Android应用性能优化之使用SQLiteStatement优化SQLite操作

本文通过实验对比了SQLiteStatement的executeInsert方法与SQLiteDatabase的execSQL方法在批量插入数据时的性能差异。结果显示，在不使用事务的情况下，前者比后者快约5秒。

平常在做Android数据库操作时,都是用的execSQL之个方法. 今天偶然发现了SQLiteStatement这个类.让我想起了在做Java Web开发写JDBC的代码时Prestatement这个类.Prestatement不仅提高了效率,也解决了SQL注入的问题.那在Android中的SQLiteStatement,是否也会提高一些效率呢?

于是写了一个简单的测试,比较execSQL和SQLiteStatement的executeInsert方法插入1000条数据所需要的时间.都没有使用事物.

新建一个数据库和users表:

public class DBHelper extends SQLiteOpenHelper {

    private static final String DB_NAME = "userdb";
    private static final int DB_VERSION = 1;

    public DBHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        StringBuffer sql = new StringBuffer();
        sql.append("create table users");
        sql.append("(_id int PRIMARY KEY,name varchar,gender int,age int,phoneNumber varchar,address varchar)");

        db.execSQL(sql.toString());
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }

}

然后分别使用SQLiteDatabase 的execSQL方法和SQLiteStatement的executeInsert方法进入插入, 比较执行所需要的时间:

public class UserDao {

    private DBHelper dbHelper;
    private SQLiteDatabase db;

    private StringBuffer sql_insert;
    private List <User>  users;

    public UserDao(Context context){
        this.dbHelper = new DBHelper(context);
        this.db = dbHelper.getWritableDatabase();

        sql_insert = new StringBuffer();
        sql_insert.append("INSERT INTO users(name,gender,age,phoneNumber,address) ");
        sql_insert.append(" VALUES( ?, ?, ?, ?, ?)");

        users = new ArrayList <User> ();

        //测试数据
        for(int i = 0;i <1000;i++){
            User user = new User();
            user.setId(i);
            user.setName("name"+i);
            user.setGender(0);
            user.setAge(user.getRandomAge());
            user.setPhoneNumber("13800138000");
            user.setAddress("GuangDong ShenZhen No."+i);

            users.add(user);
        }

    }

    /**
     * 使用SQLiteDatabase 的execSQL方法插入数据 
     * @return 返回执行所需要的时间
     */
    public long insertexecSQL()
    {

        long start=System.currentTimeMillis();
        for(User user:users){
            Object[] bindArgs = {user.getName(),user.getGender(),user.getAge(),user.getPhoneNumber(),user.getAddress()};
            db.execSQL(sql_insert.toString(),bindArgs);
        }
        long end = System.currentTimeMillis();

        return end - start;
    }

    /**
     * 使用SQLiteStatement的executeInsert方法插入数据
     * @return 返回执行所需要的时间
     */
    public long insertStatement()
    {
        long start = System.currentTimeMillis();
        for(User user:users){
        SQLiteStatement statement=    db.compileStatement(sql_insert.toString());
        statement.bindString(1, user.getName());
        statement.bindLong(2, user.getGender());
        statement.bindLong(3, user.getAge());
        statement.bindString(4, user.getPhoneNumber());
        statement.bindString(5, user.getAddress());
        statement.executeInsert();
        }
        long end = System.currentTimeMillis();
        return end - start;
    }
}

界面方面就两个按钮,分别调用不同的插入方法, 并将执行所需的时间显示在Button上.

public class MainActivity extends Activity {

    private Button btn1;
    private Button btn2;

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

        final UserDao dao = new UserDao(this);

        btn1 = (Button) findViewById(R.id.btn1);
        btn2 = (Button) findViewById(R.id.btn2);

        btn1.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                btn1.setText(String.valueOf(dao.insertexecSQL()));
            }
        });

        btn2.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                btn2.setText(String.valueOf(dao.insertStatement()));
            }
        });

    }

}