1. 首先我先创建一个包（package）entity

    1 package com.example.sqlgameplayer.entity; 2  3 /** 4  * Created by 徐伟杰 on 2016/9/25. 5  * 游戏玩家的实体类 6  */ 7  8 public class GamePlayer { 9     private int id;10     private String player;11     private int score;12     private int level;13     public GamePlayer(int id,String player,int score,int level){14         this.id=id;15         this.player=player;16         this.score=score;17         this.level=level;18     }19     public GamePlayer(String player,int score,int level){20         this.player=player;21         this.score=score;22         this.level=level;23     }24     public GamePlayer(){}25 26     public int getId() {27         return id;28     }29 30     public void setId(int id) {31         this.id = id;32     }33 34     public String getPlayer() {35         return player;36     }37 38     public void setPlayer(String player) {39         this.player = player;40     }41 42     public int getScore() {43         return score;44     }45 46     public void setScore(int score) {47         this.score = score;48     }49 50     public int getLevel() {51         return level;52     }53 54     public void setLevel(int level) {55         this.level = level;56     }57 58     @Override59     public String toString() {60         return "GamePlayer{" +61                 "id=" + id +62                 ", player=‘" + player + ‘\‘‘ +63                 ", score=" + score +64                 ", level=" + level +65                 ‘}‘;66     }67 }

    

2. 创建包db，在db里创建类GameMetaData

    1 package com.example.sqlgameplayer.db; 2  3 import android.provider.BaseColumns; 4  5 /** 6  * Created by 徐伟杰 on 2016/9/25. 7  * 数据库元数据 8  */ 9 10 public final class GameMetaData {11     private GameMetaData(){};12     public static abstract class GamePlayer implements BaseColumns{13         public static  final String TABLE_NAME="player_table";14         public static  final String PLAYER="player";15         public static final  String SCORE="score";16         public static  final String LEVEL="level";17     }18 }

    

3. 包db创建类DatabaseHelper

    1 package com.example.sqlgameplayer.db; 2  3 import android.content.Context; 4 import android.database.sqlite.SQLiteDatabase; 5 import android.database.sqlite.SQLiteOpenHelper; 6  7 /** 8  * Created by 徐伟杰 on 2016/9/25. 9  */10 11 public class DatabaseHelper extends SQLiteOpenHelper {12     private static final String DB_NAME="game.db";//数据库名字13     private static final int VERSION=1;//版本号14     private static final String CREATE_TABLE_PLAYER="CREATE TABLE IF NOT EXISTS player_table("+//如果没有表单创建表单player_table15             "_id INTEGER PRIMARY KEY AUTOINCREMENT,"+//id,主键自动增加16             "player TEXT,score INTEGER,level INTEGER)";//数据的类型17 18    private static final String DROP_TABLE_PLAYER="DROP TABLE IF EXISTS player_table";19     public DatabaseHelper(Context context) {20         //context,数据库名字，游标，版本号21         super(context, DB_NAME, null, VERSION);22     }23 24     @Override25     public void onCreate(SQLiteDatabase sqLiteDatabase) {26          sqLiteDatabase.execSQL(CREATE_TABLE_PLAYER);27     }28 //更新29     @Override30     public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {//i代表老版本，i1代表新版本31          sqLiteDatabase.execSQL(DROP_TABLE_PLAYER);32          sqLiteDatabase.execSQL(CREATE_TABLE_PLAYER);33         //先删除后创建34     }35 }

    

