从数据库表读取数据并在Android Studio

Question

我想将我的联系人导出到android studio中的Excel文件。现在我访问我的联系人并将它们保存到Sqlite中的表中。我还有一个导出按钮，用于将我的数据导出到excel文件。但是如何查询我的表并将结果写入Excel文件？

btnExport.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View v) {

        CSVWriter writer = null;
        try
        {
            //read from db
            mydb=openOrCreateDatabase(DbName,Context.MODE_PRIVATE,null);
            Cursor crs=  mydb.rawQuery("Select * from tblContact",null);

            String[] array = new String[crs.getCount()];
            int i = 0;
            writer = new CSVWriter(new FileWriter("/sdcard/myfile.csv"), ',');

            while(crs.moveToNext()) {
                String uname = crs.getString(crs.getColumnIndex("FirstName"));
                array[i] = uname;
                i++;
                writer.writeNext(new String[]{array[i]});
            }
            writer.close();
            Toast.makeText(getApplicationContext(),"Exported",Toast.LENGTH_LONG).show();
            mydb.close();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }
});