Displaying ALL data from sqlite database into listview in tabbed activity

Question

I've been struggling with this problem for a few weeks as a novice android developer, and it's getting very exhausting.

I've read through every lesson and question and answer I could find, but I still don't understand how to get Android Studio to just copy the contents of my SQLite database and paste them into a listview. I had assumed there would be some form of android:displayallfrom("myDB") call in the XML files to just show everything in a database, however it seems to be a much more difficult.

Basically, what I want to do is display ALL data from my database (Dogs.db) into my listview (list_dogs) in the first tab of my tab view (Tab1).

Here is my code:

Tab1.java

package com.example.major.awoo;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class Tab1 extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.tab1, container, false);
        return rootView;
    }
}

tab1.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.major.awoo.MainActivity">

    <ListView
        android:id="@+id/list_dogs"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:listSelector=""/>

</RelativeLayout>

DatabaseHelper.java

package com.example.major.awoo;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DatabaseHelper extends SQLiteOpenHelper {
    public static final String DATABASE_NAME = "Dogs.db";
    public static final String TABLE_NAME = "dogs_table";
    public static final String COL_1 = "ID";
    public static final String COL_2 = "NAME";
    public static final String COL_3 = "AGE";
    public static final String COL_4 = "WEIGHT";
    public static final String COL_5 = "BREED";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
            db.execSQL("create table " + TABLE_NAME +" (ID INTEGER PRIMARY KEY AUTOINCREMENT,NAME TEXT,SURNAME TEXT,MARKS INTEGER)");
    }


    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS "+TABLE_NAME);
        onCreate(db);
    }

    public boolean insertData(String name,String age,String weight,String breed) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COL_2,name);
        contentValues.put(COL_3,age);
        contentValues.put(COL_4,weight);
        contentValues.put(COL_5,breed);
        long result = db.insert(TABLE_NAME, null, contentValues);
        if(result == -1)
            return false;
        else
            return true;
    }

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

    public boolean updateData(String id,String name,String age,String weight,String breed) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COL_1,id);
        contentValues.put(COL_2,name);
        contentValues.put(COL_3,age);
        contentValues.put(COL_4,weight);
        contentValues.put(COL_5,breed);
        db.update(TABLE_NAME, contentValues, "ID = ?",new String[] { id });
        return true;
    }

    public Integer deleteData (String id) {
        SQLiteDatabase db = this.getWritableDatabase();
        return db.delete(TABLE_NAME, "ID = ?",new String[] {id});

    }

    public Cursor getListContents(){
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor data = db.rawQuery("SELECT * FROM " + TABLE_NAME,null);
        return data;
}

//method to display data

    public Cursor displayData;
    {
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor res = db.rawQuery(" SELECT  * FROM " + TABLE_NAME, null);
        return res;    
    }   

}

Answer 1

You must create a Dog class if you wish to show all of the information about each dog in a ListView. Even if it is not required, getting data from a database and storing the details of each dog in an instance of the Dog class might simplify your work and make more sense.

public class Dog {
    private String id;
    private String name;
    private String age;
    private String breed;
    private String weight;

    public Dog(String id, String name, String age, String breed, String weight) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.breed = breed;
        this.weight = weight;
    }

    public String getID() {
        return this.id;
    }

    public String getName() {
        return this.name;
    }

    public String getAge() {
        return this.age;
    }

    public String getWeight() {
        return this.weight;
    }

    public String getBreed() {
        return this.breed;
    }
}

The next step is to define an XML layout file that will serve as a representation of each row in your ListView. It can be created however you like.

Here's an example row layout code

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <TextView
        android:id="@+id/text_dogID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="demo"
        android:textColor="#000"
        android:textSize="25sp"/>

    <TextView
        android:id="@+id/text_dogName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="demo"
        android:textColor="#000"
        android:textSize="25sp"
        app:layout_constraintTop_toBottomOf="@id/text_dogID"/>

    <TextView
        android:id="@+id/text_dogAge"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="demo"
        android:textColor="#000"
        android:textSize="25sp"
        app:layout_constraintTop_toBottomOf="@id/text_dogName"/>

    <TextView
        android:id="@+id/text_dogWeight"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="demo"
        android:textColor="#000"
        android:textSize="25sp"
        app:layout_constraintTop_toBottomOf="@id/text_dogAge"/>

    <TextView
        android:id="@+id/text_dogBreed"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="demo"
        android:textColor="#000"
        android:textSize="25sp"
        app:layout_constraintTop_toBottomOf="@id/text_dogWeight"/>

</android.support.constraint.ConstraintLayout>

Finally, you need a method that fills your ListView:

public void fillListview() {
     ListView myListview = findViewById(R.id.myListview);
     DatabaseHelper dbhelper = new DatabaseHelper(this);

     ArrayList<Dog> dogList = dbhelper.getAllData();

     Customadapter myAdapter = new Customadapter(dogList, this);
     myListview.setAdapter(myAdapter);
}