIndex(DatabaseAdapter.COL_USERNAME));
String phone = theUser.getString(theUser.getColumnIndex(DatabaseAdapter.KEY_PHONE));
String tel = theUser.getString(theUser.getColumnIndex(DatabaseAdapter.KEY_PHONE));
String info = theUser.getString(theUser.getColumnIndex(DatabaseAdapter.INFO));
String job = theUser.getString(theUser.getColumnIndex(DatabaseAdapter.JOB));
String id = theUser.getString(theUser.getColumnIndex(DatabaseAdapter.COL_ID));

我如何写这个请求：

public Cursor fetchAllUsers() {
    return database.query(LOGIN_TABLE, new String[] { COL_ID, COL_USERNAME, 
            COL_PASSWORD }, null, null, null, null, null);
}

Answer 1

要在各个数据行之间移动，您可以使用moveToFirst()和moveToNext()方法。 isAfterLast()方法允许检查是否已到达查询结果的末尾。

Cursor提供了键入的get*()方法，例如getLong(columnIndex)，getString(columnIndex)访问结果当前位置的列数据。＆＃34; columnIndex＆＃34;是您要访问的列的编号。

Cursor还提供getColumnIndexOrThrow(String)方法，该方法允许获取表的列名的列索引。

完成后，需要使用close()方法调用关闭Cursor。

您的代码应该看起来像这样以获取信息列，但请在您的问题中注意JOB和INFO列具有相同的字符串，因此他们将返回相同的列索引，直到您修复

String info = theUser.getString(theUser.getColumnIndex(DatabaseAdapter.INFO))

从sqlite android获取数据

1 个答案: