android對sqlite數據庫操作(創建 增 刪 改 查)

android對sqlite數據庫操作(創建 增 刪 改 查)

 

操作sqlite數據庫第一種方法execSql()  rawQuery () 第二種方法:insert() delete() update()  query()

/**
 * 通過繼承SqliteOpenHelper來創建一個數據庫
 * @author Administrator
 *
 */
public class DbOpenhelper extends SQLiteOpenHelper
{
    private static String DATABASENAME = "secn.db";
    private static int DATABASEVERSION = 2;


    /**
     * (Context context, String name, CursorFactory factory,int version)
     * @param context 上下文對象
     * @param name 數據庫名稱 secb.db
     * @param factory  遊標工廠
     * @param version 數據庫版本
     */
    public DbOpenhelper(Context context)
    {
        super(context, DATABASENAME, null, DATABASEVERSION);
    }

    /**數據庫第一次被使用時創建數據庫
     * @param db 操作數據庫的
     */
    public void onCreate(SQLiteDatabase db)
    {
        //執行有更新行爲的sql語句
        db.execSQL("CREATE Table person (personid integer primary key autoincrement, name varchar(20), amount integer,age integer)");
    }

    /**數據庫版本發生改變時纔會被調用,數據庫在升級時纔會被調用;
     * @param db 操作數據庫
     * @param oldVersion 舊版本
     * @param newVersion 新版本
     */
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
    {
        db.execSQL("drop table if exists person");
        onCreate(db);
    }

}

  

/**
 * 對Person對象的sql操作(增刪改查)
 *
 * @author Administrator
 *
 */
public class PersonService
{

    private DbOpenhelper dbOpenHelper;

    public PersonService(Context context)
    {
        dbOpenHelper = new DbOpenhelper(context);
    }

    /**
     * 添加Person
     *
     * @param person
     */
    public void addPerson(Person person)
    {
        // 對讀和寫操作的方法
        // 如果當我們二次調用這個數據庫方法,他們調用的是同一個數據庫對象,在這裏的方法創建的數據調用對象是用的同一個對象
        SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
        db.execSQL("insert into Person(name,amount) values(?,?)", new Object[]
        { person.getName(), person.getAmount() });
    }

    /**
     * 修改Person
     *
     * @param person
     */
    public void modifyPerson(Person person)
    {
        SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
        db.execSQL("update Person set name=? where personid=?", new Object[]
        { person.getName(), person.getId() });
    }

    /**
     * 刪除Person
     *
     * @param person
     */
    public void deletePerson(Integer id)
    {
        SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
        db.execSQL("delete from Person where personid=?", new Object[]
        { id.toString() });
    }

    /**
     * 根據person的Id查詢Person對象
     *
     * @param id
     *            Person的ID
     * @return Person
     */
    public Person findPerson(Integer id)
    {
        // 只對讀的操作的方法
        SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
        // Cursor遊標的位置,默認是0,所有在操作時一定要先cursor.moveToFirst()一下,定位到第一條記錄
        // Cursor cursor =
        // db.rawQuery("select * from person Where personid=?",new
        // String[]{id.toString()});
        Cursor cursor = db.query("Person", new String[]
        { "personid", "name", "amount" }, "personid=?", new String[]
        { id.toString() }, null, null, null);
        if (cursor.moveToFirst())
        {
            int personId = cursor.getInt(cursor.getColumnIndex("personid"));
            String name = cursor.getString(cursor.getColumnIndex("name"));
            int amount = cursor.getInt(cursor.getColumnIndex("amount"));
            return new Person(personId, name, amount);
        }
        return null;
    }

