SQLiteStatement優化SQLite操做

時間 2019-11-08

標籤 sqlitestatement 優化 sqlite 欄目 Sqlite 简体版

原文原文鏈接

日常在作Android數據庫操做時,都是用的execSQL之個方法. 今天偶然發現了SQLiteStatement這個類.讓我想起了在作Java Web開發寫JDBC的代碼時Prestatement這個類.Prestatement不只提升了效率,也解決了SQL注入的問題.那在Android中的SQLiteStatement,是否也會提升一些效率呢?sql

因而寫了一個簡單的測試,比較execSQL和SQLiteStatement的executeInsert方法插入1000條數據所須要的時間.都沒有使用事物.數據庫

新建一個數據庫和users表:app

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) {
 
    }
 
}

而後分別使用SQLiteDatabase 的execSQL方法和SQLiteStatement的executeInsert方法進入插入, 比較執行所須要的時間:dom

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>();
 
        //測試數據
        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方法插入數據 
     * @return 返回執行所須要的時間
     */
    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方法插入數據
     * @return 返回執行所須要的時間
     */
    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;
    }
}

界面方面就兩個按鈕,分別調用不一樣的插入方法, 並將執行所需的時間顯示在Button上.異步

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()));
            }
        });
 
    }
 
}