通过代码代码示例对数据库进行CURD操作

代码分别使用两种方法进行数据的查找，具体示例如下；

     //数据库的基本操作

    private SQLiteDatabase db;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
		
		//通常继承SQLiteHelper
        MySQLiteOpenHelper mySQLiteOpenHelper = new MySQLiteOpenHelper(this,"student.db", null, 1);
        db = mySQLiteOpenHelper.getWritableDatabase();
    }

    public void btn_add(View view) {
        db.execSQL("insert into students ('name','age','money') values (?,?,?)",
                new String[] { "张三", "23", "230" });
        db.execSQL("insert into students ('name','age','money') values (?,?,?)",
                new String[] { "张四", "23", "230" });

        ContentValues values = new ContentValues();
        values.put("name", "李四");
        values.put("age", "123456");
        long i = db.insert("students", null, values);   // the row ID of the newly
                                                        // inserted row, or -1
                                                        // if an error occurred
        Toast.makeText(this, "add success" + i, Toast.LENGTH_SHORT).show();
    }

    public void btn_delete(View view) {
        // db.execSQL("delete from students where name = ?", new String[] { "张三"
        // });
        db.delete("students", "name like ?", new String[] { "张%" });
        Toast.makeText(this, "delete success", Toast.LENGTH_SHORT).show();
    }

    public void btn_update(View view) {
        Toast.makeText(this, "success", Toast.LENGTH_SHORT).show();
        // db.execSQL("update students set name = ?,age = ? where _id = ?",new
        // String[] { "张三", "100", "6" });
        ContentValues values = new ContentValues();
        values.put("name", "李四");
        values.put("age", "123");
        values.put("money", "46");
        db.update("students", values, "_id = ?", new String[] { "16" });
    }

    public void btn_query(View view) {
        Toast.makeText(this, "success", Toast.LENGTH_SHORT).show();
        Cursor cursor = db.query("students", new String[] { "name", "age" },
                "name like ?", new String[] { "张%" }, null, null, null, null);
        while (cursor.moveToNext()) {
            String name = cursor.getString(cursor.getColumnIndex("name"));
            int age = cursor.getInt(cursor.getColumnIndex("age"));
            Toast.makeText(this, name + " --- " + age, Toast.LENGTH_SHORT)
                    .show();
        }
    }

    public void btn_query2(View view) {
        Cursor cursor = db.rawQuery("select * from students where name like ?",
                new String[] { "张%" });
        while (cursor.moveToNext()) {
            String name = cursor.getString(cursor.getColumnIndex("name"));
            int age = cursor.getInt(cursor.getColumnIndex("age"));
            Toast.makeText(this, name + " --- " + age, Toast.LENGTH_SHORT)
                    .show();
        }
    }