android对sqlite数据库操作(创建 增 删 改 查)

android对sqlite数据库操作(创建 增 删 改 查)

 

操作sqlite数据库第一种方法execSql()  rawQuery () 第二种方法:insert() delete() update()  query()

 /**
  * 通过继承SqliteOpenHelper来创建一个数据库
  * @author Administrator
  *
  */
 public class DbOpenhelper extends SQLiteOpenHelper
 {
     private static String DATABASENAME = "secn.db";
     private static int DATABASEVERSION = 2;


     /**
      * (Context context, String name, CursorFactory factory,int version)
      * @param context 上下文对象
      * @param name 数据库名称 secb.db
      * @param factory  游标工厂
      * @param version 数据库版本
      */
     public DbOpenhelper(Context context)
     {
         super(context, DATABASENAME, null, DATABASEVERSION);
     }

     /**数据库第一次被使用时创建数据库
      * @param db 操作数据库的
      */
     public void onCreate(SQLiteDatabase db)
     {
         //执行有更新行为的sql语句
         db.execSQL("CREATE Table person (personid integer primary key autoincrement, name varchar(20), amount integer,age integer)");
     }

     /**数据库版本发生改变时才会被调用,数据库在升级时才会被调用;
      * @param db 操作数据库
      * @param oldVersion 旧版本
      * @param newVersion 新版本
      */
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
     {
         db.execSQL("drop table if exists person");
         onCreate(db);
     }

 }

  

 /**
  * 对Person对象的sql操作(增删改查)
  *
  * @author Administrator
  *
  */
 public class PersonService
 {

     private DbOpenhelper dbOpenHelper;

     public PersonService(Context context)
     {
         dbOpenHelper = new DbOpenhelper(context);
     }

     /**
      * 添加Person
      *
      * @param person
      */
     public void addPerson(Person person)
     {
         // 对读和写操作的方法
         // 如果当我们二次调用这个数据库方法,他们调用的是同一个数据库对象,在这里的方法创建的数据调用对象是用的同一个对象
         SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
         db.execSQL("insert into Person(name,amount) values(?,?)", new Object[]
         { person.getName(), person.getAmount() });
     }

     /**
      * 修改Person
      *
      * @param person
      */
     public void modifyPerson(Person person)
     {
         SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
         db.execSQL("update Person set name=? where personid=?", new Object[]
         { person.getName(), person.getId() });
     }

     /**
      * 删除Person
      *
      * @param person
      */
     public void deletePerson(Integer id)
     {
         SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
         db.execSQL("delete from Person where personid=?", new Object[]
         { id.toString() });
     }

     /**
      * 根据person的Id查询Person对象
      *
      * @param id
      *            Person的ID
      * @return Person
      */
     public Person findPerson(Integer id)
     {
         // 只对读的操作的方法
         SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
         // Cursor游标的位置,默认是0,所有在操作时一定要先cursor.moveToFirst()一下,定位到第一条记录
         // Cursor cursor =
         // db.rawQuery("select * from person Where personid=?",new
         // String[]{id.toString()});
         Cursor cursor = db.query("Person", new String[]
         { "personid", "name", "amount" }, "personid=?", new String[]
         { id.toString() }, null, null, null);
         if (cursor.moveToFirst())
         {
             int personId = cursor.getInt(cursor.getColumnIndex("personid"));
             String name = cursor.getString(cursor.getColumnIndex("name"));
             int amount = cursor.getInt(cursor.getColumnIndex("amount"));
             return new Person(personId, name, amount);
         }
         return null;
     }

