SQLiteとAndroid

UserOpenHelperでSQLiteOpenHelperを継承します。

package self.mydbapp;

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

/**
 * Created by narishige on 2016/11/21.
 */

public class UserOpenHelper extends SQLiteOpenHelper {

    public static final String DB_NAME = "myapp.db";
    public static final int DB_VERSION = 1;
    public static final String CREATE_TABLE =
            "create table " + UserContract.Users.TABLE_NAME + " (" +
                    UserContract.Users._ID + " integer primary key autoincrement," +
                    UserContract.Users.COL_NAME + "name text," +
                    UserContract.Users.COL_SCORE + "score integer)";
    public static final String INIT_TABLE =
            "insert into users (name, score) values " +
                    "('yoshimoto', 55), " +
                    "('kimura', 45), " +
                    "('igarashi', 82)";
    public static final String DROP_TABLE =
            "drop table if exists users";

    public UserOpenHelper(Context c){
        super(c, DB_NAME, null, DB_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
        // create table
        sqLiteDatabase.execSQL(CREATE_TABLE);
        // init table
        sqLiteDatabase.execSQL(INIT_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
        // drop table
        sqLiteDatabase.execSQL(DROP_TABLE);
        // onCreate
        onCreate(sqLiteDatabase);
    }
}

insert, delete, update

        UserOpenHelper userOpenHelper = new UserOpenHelper(this);
        SQLiteDatabase db = userOpenHelper.getWritableDatabase();
        // open db
        ContentValues newUser = new ContentValues();
        newUser.put(UserContract.Users.COL_NAME, "tanaka");
        newUser.put(UserContract.Users.COL_SCORE, "42");
        long newID = db.insert(
          UserContract.Users.TABLE_NAME,
                null,
                newUser
        );
        
        ContentValues newScore = new ContentValues();
        newScore.put(UserContract.Users.COL_SCORE, 100);
        int updatedCount = db.update(
                UserContract.Users.TABLE_NAME,
                newScore,
                UserContract.Users.COL_NAME + " = ?",
                new String[] {"sakai"}
        );
        int deletedCount = db.delete(
          UserContract.Users.TABLE_NAME,
                UserContract.Users.COL_NAME + " = ?",
                new String[] {"sakai"}
        );
        
        Cursor c = null;
        c = db.query(
                UserContract.Users.TABLE_NAME,
                null, // fields
                null, // where
                null, // where arg
                null, // groupby
                null,
                null
        );

トランザクション

 try {
            db.beginTransaction();
            db.execSQL("update users " +
                    "set score = score + 10 " +
                    "where name = 'kaneko'");
            db.execSQL("update users " +
                    "set score = score + 10 " +
                    "where name = 'muraoka'");
        } catch(SQLException e){
            e.printStackTrace();
        } finally {
            db.endTransaction();
        }