Using cursor to retrieve one row of data (all entries from one id)

Question

I'm starting my first trip into sqlite databases in an Android app, so far I can add to a database, I can update an entry in a database and I can display every bit of data in a database, but what I'm stuck with is how to get one entry (well one id and all its associated rows).

To retrieve all the rows I use this code

Database helper:

public Cursor getAllData() {
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor res = db.rawQuery("select * from "+table_name,null);
    return res;
}

and to call it in my activity class

public void viewallFunction() {
        Cursor res = characterDB.getAllData();

        if(res.getCount() == 0) {
            showmessage("Error","no Data");
            return;
        } else {
            StringBuffer buffer = new StringBuffer();

            while (res.moveToNext()) {
                buffer.append("Internal ID : " + res.getString(0) + "\n");
                buffer.append("Player Name : " + res.getString(1) + "\n");
                buffer.append("Character Name : " + res.getString(2) + "\n");
                buffer.append("NickName : " + res.getString(3) + "\n");
                buffer.append("Alignment : " + res.getString(4) + "\n");
                buffer.append("Race : " + res.getString(5) + "\n");
            }

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

when called this works great (there's actually 81 entries so res.getString(0) all the way to res.getString(80) the functions trimmed for this post)

From what I understand the * in:

Cursor res = db.rawQuery("select * from " + table_name, null);

means all columns.

So I created this method in my database helper :

public Cursor getOneData(int id) {
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor res = db.rawQuery("select "+id+" from "+table_name,null);
    return res;
}

and called it with

public void getOneId(int id) {
    Cursor res = characterDB.getOneData(id);

    if(res.getCount() == 0){showmessage("Error","no Data");
        return;}
    else{
        showmessage("test","retreived id "+res.getString(0)+" which is "+res.getString(1));
        displaySheet(res.getString(0),
                res.getString(1),
                res.getString(2),
                res.getString(3),
                res.getString(4),
                res.getString(5),
        );}
}

Again that's trimmed for this post, display sheet then deals with the data, however nothing happens, i do not get either of the messages (which I'm sure is an impossibility, one or the other should display!) I do not get any errors either, just nothing happens, at first i thought the method was not even firing but I rewrote it to:

public void getOneId(int id){
    showmessage("Message","id is "+id);
}

and the test message showed perfectly

It has me completely stumped, a few hours of googling has got me more confused, each example i see is tailored very specifically to the app being made and looks nothing remotely like my code, which if the all display method didn't work I would say ah ha there's my problem, but my all display method does work...and well that's how I have learned it over the last 3 or 4 days (oh god please tell me I'm not doing it wrong)

So yeah what am I doing wrong?

How am I meant to retrieve one row as a set of strings?

For reference the first column in the table is set as

ID INTEGER PRIMARY KEY AUTOINCREMENT

not sure if that's relevant or not though

EDIT: the database is structured like so:

1 "david" "zarr" "the great" "choatic" "human"
2 "george" "tod" "toddy" "lawful" "elf"

ie:

int string string string string string

The column names being :

ID   PLAYERNAME   CHARNAME   NICKNAME   RACE

The goal I'm trying to achieve is to use that id row to retrieve the strings (which I then change edittext's to, that part I know, but it's getting those strings that I can't suss out)

Ideally I just want to say to the database, give me all the strings from the row with id 1 and the database to say here you are their "david" "zarr" "the great" "choatic" "human"

ok the answer came from Pitty

A change of the database geto one method to :

    public Cursor getOneData(int id){
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor res = db.rawQuery("select * from "+table_name+" WHERE ID='" + id + "'",null);
    return res;
}

and a change of the method i was using to call it :

    public void getOneId(int id){
    Cursor res = characterDB.getOneData(id);
    if(res.getCount() == 0){showmessage("Error","no Data");
        return;}
    else{


        if (res != null && res.moveToFirst()); do {
        showmessage("test","retreived id "+res.getString(0)+" which is "+res.getString(1));
        displaySheet(res.getString(0),
                res.getString(1),
                res.getString(2),
                res.getString(3),
                res.getString(4),
                res.getString(5),
        ); } while (res.moveToNext()); }

}

Answer 1

You are fetching Id column in your query and you want entire one row for that Use this :

public Cursor getOneData(int id){
SQLiteDatabase db = this.getWritableDatabase();
Cursor res = db.rawQuery("select * from "+table_name+" WHERE id='" + id + "'",null);
if (res != null && res.moveToFirst()) { 
do { 
    //Call Your Function
   } 
while (res.moveToNext()); 
}
 return res;
 }