sqlitedabase提供的CRUD（增、删、改、查）方法

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1.MySQLiteOpenHelper.Java

public class MySQLiteOpenHelper extends SQLiteOpenHelper {    private static String name = "hytc.db";    private static int version = 1;    public MySQLiteOpenHelper(Context context) {        super(context, name, null, version);        // TODO Auto-generated constructor stub    }    @Override    public void onCreate(SQLiteDatabase db) {        // TODO Auto-generated method stub        db.execSQL("CREATE TABLE IF NOT EXISTS user (_id integer primary key autoincrement, name varchar(20), phone varchar(11))");    }    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {        // TODO Auto-generated method stub    }}1
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2.DemoTest.java

public class DemoTest extends AndroidTestCase {    private MySQLiteOpenHelper helper;    public void testinsert() {        // 1.创建数据库管理对象        helper = new MySQLiteOpenHelper(getContext());        // 2.获取数据库对象        SQLiteDatabase db = helper.getWritableDatabase();        for (int i = 1; i < 40; i++) {            // 创建集合对象            ContentValues values = new ContentValues();            values.put("name", "chj" + i);            values.put("phone", "110" + i);            // 3.保存数据            long id = db.insert("user", "phone", values);            System.out.println(id);        }        db.close();    }    public void testupdate() {        // 1.创建数据库管理对象        helper = new MySQLiteOpenHelper(getContext());        // 2.获取数据库对象        SQLiteDatabase db = helper.getWritableDatabase();        // 创建集合对象        ContentValues values = new ContentValues();        values.put("name", "chjx");        values.put("phone", "110");        // 3.保存数据        long id = db.update("user", values, "_id=?", new String[] { 2 + "" });        System.out.println(id);        db.close();    }    public void testdelete() {        // 1.创建数据库管理对象        helper = new MySQLiteOpenHelper(getContext());        // 2.获取数据库对象        SQLiteDatabase db = helper.getWritableDatabase();        // 3.保存数据        long id = db.delete("user", "_id=?", new String[] { 2 + "" });        System.out.println(id);        db.close();    }    public void testquery() {        List<Map<String, Object>> data = new ArrayList<Map<String, Object>>();        // 1.创建数据库管理对象        helper = new MySQLiteOpenHelper(getContext());        // 2.获取数据库对象        SQLiteDatabase db = helper.getWritableDatabase();        // 3.查询数据        Cursor c = db.query("user", new String[] { "_id", "name", "phone" },                null, null, null, null, "_id desc", "1,2");        // 4.循环遍历        while (c.moveToNext()) {            Map<String, Object> map = new HashMap<String, Object>();            map.put("_id", c.getInt(c.getColumnIndex("_id")));            map.put("name", c.getString(c.getColumnIndex("name")));            map.put("phone", c.getString(c.getColumnIndex("phone")));            data.add(map);        }        c.close();        db.close();        for (Map p : data) {            System.out.println(p.get("name"));        }    }}

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