안드로이드 게시판 공지사항 DB연동이 안되서요

Question

package io.github.hidroh.calendar;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;

import io.github.hidroh.calendar.BoardWriteActivity;

public class BoardListActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_board_list);
    }

    public void onWrite(View v) {
        Intent intent = new Intent(this, BoardWriteActivity.class);
        startActivity(intent);
    }
}

package io.github.hidroh.calendar;

public class BoardMainActivity {
    private String _id;
    private String title;
    private String password;
    private String content;
    private String hit;
    private String wdate;

    public String get_id() {
        return _id;
    }

    public void set_id(String _pw) {
        this._id = _pw;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }

    public String getHit() {
        return hit;
    }

    public void setHit(String hit) {
        this.hit = hit;
    }

    public String getWdate() {
        return wdate;
    }

    public void setWdate(String wdate) {
        this.wdate = wdate;
    }
}

package io.github.hidroh.calendar;

import android.content.Context;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class BoardWriteActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_board_write);
        findViewById(R.id.activity_board_write).setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                EditText etTitle = (EditText) findViewById(R.id.et_title_board);
                EditText etPassword = (EditText) findViewById(R.id.et_password_board);
                EditText etText = (EditText) findViewById(R.id.et_text_board);

                String stretTitle = etTitle.getText().toString();
                String stretPassword = etPassword.getText().toString();
                String stretText = etText.getText().toString();

                SQLiteDatabase db = openOrCreateDatabase("board.db", MODE_PRIVATE, null);
                String sql = "insert into board(\n" +
                        "title, password, text, content, hit, wdate)\n" +
                        " values('" + stretTitle + "','" + stretPassword + "','" + stretText + "','" + "',0,datetime('now','localtime'))";
                db.execSQL(sql);

                Intent intent = new Intent();
                setResult(RESULT_OK, intent);
                finish();
            }
        });
    };
}