Android中SQLite数据库中的单行

Question

I am having the darnest time trying to grab a row by ID from my database and can't figure out why it isn't working.

In my DatabaseHelper Class I have this snippet of code

public Cursor getData(String Id) {

        SQLiteDatabase db = this.getWritableDatabase();
        Cursor res = db.rawQuery("select * from " + BirdDB.BIRD_TABLE + "Where BIRD_ID = ?", new String[]{Id});
        return res;

    }

Col_0 is the ID of the bird in the table. This is what I have in my activity page.

public void viewASingle() {
        viewABird.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Cursor res = MainActivity.myDB.getData(txt_Id.getText().toString());
                        if (res.getCount() == 0) {

                            showMessage("Error", "Nothing Found");
                            return;
                        }
                        StringBuffer buffer = new StringBuffer();
                        while (res.moveToNext()) {

                            buffer.append("ID :" + res.getString(0) + "\n");
                            buffer.append("Name : " + res.getString(2) + "\n");
                            buffer.append("Notes : " + res.getString(3) + "\n");
                            buffer.append("Location : " + res.getString(4) + "\n");
                            buffer.append("Date And Time : " + res.getString(5) + "\n");
                        }

                        showMessage("Data", buffer.toString());
                    }
                }
            );
    }

So I made sure the rest of the code is working and it is by toast messages. The app crashes with the rawQuery statement and I believed I was doing it right. I did check out other stack overflow questions and tried their statements but alas no avail. So any idea from someone?

Answer 1

Before the concatenation of "Where BIRD_ID = ?" leave a space, so the table's name doesn't stick on to the condition. Also I suggest using exception handling, it will help you debugging and also make your programs more stable