Android SQLite总结(一)

前言

对于Android平台来说，系统内置了丰富的API来供开发人员操作SQLite，我们可以轻松的完成对数据的存取。下面就向大家介绍一下SQLite常用的操作方法。本篇文章主要用到SQLiteDatabase的一些函数。废话少说，直接贴代码！由于数据库中操作的对象时Student类，因此我们看一下Student.java代码：

[java]
package com.example.njupt.zhb.sqlite1;
import java.lang.String;
public class Student {
    int _id;//与所建立的表对应
    String name;
    int age;
    int grade;
    String info;
    public Student(String name,int age,int grade,String info){
        this.name=name;
        this.age=age;
        this.grade=grade;
        this.info=info;
    }
    public Student(){

    }
}

从Student类的定义可以看出，它有5个成员变量，其中第一个成员变量是其‘主键’，这个名称与数据库中表的主键要完全一致。

下面我们看一下MainActivity.java代码：

[java]
package com.example.njupt.zhb.sqlite1;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.util.Log;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.view.View;
import android.view.View.OnClickListener;
public class MainActivity extends Activity implements OnClickListener{
    public static final String DB_NAME="studentdata.db";
    Button insertBtn;
    Button updataGBtn;
    Button updataABtn;
    Button deleteBtn;
    Button selectBtn;
    Button displayBtn;
    Button closeBtn;
    ListView mListView;
    SQLiteDatabase db;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mListView=new ListView(this);
        BtnInit();
        OpenCreateDB();
    }
    public void OpenCreateDB(){
        db = openOrCreateDatabase(DB_NAME, this.MODE_PRIVATE, null);
        db.execSQL("DROP TABLE IF EXISTS students");
        db.execSQL("CREATE TABLE IF NOT EXISTS students (_id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR, age INTEGER,grade INTEGER, info VARCHAR)");
    }
    //插入数据到students表
    public void InsertData(){
        Student liSi =new Student("李四", 22, 87, "南京邮电大学通信工程");
        Student liHua = new Student("李华", 23, 78, "南京邮电大学软件工程");
        db.execSQL("INSERT INTO students VALUES (NULL,?,?,?,?)", new Object[]{"张三",21,98,"南京邮电大学电子信息工程"});
        db.execSQL("INSERT INTO students VALUES (NULL,?,?,?,?)", new Object[]{liSi.name,liSi.age,liSi.grade,liSi.info});
        db.execSQL("INSERT INTO students VALUES (NULL,'王五',19,99,'南京邮电大学网络工程')");
        ContentValues cvOfLiHua = new ContentValues();
        cvOfLiHua.put("name", liHua.name);
        cvOfLiHua.put("age", liHua.age);
        cvOfLiHua.put("grade", liHua.grade);
        cvOfLiHua.put("info", liHua.info);
        db.insert("students", null, cvOfLiHua);
        Log.d("msg","插入结束");
        Toast.makeText(this, "插入数据完成！", Toast.LENGTH_SHORT).show();
    }
    public void UpdateGrade(){
        ContentValues cv = new ContentValues();
        cv.put("grade", 85);
        //更新数据,将李四的成绩改为85分
        db.update("students", cv, "name = ?", new String[]{"李四"});
        Log.d("msg","李四的成绩已更新");
        Toast.makeText(this, "李四的成绩已更新", Toast.LENGTH_SHORT).show();
    }
    public void UpdateAge(){
        String sqlString="UPDATE students SET age=18 WHERE grade= 78";
        db.execSQL(sqlString);
        Log.d("msg","李华的年龄已更新");
        Toast.makeText(this, "李华的年龄已更新", Toast.LENGTH_SHORT).show();
    }
    public void Delete(){
        db.execSQL("DELETE FROM students WHERE name='张三'");
        Log.d("msg","张三的信息已经被删除");
        Toast.makeText(this, "张三的信息已经被删除", Toast.LENGTH_SHORT).show();
    }
    public void Select(){
        List<String> list=new ArrayList<String>();
        Cursor c = db.rawQuery("SELECT * FROM students WHERE grade >= ?", new String[]{"86"});
        Log.d("msg","--------------大于86分的同学----------------------------");
        while (c.moveToNext()) {
&n

补充：移动开发 , Android ,