致：java.lang.IllegalArgumentException：如果列'_id'不存在 [英] Caused by: java.lang.IllegalArgumentException: column '_id' does not exist

问题描述

我想用光标和列表视图，以显示我的表。但我得到的错误。

 致：java.lang.IllegalArgumentException：如果列'_id'不存在
 

但我没有在我的应用程序申报_id。 有人可以帮我吗？

这是我的code在dbHelper。

 公开光标DataPesanKeluar（）{
    光标C = dba.rawQuery（
             选择 
            + kel_id +，
            + e_chiperteks +，
            + k_nama +，
            + kel_waktu +
            FROM+ tbPesan +INNER JOIN+ tbPesanKeluar +
            开+ tbPesan +。 + p_idpesan +=+ tbPesanKeluar +。 + kel_idpesan +
            INNER JOIN+ tbEnkrip +
            开+ tbPesan +。 + p_idenkrip +=+ tbEnkrip +。 + e_idenkrip +
            INNER JOIN+ tbKontak +
            开+ tbPesan +。 + p_idkontak +=+ tbKontak +。 + k_id，NULL）;
    返回℃;
}
 

这是我的类来显示数据。

  listKeluar =（ListView控件）findViewById（R.id.listKeluar）;

    的String [] keluar = {data.k_nama，data.m_chiperteks，data.kel_waktu};
    INT [] K = {R.id.tNama，R.id.tChiper，R.id.tWaktu};
    光标= data.DataPesanKeluar（）;
    SimpleCursorAdapter keluarAdapter =新SimpleCursorAdapter（这一点，R.layout.baris_keluar，光标，keluar，K）; //这是我的错误
    listKeluar.setAdapter（keluarAdapter）;
    listKeluar.setOnItemClickListener（新OnItemClickListener（）{

        @覆盖
        公共无效onItemClick（适配器视图为arg0，查看ARG1，INT ARG2，长ARG3）{
            光标listCursor =（光标）arg0.getItemAtPosition（ARG2）;
            串idkeluar = listCursor.getString（listCursor.getColumnIndex（data.kel_id））;
            字符串NAMA = listCursor.getString（listCursor.getColumnIndex（data.k_nama））;
            串chiperteks = listCursor.getString（listCursor.getColumnIndex（data.m_chiperteks））;
            串waktu = ​​listCursor.getString（listCursor.getColumnIndex（data.kel_waktu））;
 

解决方案

光标必须包括一个名为_id列或这个类将无法工作。

您可以使用现有的ID也许尝试伪造它：

 光标C = dba.rawQuery（
         选择 
        + kel_id +AS _id
        + kel_id +，
        + e_chiperteks +，
        + k_nama +，
        + kel_waktu +
        FROM+ tbPesan +INNER JOIN+ tbPesanKeluar +
        开+ tbPesan +。 + p_idpesan +=+ tbPesanKeluar +。 + kel_idpesan +
        INNER JOIN+ tbEnkrip +
        开+ tbPesan +。 + p_idenkrip +=+ tbEnkrip +。 + e_idenkrip +
        INNER JOIN+ tbKontak +
        开+ tbPesan +。 + p_idkontak +=+ tbKontak +。 + k_id，NULL）;
 

i want to show my table using cursor and list view. but i got error.

 Caused by: java.lang.IllegalArgumentException: column '_id' does not exist

but i didn't declare _id in my application. can somebody help me?

this is my code in dbHelper.

public Cursor DataPesanKeluar() {
    Cursor c = dba.rawQuery(
            " SELECT "
            + kel_id + ","
            + e_chiperteks + ","
            + k_nama + ","
            + kel_waktu +
            " FROM " + tbPesan + " INNER JOIN " + tbPesanKeluar +
            " ON "  + tbPesan + "." + p_idpesan + "=" + tbPesanKeluar + "." + kel_idpesan +
            " INNER JOIN " + tbEnkrip +
            " ON " + tbPesan + "." + p_idenkrip + "=" + tbEnkrip + "." + e_idenkrip +
            " INNER JOIN " + tbKontak + 
            " ON " + tbPesan + "." + p_idkontak + "=" + tbKontak + "." + k_id , null);
    return c;
}

and this is my class to display data.

listKeluar = (ListView)findViewById(R.id.listKeluar);

    String [] keluar = { data.k_nama, data.m_chiperteks, data.kel_waktu };
    int[] k = { R.id.tNama, R.id.tChiper, R.id.tWaktu };
    cursor = data.DataPesanKeluar();
    SimpleCursorAdapter keluarAdapter = new SimpleCursorAdapter( this, R.layout.baris_keluar, cursor, keluar, k ); //this is my error
    listKeluar.setAdapter(keluarAdapter);
    listKeluar.setOnItemClickListener( new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView arg0, View arg1, int arg2, long arg3) {
            Cursor listCursor = (Cursor) arg0.getItemAtPosition(arg2);
            String idkeluar = listCursor.getString(listCursor.getColumnIndex(data.kel_id));
            String nama = listCursor.getString(listCursor.getColumnIndex(data.k_nama));
            String chiperteks = listCursor.getString(listCursor.getColumnIndex(data.m_chiperteks));
            String waktu = listCursor.getString(listCursor.getColumnIndex(data.kel_waktu));

解决方案

The Cursor must include a column named _id or this class will not work.

You can maybe try to fake it using your existing ID:

Cursor c = dba.rawQuery(
        " SELECT "
        + kel_id + " AS _id,"
        + kel_id + ","
        + e_chiperteks + ","
        + k_nama + ","
        + kel_waktu +
        " FROM " + tbPesan + " INNER JOIN " + tbPesanKeluar +
        " ON "  + tbPesan + "." + p_idpesan + "=" + tbPesanKeluar + "." + kel_idpesan +
        " INNER JOIN " + tbEnkrip +
        " ON " + tbPesan + "." + p_idenkrip + "=" + tbEnkrip + "." + e_idenkrip +
        " INNER JOIN " + tbKontak + 
        " ON " + tbPesan + "." + p_idkontak + "=" + tbKontak + "." + k_id , null);

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