How to retrieve Data from sqlite by user input

Question

Currently I'm developing a small app. I want to retrieve data from sqlite by user input. I have two table Gender_Group and Foods. I want to retrieve data from these tables by user input.
For example app will ask to user to put input field eg Age, Gender to show data according to these fields. When user will insert input, app will show the data according to input field. Can someone help me, how can I write code to implement above functionality.

public class DBClass extends SQLiteOpenHelper {
    private  static  final String dname= "NutritionDatabase";
    private static final int version =4;


    public DBClass(Context context){

        super(context, dname,null, version);
    }

    @Override
    public void onOpen(SQLiteDatabase db){
        super.onOpen(db);
        db.setForeignKeyConstraintsEnabled(true);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        try {
            String gender_cat = "CREATE TABLE  gender_group" +
                    "(id INTEGER PRIMARY KEY," +
                    "name VARCHAR )";
            db.execSQL(gender_cat);

            String foodtbl = "CREATE TABLE Foods" +
                    "(id INTEGER PRIMARY KEY AUTOINCREMENT," +
                    "age VARCHAR ," +
                    "gender_cat INTEGER," +
                    "Food VARCHAR," +
                    "FOREIGN KEY (gender_cat) REFERENCES gender_group(id))";
            db.execSQL(foodtbl);

 InsertGenderCat(1,"Men",db);
            InsertGenderCat(2,"Women",db);
            InsertGenderCat(3,"Toddlers",db);
            InsertGenderCat(4,"Olders",db);     

        insertFoods("12",2,"Calories Required \n 45 to 55 calories per kg.\n\n Protein \n 1 gram per kg. \n\n Breads or Starches. \n 1 bagel or muffin.\n 2 slices bread.\n 1/2 cup cooked cereal, pasta, potatoes, or rice. \n\n Fruits:\n 1/2 cup canned fruit or fruit juice. \n 1 piece fresh fruit, such as an apple, orange, peach, or pear. \n\n 15 to 20 grapes.\n\n Meat or Meat Substitutes:\n 1/2 cup cottage or ricotta cheese. \n 3/4 to 1 cup cooked dried beans or legumes. \n 1 egg.\n 2 to 3 ounces meat, fish, or poultry.\n\n  Milk or Yogurt\n 1 cup  milk or yogurt.\n\n Vegetables:\n 1/2 cup cooked or 1 cup raw vegetable. \n 2 cups salad greens. \n\n Fats\n 6 almonds or 10 peanuts.\n 2 Tbsps cream cheese, avocado, or low calorie salad dressing.\n\nSweets and Desserts .",db);
        insertFoods("13",2,"Calories Required \n 45 to 55 calories per kg.\n\n Protein \n 1 gram per kg. \n\n Breads or Starches. \n 1 bagel or muffin.\n 2 slices bread.\n 1/2 cup cooked cereal, pasta, potatoes, or rice. \n\n Fruits:\n 1/2 cup canned fruit or fruit juice. \n 1 piece fresh fruit, such as an apple, orange, peach, or pear. \n\n 15 to 20 grapes.\n\n Meat or Meat Substitutes:\n 1/2 cup cottage or ricotta cheese. \n 3/4 to 1 cup cooked dried beans or legumes. \n 1 egg.\n 2 to 3 ounces meat, fish, or poultry.\n\n  Milk or Yogurt\n 1 cup  milk or yogurt.\n\n Vegetables:\n 1/2 cup cooked or 1 cup raw vegetable. \n 2 cups salad greens. \n\n Fats\n 6 almonds or 10 peanuts.\n 2 Tbsps cream cheese, avocado, or low calorie salad dressing.\n\nSweets and Desserts .",db);
        insertFoods("14",2,"Calories Required \n 45 to 55 calories per kg.\n\n Protein \n 1 gram per kg. \n\n Breads or Starches. \n 1 bagel or muffin.\n 2 slices bread.\n 1/2 cup cooked cereal, pasta, potatoes, or rice. \n\n Fruits:\n 1/2 cup canned fruit or fruit juice. \n 1 piece fresh fruit, such as an apple, orange, peach, or pear. \n\n 15 to 20 grapes.\n\n Meat or Meat Substitutes:\n 1/2 cup cottage or ricotta cheese. \n 3/4 to 1 cup cooked dried beans or legumes. \n 1 egg.\n 2 to 3 ounces meat, fish, or poultry.\n\n  Milk or Yogurt\n 1 cup  milk or yogurt.\n\n Vegetables:\n 1/2 cup cooked or 1 cup raw vegetable. \n 2 cups salad greens. \n\n Fats\n 6 almonds or 10 peanuts.\n 2 Tbsps cream cheese, avocado, or low calorie salad dressing.\n\nSweets and Desserts .",db);
        insertFoods("15",2,"Total Calories Required \n 40 to 45 calories per kg.\n\n Protein \n 0.9 grams per kg. \n\n Breads or Starches::1/2 cup cottage or ricotta cheese.3/4 to 1 cup cooked dried beans or legumes.\n 1 egg.2 to 3 ounces meat, fish, or poultry.\n  Milk or Yogurt \n 1 cup  milk or yogurt.\n\n Vegetables:\n 1/2 cup cooked or 1 cup raw vegetable.\n 2 cups salad greens.\n\n Fats\n 6 almonds or 10 peanuts.\n 2 Tbsps cream cheese, avocado, or low calorie salad dressing.\n\n Sweets and Desserts .",db);
        insertFoods("16",2,"Total Calories Required \n 40 to 45 calories per kg.\n\n Protein \n 0.9 grams per kg. \n\n Breads or Starches::1/2 cup cottage or ricotta cheese.3/4 to 1 cup cooked dried beans or legumes.\n 1 egg.2 to 3 ounces meat, fish, or poultry.\n  Milk or Yogurt \n 1 cup  milk or yogurt.\n\n Vegetables:\n 1/2 cup cooked or 1 cup raw vegetable.\n 2 cups salad greens.\n\n Fats\n 6 almonds or 10 peanuts.\n 2 Tbsps cream cheese, avocado, or low calorie salad dressing.\n\n Sweets and Desserts .",db);
        insertFoods("17",2,"Total Calories Required \n 40 to 45 calories per kg.\n\n Protein \n 0.9 grams per kg. \n\n Breads or Starches::1/2 cup cottage or ricotta cheese.3/4 to 1 cup cooked dried beans or legumes.\n 1 egg.2 to 3 ounces meat, fish, or poultry.\n  Milk or Yogurt \n 1 cup  milk or yogurt.\n\n Vegetables:\n 1/2 cup cooked or 1 cup raw vegetable.\n 2 cups salad greens.\n\n Fats\n 6 almonds or 10 peanuts.\n 2 Tbsps cream cheese, avocado, or low calorie salad dressing.\n\n Sweets and Desserts .",db);