4. db包创建类DatabaseAdapter

     1 package com.example.sqlgameplayer.db;  2   3 import android.content.ContentValues;  4 import android.content.Context;  5 import android.database.Cursor;  6 import android.database.sqlite.SQLiteDatabase;  7   8   9 import com.example.sqlgameplayer.entity.GamePlayer; 10  11 import java.util.ArrayList; 12  13 /** 14  * Created by 徐伟杰 on 2016/9/25. 15  * 数据库的工具类 16  */ 17  18 public class DatabaseAdapter { 19     private DatabaseHelper dbHelper; 20     public DatabaseAdapter(Context context){dbHelper=new DatabaseHelper(context);} 21     //添加操作 22     public void add(GamePlayer gamePlayer){ 23         //获取可写的数据库 24         SQLiteDatabase db=dbHelper.getWritableDatabase(); 25         ContentValues values=new ContentValues(); 26         values.put(GameMetaData.GamePlayer.PLAYER,gamePlayer.getPlayer()); 27         values.put(GameMetaData.GamePlayer.SCORE,gamePlayer.getScore()); 28         values.put(GameMetaData.GamePlayer.LEVEL,gamePlayer.getLevel()); 29         db.insert(GameMetaData.GamePlayer.TABLE_NAME,null,values); 30         db.close(); 31     } 32     //删除操作(实际开发应用中是不会删除的，而是隐藏) 33     public void delete(int id){ 34      SQLiteDatabase db=dbHelper.getWritableDatabase(); 35         String whereClause=GameMetaData.GamePlayer._ID+"=?"; 36         String[] whereArgs={String.valueOf(id)}; 37         //表名，条件，条件的值 38         db.delete(GameMetaData.GamePlayer.TABLE_NAME,whereClause,whereArgs); 39         db.close(); 40     } 41     //更新操作 42     public void update(GamePlayer gamePlayer){ 43      SQLiteDatabase db=dbHelper.getWritableDatabase(); 44         ContentValues values=new ContentValues(); 45         values.put(GameMetaData.GamePlayer.PLAYER,gamePlayer.getPlayer()); 46         values.put(GameMetaData.GamePlayer.SCORE,gamePlayer.getScore()); 47         values.put(GameMetaData.GamePlayer.LEVEL,gamePlayer.getLevel()); 48         String whereClause=GameMetaData.GamePlayer._ID+"=?"; 49         String[] whereArgs={String.valueOf(gamePlayer.getId())}; 50         db.update(GameMetaData.GamePlayer.TABLE_NAME,values,whereClause,whereArgs); 51         db.close(); 52     } 53     //查询 54     public GamePlayer findById(int id) { 55         //获取只读 56         SQLiteDatabase db=dbHelper.getReadableDatabase(); 57         //属性:是否可重复，表名，读多少个列表(这里数据比较少所以填null)，条件，条件值，分组，排序等等 58         Cursor c=db.query(true, GameMetaData.GamePlayer.TABLE_NAME,null, GameMetaData.GamePlayer._ID+"=?",new String[]{String.valueOf(id)},null,null,null,null); 59         GamePlayer gamePlayer=null; 60         if(c.moveToNext()) { 61             gamePlayer=new GamePlayer(); 62             gamePlayer.setId(c.getInt(c.getColumnIndexOrThrow(GameMetaData.GamePlayer._ID))); 63             gamePlayer.setPlayer(c.getString(c.getColumnIndexOrThrow(GameMetaData.GamePlayer.PLAYER))); 64             gamePlayer.setScore(c.getInt(c.getColumnIndexOrThrow(GameMetaData.GamePlayer.SCORE))); 65             gamePlayer.setLevel(c.getInt(c.getColumnIndexOrThrow(GameMetaData.GamePlayer.LEVEL))); 66         } 67         c.close(); 68         db.close(); 69  70         return gamePlayer; 71     } 72     //查询所有 73     public ArrayList<GamePlayer> findAll(){ 74         SQLiteDatabase db=dbHelper.getReadableDatabase(); 75         //收集 _id,player,score,level(注意这里最好不要使用*号，回影响性能)从paly_table 排序通过score 降序 76         String sql="select _id,player,score,level from player_table order by score desc"; 77         Cursor c=db.rawQuery(sql,null); 78         ArrayList<GamePlayer> gamePlayers=new ArrayList<>(); 79         GamePlayer gamePlayer=null; 80         while (c.moveToNext()){ 81             gamePlayer=new GamePlayer(); 82             gamePlayer.setId(c.getInt(c.getColumnIndexOrThrow(GameMetaData.GamePlayer._ID))); 83             gamePlayer.setPlayer(c.getString(c.getColumnIndexOrThrow(GameMetaData.GamePlayer.PLAYER))); 84             gamePlayer.setScore(c.getInt(c.getColumnIndexOrThrow(GameMetaData.GamePlayer.SCORE))); 85             gamePlayer.setLevel(c.getInt(c.getColumnIndexOrThrow(GameMetaData.GamePlayer.LEVEL))); 86             gamePlayers.add(gamePlayer); 87         } 88         c.close(); 89         db.close(); 90         return gamePlayers; 91     } 92     //获取总记录数 93     public int getCount(){ 94         int count=0; 95         String sql="select count(_id) from player_table"; 96         SQLiteDatabase db=dbHelper.getReadableDatabase(); 97         Cursor c=db.rawQuery(sql,null); 98         c.moveToFirst(); 99         count=c.getInt(0);100         c.close();101         db.close();102        return count;103     }104 }

    

关于Android SQLite数据库后台处理的小例子