Question

我查询了我的数据库。

public Cursor getCursorSearch(String id_for_listtsk_today) {
    Log.d(Tag, "пытаемся получить курсор для сравнения с гуглом");
    String[] columns = null;
    String selection = null;
    String[] selectionArgs = null;
    String groupBy = null;
    String having = null;
    String orderBy = null;
    //  SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();

    //  queryBuilder.setTables(TABLE_NAME);

    //  String[] asColumnsToReturn = new String[] { COLUMN_ID, COLUMN_NAME,
    //          COLUMN_DATA, COLUMN_STATUS };

    //  Cursor mCursor = queryBuilder.query(dbSqlite, asColumnsToReturn, null,
    //          null, null, null, "title ASC");
    //  Log.d(Tag, "getCursor() получили курсор с базы конец");

    DBHelper dbHelper_AL = new DBHelper(this);  
    final SQLiteDatabase db = dbHelper_AL.getWritableDatabase();
//  final SQLiteDatabase db = this.getWritableDatabase();
    columns = new String[] { DBHelper.COLUMN_ID, DBHelper.COLUMN_NAME, DBHelper.COLUMN_STATUS, DBHelper.COLUMN_TASK, DBHelper.COLUMN_TIME,DBHelper.COLUMN_ACCAUNT, DBHelper.COLUMN_DATA, DBHelper.COLUMN_SELECTED };
    selection = "(name || task ) like  + ? and del != ? ";
    //id_for_listtsk_today = "о";
    selectionArgs = new String[] {"%"+id_for_listtsk_today+"%", Integer.toString(1)};
    orderBy = "time_up";
    Cursor c = db.query("mytable", columns, selection, selectionArgs, null, null, orderBy);
    String[] jbh = MainActivity.logCursor(c);
    Log.d(Tag, "getCursor() получили курсор с базы");
    return c;
}

}

但是野外任务可能为空。当任务等于null时，我的光标数等于0.如何解决？

Answer 1

在SQL中，使用COALESCE选择第一个非null参数。例如：

selection = "(COALESCE(name, '') || COALESCE(task, '')) like ? and del != ? ";

（我还删除了+附近的like。）

喜欢我的查询

1 个答案: