java.lang.IllegalArgumentException:column'；foo'；android不存在

许多StackOverflow问题与此类似，但这不是查询字符串中的间距不正确的问题。我有两个表，一个用于对等方，另一个用于消息，其中外键与对等表中的ID关联

以下是我的创建字符串：

private static final String DATABASE_CREATE = "CREATE TABLE " + PEER_TABLE + " ("
        + PeerContract._ID    + " INTEGER PRIMARY KEY, "
        + PeerContract.NAME + " TEXT NOT NULL, "
        + PeerContract.ADDRESS  + " TEXT NOT NULL, "
        + PeerContract.PORT + " TEXT NOT NULL);";

private static final String MESSAGE_TABLE_CREATE = "CREATE TABLE " + MESSAGE_TABLE + " ("
        + MessageContract._ID + " INTEGER PRIMARY KEY, "
        + MessageContract.MESSAGE_TEXT  + " TEXT NOT NULL, "
        + MessageContract.SENDER + " TEXT NOT NULL, "
        + MessageContract.PEER_FOREIGN_KEY + " INTEGER NOT NULL, "
        + "FOREIGN KEY ("+ MessageContract.PEER_FOREIGN_KEY+") " +
        "REFERENCES "+PEER_TABLE+"("+PeerContract._ID+") ON DELETE CASCADE);";
private static final String CREATE_INDEX =  "CREATE INDEX " + INDEX + " ON " +
        MESSAGE_TABLE + "(" + MessageContract.PEER_FOREIGN_KEY + ");";

我想查询所有已接收邮件的列表，因此我执行了以下操作：

public Cursor fetchAllMessages(){
    String query = "SELECT " + MESSAGE_TABLE + "." + MessageContract._ID + ", "
            + MessageContract.MESSAGE_TEXT + ", "
            + MessageContract.SENDER
            + " FROM " + MESSAGE_TABLE + " JOIN " + PEER_TABLE + " ON "
            + MESSAGE_TABLE + "." + MessageContract.PEER_FOREIGN_KEY
            + "=" + PEER_TABLE + "." + PeerContract._ID;
    return db.rawQuery(query, null);
}

这对我来说很有意义。到目前为止，间距还可以，没有误差

在我的主要活动中，我有一个SimpleCorsorAdapter：

   listView = (ListView) findViewById(R.id.msgList);
    dbAdapter = new ServerDbAdapter(this);
    dbAdapter.open();
    String[] from = new String[] {PeerContract.NAME, MessageContract.MESSAGE_TEXT};
    int[] to = new int[] {android.R.id.text1, android.R.id.text2};
    cursorAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_2, cursor, from, to);
    listView.setAdapter(cursorAdapter);
    cursor = dbAdapter.fetchAllMessages();
    cursorAdapter.swapCursor(cursor);

我得到“列'名称'不存在”，这让我发疯！

---

我在数据库中正确地将其定义为PeerContract.NAME。我猜这是因为fetchAllMessages发生的，但我不确定如何修复它。

您没有在

fetchAllMessages（）

方法中选择

PeerContract.NAME，MessageContract.MESSAGE\u TEXT

。将其更改为：

public Cursor fetchAllMessages(){
    String query = "SELECT " + MESSAGE_TABLE + "." + MessageContract._ID + ", "
            + MessageContract.MESSAGE_TEXT + ", "
            + PeerContract.NAME + ", "
            + PeerContract.MESSAGE_TEXT + ", "
            + MessageContract.SENDER 
            + " FROM " + MESSAGE_TABLE + " JOIN " + PEER_TABLE + " ON "
            + MESSAGE_TABLE + "." + MessageContract.PEER_FOREIGN_KEY
            + "=" + PEER_TABLE + "." + PeerContract._ID;
    return db.rawQuery(query, null);
}

---

成功了！！！现在说得通了，但我坚持了好几个小时。正如您所知，我对sqlite仍然非常陌生。你是个圣人，很高兴我能帮你！每个人都曾经是初学者：）学习愉快！