package com.example.sql;import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;public class MySQLDatabase extends SQLiteOpenHelper {private static final String db_name = "myDatabse";//自定义的数据库名；private static final int version =1;//版本号public MySQLDatabase(Context context) {super(context, db_name, null, version);}
//该方法会自动调用，首先系统会检查该程序中是否存在数据库名为‘myDatabase’的数据库，如果存在则不会执行该方法，如果不存在则会执行该方法。
    @Overridepublic void onCreate(SQLiteDatabase arg0) {String  sql ="create table wx_user(" +"id int primary key," +"name varchar(30)," +"tou varchar(20)," +"content varchar(50)," +"dateTime varchar(30)" +")";arg0.execSQL(sql);}@Overridepublic void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {// TODO Auto-generated method stub
        }}

//实例化刚才上面我们创建的那个类
MySQLDatabase mySQLDatabase = new MySQLDatabase(MainActivity.this);
/*在通过getReadableDatabase()方法或者通过getWritableDatabase()
获得SQLDatabse类的对象；通过SQLDatabase类的对象来对数据进行操作；*/SQLiteDatabase sqlDatabase =  mySQLDatabase.getReadableDatabase();

//往数据库中插入数据的代码，在这里我使用的是execSQL(sql);
for(int i=0;i<20;i++){String sql = "insert into wx_user(id,name,tou,content,dateTime) values("+i+",'张校花"+i+"','aa','你今天会被打','11月19日')";sqlDatabase.execSQL(sql);}

package com.example.entiy;public class unserInFo {private int id;private String name;private String dateTime;private String tou;private String content;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getContent() {return content;}public void setContent(String content) {this.content = content;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getDateTime() {return datetime;}public void setDateTime(String dateTime) {this.dateTime= dateTime;}public String getTou() {return tou;}public void setTou(String tou) {this.tou = tou;}@Overridepublic String toString() {return "unserInFo [id="+id+,"name=" + name + ", dataTime=" + dataTime+ ", tou="+ tou+ "]";}public unserInFo() {super();// TODO Auto-generated constructor stub
    }}

//定义一个集合用来存放所有的结果
List<unserInFo> user = new ArrayList<unserInFo>();
//通过游标来获取表wx_user的信息，
Cursor c=sqlDatabase.query("wx_user", null, null, null, null, null, null);//先判断是否有第一条数据（ic.moveToFirst()将游标移到第一条数据，如果没有第一条数据则返回false,否则返回true）if(c.moveToFirst()){//通过getCount()来决定循环的次数getCount()是游标的总数量。for (int i = 0; i<c.getCount();i++) {unserInFo uif = new unserInFo();//将游标移动到下一条数据
            c.moveToNext();uif.setId(c.getInt(c.getColumnIndex("id")));uif.setLastdate(c.getString(c.getColumnIndex("dateTime")));uif.setName(c.getString(c.getColumnIndex("name")));uif.setZhao(c.getString(c.getColumnIndex("tou")));uif.setContent(c.getString(c.getColumnIndex("content")));user.add(uif);}
}    //最后数据库中获取到的数据就全部存放到user集合中了，我们只需要遍历user就能显示数据了。