Android教程之SQlit数据库操作  (2)

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

   1.首先得新建数据库的代理类，通过这个类得到具体数据库的代理类。
mOpenHelper = new DatabaseHelper(this);
这个DatabaseHelper是继承SQLiteOpenHelper
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
2.由于操作的是SQLiteDatabase数据，故得到一个SQLiteDatabase类，这个类里边的方法可以对数据库进行具体的操作。

建立数据库：
mOpenHelper = new DatabaseHelper(v.getContext());
        SQLiteDatabase db = mOpenHelper.getWritableDatabase();
        String sql = "create table Student(" + "stud_no text not null, "
        + "stud_name text );";
        try {
        db.execSQL(sql);
        setTitle("create table ok!");
        } catch (SQLException e) {
        Log.e("ERROR", e.toString());
        setTitle("create table Error!");
        }

drop数据库：

        mOpenHelper = new DatabaseHelper(v.getContext());
        SQLiteDatabase db = mOpenHelper.getWritableDatabase();
        String sql = "drop table Student";
        try {
        db.execSQL(sql);
        setTitle("drop table ok!");
        } catch (SQLException e) {
        Log.e("ERROR", e.toString());
        setTitle("drop table Error!");
        }

插入语句：
    采用sql语句进行插入：

        mOpenHelper = new DatabaseHelper(v.getContext());
        SQLiteDatabase db = mOpenHelper.getWritableDatabase();
        String sql_1 = "insert into Student (stud_no, stud_name) values('S108', 'Lily Chen');";
        String sql_2 = "insert into Student (stud_no, stud_name) values('S201', 'Tom Kao');";
        String sql_3 = "insert into Student (stud_no, stud_name) values('S333', 'Peter Rabbit');";
        try {
        db.execSQL(sql_1);
        db.execSQL(sql_2);