     /**
      * 返回Person对象的集合
      *
      * @return List<Person>
      */
     public List<Person> findPersonList(Integer start, Integer length)
     {
         List<Person> persons = new ArrayList<Person>();
         // 只对读的操作的方法
         SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
         Cursor cursor = db.rawQuery("select * from Person limit ?,?",
                 new String[]
                 { start.toString(), length.toString() });
         cursor = db.query("Person", null, null, null, null, null, null, start
                 + "," + length);
         while (cursor.moveToNext())
         {
             int personId = cursor.getInt(cursor.getColumnIndex("personid"));
             String name = cursor.getString(cursor.getColumnIndex("name"));
             int amount = cursor.getInt(cursor.getColumnIndex("amount"));
             persons.add(new Person(personId, name, amount));
         }
         return persons;
     }

     /**
      * 返回Person的记录总个数
      *
      * @return
      */
     public Long getCount()
     {
         SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
         Cursor cursor = db.rawQuery("select count(0) from Person ", null);
         // 这里必定有一条记录.所有不用判断,直接移到第一条.
         cursor.moveToFirst();
         // 这里只有一个字段时候 返回
         return cursor.getLong(0);
     }

     /**
      * 操作一个事务
      *
      * @return
      */
     public String getTransaction()
     {
         SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
         String success = "";
         db.beginTransaction();
         try
         {
             db.execSQL("update person set amount = amount+10 where personId=?",
                     new Object[]
                     { 1 });
             db.execSQL("update person set amount = amount-10 where personId=?",
                     new Object[]
                     { 2 });
             success = "success";
         } catch (Exception e)
         {
             success = "input";
         } finally
         {
             // db.setTransactionSuccessful();//设置事务标志为成功,当结束事务时就会提交事务
             db.endTransaction();
         }
         return success;
     }
 }

 public class SqliteTest extends AndroidTestCase
 {
     /**
      * 创建数据库及新建表
      */
     public void testCreateSqllite()
     {
         DbOpenhelper db = new DbOpenhelper(this.getContext());
         // 第一次调用该方法会调用数据库
         db.getWritableDatabase();
     }

     /**
      * 添加Person
      */
     public void testSavePerson()
     {
         PersonService db = new PersonService(this.getContext());
         Person person = new Person();
         person.setName("LiMing");
         person.setAmount(888);
         db.addPerson(person);

     }

     /**
      * 更新Person
      */
     public void testUpdatePerson()
     {
         PersonService db = new PersonService(this.getContext());
         Person person = new Person();
         person.setId(1);
         person.setName("LiMingRen");
         person.setAmount(101);
         db.modifyPerson(person);

     }

     /**
      * 删除Person
      */
     public void testDeletePerson()
     {
         PersonService db = new PersonService(this.getContext());
         db.deletePerson(1);

     }

     /**
      * 查询一条Person记录
      */
     public void testPerson()
     {
         PersonService db = new PersonService(this.getContext());
         Person person = db.findPerson(2);
         Log.i("SqliteTest", person.toString());

     }

     /**
      * 查询Person集合对象
      */
     public void testPersonList()
     {
         PersonService db = new PersonService(this.getContext());
         List<Person> persons = db.findPersonList(0, 5);
         for (Person parson : persons)
         {
             Log.i("SqliteTest", parson.toString());
         }

     }
     /**
      * 测试一个事务
      */
     public void testgetTransaction(){
         PersonService db = new PersonService(this.getContext());
         String str = db.getTransaction();
         Log.i("SqliteTest", str);
     }
 }

 

 

 public class Person
 {
     private int id;
     private String name;
     private int amount;

     public Person()
     {
     }

     public Person(int id, String name, int amount)
     {
         super();
         this.id = id;
         this.name = name;
         this.amount = amount;
     }

     public int getId()
     {
         return id;
     }

     public void setId(int id)
     {
         this.id = id;
     }

     public String getName()
     {
         return name;
     }

     public void setName(String name)
     {
         this.name = name;
     }

     public int getAmount()
     {
         return amount;
     }

     public void setAmount(int amount)
     {
         this.amount = amount;
     }

     public String toString()
     {
         return "ID:"+id+" Name:" + name + " Amount:" + amount;
     }
 }