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1public class MainActivity extends AppCompatActivity {
2
3//Assign below 3 variables as global variables where class start. 
4
5     SQLiteDatabase db; //Assign as a global variable
6     String DBName = "MyDB"; //Assign as a global variable
7     String TableName = "PeopleData"; //Assign as a global variable
8
9//Call 3 function inside oncreate method.
10
11protected void onCreate(Bundle savedInstanceState) {
12       super.onCreate(savedInstanceState);
13       setContentView(R.layout.activity_main);
14
15       createDB_Table(); //calling 3 functions.
16       InsertDataToDB();
17       ReadDBData();        
18            }
19
20public void createDB_Table(){ //This function use to create database, table & columns.
21             db = this.openOrCreateDatabase(DBName, MODE_PRIVATE, null);
22             db.execSQL("CREATE TABLE IF NOT EXISTS " + TableName + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, Name TEXT, Address TEXT, City TEXT, Country TEXT);");        
23             db.close();
24                            }
25
26public void InsertDataToDB(){ //This function use to inset values to database.
27           db = this.openOrCreateDatabase(DBName, MODE_PRIVATE, null);
28           ContentValues cv = new  ContentValues();       
29           cv.put("Name","Steve Hardy");
30           cv.put("Address","16 Somewhere Land");
31           cv.put("City","Colorado");
32           cv.put("Country","USA");
33           db.insert(TableName, null, cv);
34           db.close();
35                            }
36
37public void ReadDBData() { //This function use to read data from database.
38             db = this.openOrCreateDatabase(DBName, MODE_PRIVATE, null);
39             Cursor cursor = db.rawQuery("SELECT * FROM " + TableName, null);
40
41      if (cursor.getCount() > 0) { //check cursor is not empty.
42        cursor.moveToFirst();        
43        String DName = cursor.getString(cursor.getColumnIndex("Name"));
44        String DAddress = cursor.getString(cursor.getColumnIndex("Address"));
45        String DCity = cursor.getString(cursor.getColumnIndex("City"));
46        String DCountry = cursor.getString(cursor.getColumnIndex("Country"));  
47    //Got the values from database. Then you can set those values to text view or something you use.                            
48                                  }
49        cursor.close();
50        db.close();
51                            }
52        }