Saving data to the sqlite database?

This is my main activity and I'm getting exception at 29th line of insertData() in MainActivity method and MyDatabaseAdapter() class contains the schema.Can u please help me with where I'm getting the error?

import android.content.ContentValues;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    EditText editText;
    Button button;

   MyDatabaseAdapter myDatabaseAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        editText=(EditText)findViewById(R.id.editText);
        button=(Button)findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String name=editText.getText().toString();
                long id=myDatabaseAdapter.insertData(name);
                if(id<0)
                {
                    Toast.makeText(MainActivity.this,"Unsuccessful",Toast.LENGTH_LONG);
                }
                else
                {
                    Toast.makeText(MainActivity.this,"Successfull",Toast.LENGTH_LONG).show();
                }

            }
        });
    }


}

This is my sqlite helper class

import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;



public class MyDatabaseAdapter  {

    MyDatabase myDatabase;
    MyDatabaseAdapter(Context context)
    {
        myDatabase=new MyDatabase(context);
    }
    public long insertData(String name)
    {
        SQLiteDatabase sqLiteDatabase=myDatabase.getWritableDatabase();
        ContentValues contentValues=new ContentValues();
        contentValues.put(MyDatabase.NAME,name);
        long id=sqLiteDatabase.insert(myDatabase.TABLE_NAME,null,contentValues);
        return id;
    }

   static class MyDatabase extends SQLiteOpenHelper
   {
       private static final String DATABASE_NAME="Mydatabase";
       private static final int DATABASE_VERSION=3;
       private static final String TABLE_NAME="MyContacts";
       private static final String NAME="Name";
       // private static final String ADDRESS="Address";
       private static final String UID="_id";
       private static final String CREATE_TABLE="CREATE TABLE "+TABLE_NAME+"("+UID+" INTEGER PRIMARY KEY AUTOINCREMENT,"+NAME+" VARCHAR(255),;";
       private static final String DROP_TABLE="DROP TABLE IF EXISTS" +TABLE_NAME;

       public MyDatabase(Context context) {
           super(context, DATABASE_NAME, null, DATABASE_VERSION);
           Toast.makeText(context,"Constructor is called",Toast.LENGTH_LONG).show();
       }

       @Override
       public void onCreate(SQLiteDatabase db) {
           db.execSQL(CREATE_TABLE);
       }

       @Override
       public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
           db.execSQL(DROP_TABLE);
           onCreate(db);
       }
   }
}