            }
        catch (SQLException e){
            e.printStackTrace();
        }
}

     private void  InsertGenderCat(Integer id, String group, SQLiteDatabase db){
        ContentValues values = new ContentValues();
        values.put("id",id);
        values.put("name",group);
        db.insert("gender_group", null,values);
    }
    private  void  insertFoods(String age,Integer cat, String food,  SQLiteDatabase db){
     ContentValues values = new ContentValues();

     values.put("age",age);
        values.put("gender_cat",cat);
     values.put("Food",food);
        db.insert("Foods", null,values);
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

            String genderTbl  ="DROP TABLE IF EXISTS gender_categories";
        db.execSQL(genderTbl);
        String foodsTbl  ="DROP TABLE IF EXISTS Foods";
        db.execSQL(foodsTbl);
}
}

Layout File

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:fitsSystemWindows="true"
    android:orientation="vertical">

    <TextView
        android:id="@+id/txtBmr"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Fill The Field  to Find Food"
        android:textAlignment="center"
        android:textColor="@color/colorAccent"
        android:textSize="25dp" />
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:padding="5dp">

        <TextView
            android:id="@+id/food_gender_group"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"

            android:padding="18dp"
            android:text="Gender Group :"
            android:textColor="@color/colorAccent"
            android:textSize="20dp"
            android:textStyle="bold" />

        <EditText
            android:id="@+id/edt_gender_group"
            android:layout_width="289dp"
            android:layout_height="wrap_content"
            android:padding="5dp" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:padding="5dp">

        <TextView
            android:id="@+id/txt_genderGroup_age"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"

            android:padding="18dp"
            android:text="Enter Age :"
            android:textColor="@color/colorAccent"
            android:textSize="20dp"
            android:textStyle="bold" />

        <EditText
            android:id="@+id/edt_genderGroup_age"
            android:layout_width="289dp"
            android:layout_height="wrap_content"
            android:padding="5dp" />
    </LinearLayout>



    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">



    </LinearLayout>

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:padding="5dp"
        android:weightSum="2">

        <Button
            android:id="@+id/btn_food"
            android:textStyle="bold"
            android:padding="5dp"
            android:layout_width="wrap_content"
            android:layout_marginLeft="23dp"
            android:background="@android:color/black"
            android:textColor="@android:color/white"
            android:layout_height="wrap_content"
            android:layout_marginRight="10dp"
            android:textSize="18dp"
            android:layout_weight="1"
            android:text="Click to show Foods"/>



    </LinearLayout>

</LinearLayout>

Answer 1

First, get the two editText value when the button is clicked. Then pass the two values to readEntry function, which is inside DBManager class.

btnFood.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Cursor cursor = dbManager.open().readEntry(genderGroup.getText().toString(), age.getText().toString());
                if (cursor.moveToFirst()) {
                    do {
                        String value = cursor.getString(0);
                        Toast.makeText(getApplication(),value,Toast.LENGTH_SHORT).show();
                    } while (cursor.moveToNext());
                }

            }
        });

Inside DBManager class, write the query in readEntry functionWe can use Left-join query to join two tables.

public class DBManager {

    private DBClass dbhelper;
    private Context context;

    private SQLiteDatabase database;

    public DBManager(Context c) {
        context = c;
    }

    public DBManager open() throws SQLException {
        dbhelper = new DBClass(context);
        database = dbhelper.getWritableDatabase();
        return this;
    }

    public void close() {
        dbhelper.close();
    }


    public Cursor readEntry(String genderGroup, String age) {
        return database.rawQuery("SELECT i.food FROM foods i LEFT JOIN gender_group w ON i.gender_cat = w.id  WHERE w.name = ? AND i.age = ?", new String[]{genderGroup, age}, null);
    } 
}

The output will be displayed as Toast .

You can get full project here: https://github.com/tony123S/ProjectApp