public class sqlitedemo extends SQLiteOpenHelper {

    public sqlitedemo(Context context) {
//      String name, CursorFactory factory,
        
        super(context, "xiaoer", null, 1);
        // TODO Auto-generated constructor stub
    }
    
    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        db.execSQL("create table two(_id integer primary key autoincrement,name varchar(30),age varchar(10))");
        Log.i("sqlite","oncreate");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        Log.i("sqlite","onUpgrade");
    }

}

需要继承自SQLiteOpenHelper

super(context, "xiaoer", null, 1);

有4个参数第二个是数据库的名字 第三个是用来操作表的填null默认用系统自带的 1是数据库的版本

varchar： 是类型参数可以指定对应数的大小

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)

是再版本升级的时候会调用oncreate之会调用一次 可以进行数据库表的操作等
例如：增加一个字段

db.execSQL("alter table two add heights integer");

增删该查demo

public class sqliteStudent {

    private SQLiteDatabase db;

    public sqliteStudent(Context context, sqliteTableOpenHelper table) {
        super();

        db = table.getWritableDatabase();
        
        Log.e("haha", db.toString());

    }

    public void add(Student s) {
        db.execSQL("insert into student values(null,?,?)",
                new Object[] { s.getName(), s.getNumber() });
    }

    public void delete(Student s) {
        db.execSQL("delete from student where age=?",
                new Object[] { s.getNumber() });
    }

    public void update(Student s) {
        db.execSQL("update student set name=?", new Object[] { "haha" });
    }

    public Student query(Student s) {
        Cursor rawQuery = db.rawQuery("select *from student where age=?",
                new String[] { s.getNumber() + "" });
        while (rawQuery.moveToNext()) {

        }

        return new Student("xaioer", 20);
    }

}

demo::

package com.example.sqlitedemo3;

import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

public class studentSqlite {
    private sqliteManager sq;
    private SQLiteDatabase db;

    public studentSqlite(Context context) {

        super();

        sq = new sqliteManager(context);
        db = sq.getWritableDatabase();
    }

    public void add(Student s) {
        db.execSQL("insert into student values(null,?,?)",
                new Object[] { s.getName(), s.getAge() });
    }

    public void delete(Student s) {
        db.execSQL("delete from student where name=?",
                new Object[] { s.getName() });
    }

    public void update(Student s) {

        db.execSQL("update student set name=?", new Object[] { s.getName() });
    }

    public List<Student> query() {
        db = sq.getReadableDatabase();
        Cursor rawQuery = db.rawQuery("select *from student", null);
        List<Student> datas = new ArrayList<Student>();
        Student s = new Student();
        while (rawQuery.moveToNext()) {
            //得到每行对应字段的索引通过索引得到对应的内容
            s.setName(rawQuery.getString(rawQuery.getColumnIndex("name")));
            s.setAge(rawQuery.getString(rawQuery.getColumnIndex("age")));
            datas.add(s);
        }
              //记得关闭啊
        rawQuery.close();
        return datas;
    }

}





package com.example.sqlitedemo3;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;

public class sqliteManager extends SQLiteOpenHelper {

    public sqliteManager(Context context) {
        super(context, "students", null, 1);
        // TODO Auto-generated constructor stub
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        db.execSQL("create table student(_id integer primary key autoincrement,name varchar(30),age varchar(10))");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        
    }

}