SQLiteDatabase

一、继承SQLiteOpenHelper 创建数据库

public class DBOpenHelper extends SQLiteOpenHelper {public DBOpenHelper(Context context) {super(context, "itcast.db", null, 3);// <包> /databases/}@Overridepublic void onCreate(SQLiteDatabase db) {// 数据库第一次创建时候调用的db.execSQL("CREATE TABLE person (personid integer primary key autoincrement,name varchar(20),phone varchar(20),amount integer)");}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVerson, int newVerson) {// 版本发生变化时候调用db.execSQL("ALTER TABLE person ADD amount varchar(20) NULL");}}

二、创建一个服务类，对数据库进行添删改查。

public class PersonService {private DBOpenHelper dbOpenHelper;public PersonService(Context context) {this.dbOpenHelper = new DBOpenHelper(context);}public void save(Person person){SQLiteDatabase db = dbOpenHelper.getWritableDatabase();db.execSQL("insert into person(name,phone,amount) values(?,?,?)", new Object[]{person.getName(),person.getPhone(),person.getAmount()});}

      //保存

public void save1(Person person){SQLiteDatabase db = dbOpenHelper.getWritableDatabase();ContentValues values = new ContentValues();values.put("name",person.getName());values.put("phone",person.getPhone());db.insert("person", null, values);}public void delete(Integer id){SQLiteDatabase db = dbOpenHelper.getWritableDatabase();db.execSQL("delete from person where personid=?", new Object[]{id});}public void update(Person person){SQLiteDatabase db = dbOpenHelper.getWritableDatabase();db.execSQL("update person set name=?, phone=? ,amount=? where personid =?",new Object[]{person.getName(),person.getPhone(),person.getAmount(),person.getId()});}//查找public Person find(Integer id){SQLiteDatabase db = dbOpenHelper.getWritableDatabase();      Cursor cursor = db.rawQuery("select * from person where personid=?", new String[]{id.toString()});if(cursor.moveToFirst()){int personid = cursor.getInt(cursor.getColumnIndex("personid"));String name = cursor.getString(cursor.getColumnIndex("name"));String phone = cursor.getString(cursor.getColumnIndex("phone"));int amount = cursor.getInt(cursor.getColumnIndex("amount"));return new Person(personid,name,phone,amount);}cursor.close();      return null;}/** * @param offset 跳过前面多少条记录 * @param maxResult 每页获取多少条记录 * @return */public List<Person> getScrollData (int offset,int maxResult){List<Person> persons = new ArrayList<Person>();SQLiteDatabase db = dbOpenHelper.getWritableDatabase();Cursor cursor = db.rawQuery("select * from person order by personid asc limit?,?", new String[]{String.valueOf(offset),String.valueOf(maxResult)});while(cursor.moveToNext()){int personid = cursor.getInt(cursor.getColumnIndex("personid"));String name = cursor.getString(cursor.getColumnIndex("name"));String phone = cursor.getString(cursor.getColumnIndex("phone"));int amount = cursor.getInt(cursor.getColumnIndex("amount"));persons.add(new Person(personid,name,phone,amount)); }cursor.close();    return persons;}/** *  修改为_id，才能使用简单适配器 * @param offset * @param maxResult * @return */public Cursor getCursorScrollData (int offset,int maxResult){SQLiteDatabase db = dbOpenHelper.getWritableDatabase();Cursor cursor = db.rawQuery("select personid as _id,name,phone,amount from person order by personid asc limit?,?", //只有成为_id才能使用简单适配器new String[]{String.valueOf(offset),String.valueOf(maxResult)});    return cursor;}public long getCount(){SQLiteDatabase db = dbOpenHelper.getWritableDatabase();Cursor cursor = db.rawQuery("select count(*) from person", null);cursor.moveToNext();long result = cursor.getLong(0);return result;}}

<span style="font-size:18px;">使用数据库自带的方法添删改查</span>

public class OtherPersonService {private DBOpenHelper dbOpenHelper;public OtherPersonService(Context context) {this.dbOpenHelper = new DBOpenHelper(context);}public void save(Person person) {//Log.e("save", "开始添加数据");SQLiteDatabase db = dbOpenHelper.getWritableDatabase();//Log.e("save", "操作数据库");//ContentValues values = new ContentValues();//values.put("name", person.getName());//values.put("phone", person.getPhone());//values.put("amount", person.getAmount());//db.insert("person", null, values); db.execSQL("insert into person(name,phone,amount)values(?,?,?)",new Object[]{person.getName(),person.getPhone(),person.getAmount()});}public void delete(Integer id) {SQLiteDatabase db = dbOpenHelper.getWritableDatabase();db.delete("person", "personid=?", new String[] { id.toString() });}public void payment() {SQLiteDatabase db = dbOpenHelper.getWritableDatabase();db.beginTransaction();// 开启事务try {db.execSQL("update person set amount = amount-10 where personid=1");db.execSQL("update person set amount = amount+10 where personid=1");db.setTransactionSuccessful();} finally {db.endTransaction();}}public void update(Person person) {SQLiteDatabase db = dbOpenHelper.getWritableDatabase();ContentValues values = new ContentValues();values.put("name", person.getName());values.put("phone", person.getPhone());values.put("amount", person.getAmount());db.update("person", values, "personid=?", new String[] { person.getId().toString() });}public Person find(Integer id) {SQLiteDatabase db = dbOpenHelper.getReadableDatabase();Cursor cursor = db.query("person", null, "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"));String phone = cursor.getString(cursor.getColumnIndex("phone"));int amount = cursor.getInt(cursor.getColumnIndex("amount"));return new Person(personid, name, phone, amount);}return null;}/** *  * @param offset *            跳过多少条记录 * @param maxResult *            湖区多少条记录 * @return */public List<Person> getScrollData(int offset, int maxResult) {Log.e("save", "进入分页");List<Person> persons = new ArrayList<Person>();SQLiteDatabase db = dbOpenHelper.getReadableDatabase();Cursor cursor = db.query("person", null, null, null, null, null,"personid asc", offset + "," + maxResult);while (cursor.moveToNext()) {int personid = cursor.getInt(0);String name = cursor.getString(1);String phone = cursor.getString(cursor.getColumnIndex("phone"));int amount = cursor.getInt(cursor.getColumnIndex("amount"));persons.add(new Person(personid, name, phone, amount));}cursor.close();return persons;}public List<Person> getScrollData2() {List<Person> persons = new ArrayList<Person>();SQLiteDatabase db = dbOpenHelper.getReadableDatabase();Cursor cursor = db.rawQuery("select * from person",null);while (cursor.moveToNext()) {int personid = cursor.getInt(cursor.getColumnIndex("personid"));String name = cursor.getString(cursor.getColumnIndex("name"));String phone = cursor.getString(cursor.getColumnIndex("phone"));int amount = cursor.getInt(cursor.getColumnIndex("amount"));persons.add(new Person(personid, name, phone, amount));}cursor.close();return persons;}public Cursor getCursorScrollData(int offset, int maxResult) {SQLiteDatabase db = dbOpenHelper.getReadableDatabase();Cursor cursor = db.rawQuery("select personid as _id,name, phone,amount from person order by personid",new String[] { String.valueOf(offset),String.valueOf(maxResult) });return cursor;}public long getConut() {SQLiteDatabase db = dbOpenHelper.getReadableDatabase();Cursor cursor = db.query("person", new String[] { "count(*)" }, null,null, null, null, null);cursor.moveToFirst();long result = cursor.getLong(0);return result;}}