Android小笔记数据库

//创建表

create table    person(_id  integer  primary key  autoincrement,name varchar(32),age  integer)

//插入数据

insert into person values(1,"bojie",18)

insert into person values(2,"pange",18)

//删除数据

delete from person where name="pange"

//查询数据

select  name  from person where _id=2

//修改数据

update person set name="pange+tanji"   where name="pange"

    sqlite

        public class MySqliteHelper extends SQLiteOpenHelper {

        /**

         * version  1

         * factory 数据查找的游标    默认null>>> cursor 

         * name  数据库名

         * @param context

         */

         public MySqliteHelper(Context context) {

         super(context, "my.db", null, 1);

         // TODO Auto-generated constructor stub

         }

         @Override

         public void onCreate(SQLiteDatabase db) {

         db.execSQL("create table person (_id  integer primary key  autoincrement,name varchar(32),age  integer)");

         }

     Dao层

public class PersonService {

private MySqliteHelper helper;

public PersonService(Context context) {

helper = new MySqliteHelper(context);

}

/**

 * 插入数据

 * @param p

 */

public void insert (Person p){

SQLiteDatabase db = helper.getWritableDatabase();

//db.execSQL("insert into person values("+p.getName()+","+p.getAge()+")");

if(db.isOpen()){

db.execSQL("insert  into person(name,age)values (?,?)", new Object[]{p.getName(),p.getAge()});

}

db.close();

}

/**

* 删除数据

* @param name

*/

public void del (String name){

SQLiteDatabase db = helper.getWritableDatabase();

if(db.isOpen()){

db.execSQL("delete from person where name=?", new  String[]{name});

}

db.close();

}

/**

* 修改数据

* @param oldName

* @param newName

*/

public void update (String oldName,String newName){

SQLiteDatabase db = helper.getWritableDatabase();

if(db.isOpen()){

db.execSQL("update person set  name=? where name=?", new  String[]{newName,oldName});

}

db.close();

}

/**

* 查询所有数据

* @return

*/

public List<Person> getAll(){

List<Person>  lists=new  ArrayList<Person>();

SQLiteDatabase db = helper.getReadableDatabase();

if(db.isOpen()){

Cursor cursor = db.rawQuery("select name ,age from person", null);

if(cursor!=null&&cursor.getCount()>0){

while(cursor.moveToNext()){

String name = cursor.getString(0);

int age = cursor.getInt(1);

Person person=new Person(name, age);

lists.add(person);

}

}

cursor.close();

return lists;

}

db.close();

return null;

}

/**

* 查询对应的数据

* @param id

* @return

*/

public Person getPersonById(int  id){

SQLiteDatabase db = helper.getReadableDatabase();

Person person=new Person();

if(db.isOpen()){

Cursor cursor = db.rawQuery("select name,age from person where _id=? ", new String[]{String.valueOf(id)});

if(cursor!=null&&cursor.getCount()>0){

if(cursor.moveToLast()){

String name = cursor.getString(0);

person.setName(name);

int age = cursor.getInt(1);

person.setAge(age);

}

}

cursor.close();

return person;

}

db.close();

return null;

}

本文出自 “Android小笔记” 博客，请务必保留此出处http://dreamwing.blog.51cto.com/9872128/1612138