    /**
     * 返回Person對象的集合
     *
     * @return List<Person>
     */
    public List<Person> findPersonList(Integer start, Integer length)
    {
        List<Person> persons = new ArrayList<Person>();
        // 只對讀的操作的方法
        SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
        Cursor cursor = db.rawQuery("select * from Person limit ?,?",
                new String[]
                { start.toString(), length.toString() });
        cursor = db.query("Person", null, null, null, null, null, null, start
                + "," + length);
        while (cursor.moveToNext())
        {
            int personId = cursor.getInt(cursor.getColumnIndex("personid"));
            String name = cursor.getString(cursor.getColumnIndex("name"));
            int amount = cursor.getInt(cursor.getColumnIndex("amount"));
            persons.add(new Person(personId, name, amount));
        }
        return persons;
    }

    /**
     * 返回Person的記錄總個數
     *
     * @return
     */
    public Long getCount()
    {
        SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
        Cursor cursor = db.rawQuery("select count(0) from Person ", null);
        // 這裏必定有一條記錄.所有不用判斷,直接移到第一條.
        cursor.moveToFirst();
        // 這裏只有一個字段時候 返回
        return cursor.getLong(0);
    }

    /**
     * 操作一個事務
     *
     * @return
     */
    public String getTransaction()
    {
        SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
        String success = "";
        db.beginTransaction();
        try
        {
            db.execSQL("update person set amount = amount+10 where personId=?",
                    new Object[]
                    { 1 });
            db.execSQL("update person set amount = amount-10 where personId=?",
                    new Object[]
                    { 2 });
            success = "success";
        } catch (Exception e)
        {
            success = "input";
        } finally
        {
            // db.setTransactionSuccessful();//設置事務標誌爲成功,當結束事務時就會提交事務
            db.endTransaction();
        }
        return success;
    }
}

public class SqliteTest extends AndroidTestCase
{
    /**
     * 創建數據庫及新建表
     */
    public void testCreateSqllite()
    {
        DbOpenhelper db = new DbOpenhelper(this.getContext());
        // 第一次調用該方法會調用數據庫
        db.getWritableDatabase();
    }

    /**
     * 添加Person
     */
    public void testSavePerson()
    {
        PersonService db = new PersonService(this.getContext());
        Person person = new Person();
        person.setName("LiMing");
        person.setAmount(888);
        db.addPerson(person);

    }

    /**
     * 更新Person
     */
    public void testUpdatePerson()
    {
        PersonService db = new PersonService(this.getContext());
        Person person = new Person();
        person.setId(1);
        person.setName("LiMingRen");
        person.setAmount(101);
        db.modifyPerson(person);

    }

    /**
     * 刪除Person
     */
    public void testDeletePerson()
    {
        PersonService db = new PersonService(this.getContext());
        db.deletePerson(1);

    }

    /**
     * 查詢一條Person記錄
     */
    public void testPerson()
    {
        PersonService db = new PersonService(this.getContext());
        Person person = db.findPerson(2);
        Log.i("SqliteTest", person.toString());

    }

    /**
     * 查詢Person集合對象
     */
    public void testPersonList()
    {
        PersonService db = new PersonService(this.getContext());
        List<Person> persons = db.findPersonList(0, 5);
        for (Person parson : persons)
        {
            Log.i("SqliteTest", parson.toString());
        }

    }
    /**
     * 測試一個事務
     */
    public void testgetTransaction(){
        PersonService db = new PersonService(this.getContext());
        String str = db.getTransaction();
        Log.i("SqliteTest", str);
    }
}

 

 

public class Person
{
    private int id;
    private String name;
    private int amount;

    public Person()
    {
    }

    public Person(int id, String name, int amount)
    {
        super();
        this.id = id;
        this.name = name;
        this.amount = amount;
    }

    public int getId()
    {
        return id;
    }

    public void setId(int id)
    {
        this.id = id;
    }

    public String getName()
    {
        return name;
    }

    public void setName(String name)
    {
        this.name = name;
    }

    public int getAmount()
    {
        return amount;
    }

    public void setAmount(int amount)
    {
        this.amount = amount;
    }

    public String toString()
    {
        return "ID:"+id+" Name:" + name + " Amount:" + amount;
    }
}