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我正在尝试从具有表（带有 _id 字段）的数据库中检索游标，但无法创建 simplecursoradapter 错误说

  SqlliteException: no such column: _id

但是我的数据库类有什么问题：

//The columns we'll include in the dictionary table
public static final String COLUMN_ID = "_id";
public static final String COL_WORD = "WORD";
public static final String COL_DEFINITION = "DEFINITION";


private static final String FTS_TABLE_CREATE =
                "CREATE VIRTUAL TABLE " + FTS_VIRTUAL_TABLE +
                " USING fts3 (" + COLUMN_ID + " integer primary key autoincrement, " +
                COL_WORD + ", " +
                COL_DEFINITION + ")";

并返回光标

public Cursor getWordMatches(String query, String[] columns) {
    String selection = COL_WORD + " MATCH ?";
    String[] selectionArgs = new String[] {query+"*"};

    return query(selection, selectionArgs, columns);
}

private Cursor query(String selection, String[] selectionArgs, String[] columns) {
    SQLiteQueryBuilder builder = new SQLiteQueryBuilder();
    builder.setTables(FTS_VIRTUAL_TABLE);

    String[] col = new String[] {COLUMN_ID, COL_WORD};
    //ubacio null - col
    Cursor cursor = builder.query(mDatabaseOpenHelper.getReadableDatabase(),
            col, selection, selectionArgs, null, null, null);

    if (cursor == null) {
        return null;
    } else if (!cursor.moveToFirst()) {
        cursor.close();
        return null;
    }
    return cursor;
}

这是我显示 ListView 的活动

          //query the db class method getWordMatches()
      Cursor c = db.getWordMatches(query, null);
          displayWords(c);

      }
    }


public void displayWords(Cursor c){

    // Creates a new SimpleCursorAdapter
    SimpleCursorAdapter mCursorAdapter = new SimpleCursorAdapter(
        getApplicationContext(),                    // The application's Context object
        android.R.layout.simple_list_item_1,        // A layout in XML for one row in the ListView
        c,                                          // The result from the query
        new String[] {DatabaseTable.COL_WORD},      // A string array of column names in the cursor
        new int[] { android.R.id.text1 });          // An integer array of view IDs in the row layout


    // Sets the adapter for the ListView
    setListAdapter(mCursorAdapter);

}

该教程来自http://developer.android.com/training/search/search.html

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2 回答 2

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您需要使用别名将 FTS' 更改rowid为 Android 的_id：

String[] col = new String[] {"rowid as " + COLUMN_ID, COL_WORD};

FTS 不允许您覆盖主键的默认列名，因为"integer primary key autoincrement"它被完全忽略为“语法糖”。事实上，FTS 只是将您的_id列解释为通用列......

所以你应该_id从你的 create-table 语句中删除，否则它会添加一个额外的_id列：

private static final String FTS_TABLE_CREATE =
            "CREATE VIRTUAL TABLE " + FTS_VIRTUAL_TABLE +
            " USING fts3 (" + COL_WORD + ", " + COL_DEFINITION + ")";
于 2013-02-22T21:49:01.123 回答
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作为 CursorAdpater 类的要求，基础 Cursor 对象必须包含名为“_id”的列，这就是您收到该错误的原因。这直接来自 CursorAdapter 文档：http: //developer.android.com/reference/android/widget/CursorAdapter.html

于 2013-02-22T22:27:24.150 回答