SQLite数据库

SQLiteOpenHeleper
public class MySQLiteOpenHelper extends SQLiteOpenHelper {
    private static final String DB_NAME = "new.db";
    private static final int VERSION = 1;

    //创建库
    public MySQLiteOpenHelper(Context context) {
        super(context, DB_NAME, null, VERSION);
    }

    //创建表   第一次创建时调用，之后再不调用
    @Override
    public void onCreate(SQLiteDatabase db) {
        String sql = Constant.NewsTable.getCreateTableSQL();
        db.execSQL(sql);
    }
    //更新表
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("drop table " + Constant.NewsTable.TBL_NAME);
        onCreate(db);
    }
}

工具类，SQL语句
public class Constant {
    public static class NewsTable{
        public static final String TBL_NAME = "NEWS";
        public static final String TBL_COL_TITLE = "NEWSTITLE";
        public static final String TBL_COL_IMG = "NEWSIMG";
        public static final String TBL_COL_SRC = "NEWSSRC";
        public static final String TBL_COL_COMM = "NEWSCOMM";
        public static final String TBL_COL_DATE = "NEWSDATE";

        public static String getCreateTableSQL(){
            String sql = "CREATE TABLE IF NOT exists "
                    + TBL_NAME
                    + "("
                    + " _id integer primary key autoincrement ,"
                    + TBL_COL_TITLE + " text,"
                    + TBL_COL_IMG + " integer,"
                    + TBL_COL_SRC + " text,"
                    + TBL_COL_COMM + " text,"
                    + TBL_COL_DATE + " varchar(50)"
                    + ")";
            return sql;
        }
    }
}

增删改查
public void insertdata(){
    //调用帮助类的构造函数，去创建数据库
    MySQLiteOpenHelper mySQLiteOpenHelper = new MySQLiteOpenHelper(this);
    //调用帮助类的onCreate方法，去创建表
    SQLiteDatabase sqLiteDatabase = mySQLiteOpenHelper.getWritableDatabase();
    //准备要保存的数据
    ContentValues contentValues = new ContentValues();
    contentValues.put(Constant.NewsTable.TBL_COL_TITLE,text1.getText().toString());
    contentValues.put(Constant.NewsTable.TBL_COL_IMG,text2.getText().toString());
    contentValues.put(Constant.NewsTable.TBL_COL_SRC,text3.getText().toString());
    contentValues.put(Constant.NewsTable.TBL_COL_COMM,text4.getText().toString());
    contentValues.put(Constant.NewsTable.TBL_COL_DATE,text5.getText().toString());
    //调用insert方法，去保存数据
    sqLiteDatabase.insert(Constant.NewsTable.TBL_NAME,null,contentValues);
    //关闭sqLiteDatabase数据库
    sqLiteDatabase.close();
    Toast.makeText(getApplication(),"保存数据成功",Toast.LENGTH_SHORT).show();
    /*listView = (ListView) findViewById(R.id.SQLite);
    list = new ArrayList<Map<String,String>>();
    Map<String,String> map1 = new HashMap<String, String>();
    map1.put("title",text1.getText().toString());
    map1.put("img",text2.getText().toString());
    map1.put("src",text3.getText().toString());
    map1.put("comm",text4.getText().toString());
    map1.put("date",text5.getText().toString());
    list.add(map1);*/
}
    public void querydata(){
        MySQLiteOpenHelper mySQLiteOpenHelper = new MySQLiteOpenHelper(this);
        SQLiteDatabase sqLiteDatabase = mySQLiteOpenHelper.getReadableDatabase();
        Cursor cursor = sqLiteDatabase.query(
                Constant.NewsTable.TBL_NAME,
                new String[]{Constant.NewsTable.TBL_COL_TITLE,Constant.NewsTable.TBL_COL_DATE},
                null,null,null,null,null);
        while (cursor.moveToNext()){
            int titleIndex = cursor.getColumnIndex(Constant.NewsTable.TBL_COL_TITLE);
            String title = cursor.getString(titleIndex);
            int dateIndex = cursor.getColumnIndex(Constant.NewsTable.TBL_COL_DATE);
            String date = cursor.getString(dateIndex);
            Toast.makeText(getApplication(),title+date,Toast.LENGTH_SHORT).show();
            text1.setText(title);
            text5.setText(date);
        }
        cursor.close();
        sqLiteDatabase.close();
        Toast.makeText(getApplication(),"查询成功!!!",Toast.LENGTH_SHORT).show();
    }
    public void deletedata(){
        MySQLiteOpenHelper mySQLiteOpenHelper = new MySQLiteOpenHelper(this);
        SQLiteDatabase sqLiteDatabase = mySQLiteOpenHelper.getWritableDatabase();
        sqLiteDatabase.delete(
                Constant.NewsTable.TBL_NAME,
                Constant.NewsTable.TBL_COL_TITLE+" = ? ",
                new String[]{text1.getText().toString()}
        );
        sqLiteDatabase.close();
        Toast.makeText(getApplication(),"删除成功!!",Toast.LENGTH_SHORT).show();

    }
    public void updatedata(){
        MySQLiteOpenHelper mySQLiteOpenHelper = new MySQLiteOpenHelper(this);
        SQLiteDatabase sqLiteDatabase = mySQLiteOpenHelper.getWritableDatabase();
        String title = text1.getText().toString();
        ContentValues contentValues = new ContentValues();
        contentValues.put(Constant.NewsTable.TBL_COL_TITLE,title);
        sqLiteDatabase.update(
                Constant.NewsTable.TBL_NAME,
                contentValues,
                Constant.NewsTable.TBL_COL_TITLE+" = ? ",
                new String[]{text1.getText().toString()}
        );
        text1.setText(title);
        sqLiteDatabase.close();
        Toast.makeText(getApplication(),"更改完成！！",Toast.LENGTH_SHORT).show();
    }