Android数据存储SQLite使用实例(附源码)(转载)

Posted 2020-07-24

原文地址：http://blog.csdn.net/wirelessqa/article/details/8583101

java当中提供了相当多的封装好的类来执行对SqlLite的操作，如：

SQLiteDatabase 作为数据库操作的类，类似于C#当中我们自己写的helper，PS(java对此还真是高度封装)

SQLiteOpenHelper 作为作为维护和管理数据库的基类
实例: 会员信息管理

功能：1.查看数据库 2.清空数据库 3.增加会员 4.删除会员 5.更新会员 6.查找会员

DBHelper类继承自SQLiteOpenHelper

package com.wirelessqa.sqlite;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

/**
 * DBHelper继承了SQLiteOpenHelper，作为维护和管理数据库的基类
 * @author bixiaopeng 2013-2-16 下午3:05:52
 */
public class DBHelper  extends SQLiteOpenHelper{
    //final成员变量是常量 只能赋值一次
    public static final String DB_NAME = "wirelessqa.db";
    public static final String DB_TABLE_NAME = "info";
    private static final int DB_VERSION=1;
    public DBHelper(Context context) {
        //Context context, String name, CursorFactory factory, int version
        //factory输入null,使用默认值
        super(context, DB_NAME, null, DB_VERSION);
    }
    //数据第一次创建的时候会调用onCreate
    @Override
    public void onCreate(SQLiteDatabase db) {        
        //创建表
          db.execSQL("CREATE TABLE IF NOT EXISTS info" +  
                    "(_id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR, age INTEGER, website STRING,weibo STRING)");
          Log.i(WirelessQA.TAG, "create table");
    }
    //数据库第一次创建时onCreate方法会被调用，我们可以执行创建表的语句，
    //当系统发现版本变化之后，会调用onUpgrade方法，我们可以执行修改表结构等语句
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        //在表info中增加一列other
        //db.execSQL("ALTER TABLE info ADD COLUMN other STRING");  
        Log.i("WIRELESSQA", "update sqlite "+oldVersion+"---->"+newVersion);
    }
    

}

依靠DBHelper和SQLiteDatabase 实现对业务的操作：

package com.wirelessqa.sqlite;

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

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

/**
 *DBManager是建立在DBHelper之上，封装了常用的业务方法
 * @author bixiaopeng 2013-2-16 下午3:06:26
 */
public class DBManager {

    private DBHelper       helper;
    private SQLiteDatabase db;

    public DBManager(Context context){
        helper = new DBHelper(context);
        //从helper中获取database操作类 helper已经把数据库封装好了
        db = helper.getWritableDatabase();
    }

    /**
     * 向表info中增加多个成员信息
     * 
     * @param memberInfo
     */
    public void add(List<MemberInfo> memberInfo) {
        db.beginTransaction();// 开始事务
        try {
            for (MemberInfo info : memberInfo) {
                Log.i(WirelessQA.TAG, "------add memberInfo----------");
                Log.i(WirelessQA.TAG, info.name + "/" + info.age + "/" + info.website + "/" + info.weibo);
                // 向表info中插入数据
                db.execSQL("INSERT INTO info VALUES(null,?,?,?,?)", new Object[] { info.name, info.age, info.website,
                        info.weibo });
            }
            db.setTransactionSuccessful();// 事务成功
        } finally {
            db.endTransaction();// 结束事务
        }
    }

    /**向表info中增加一个成员信息
     * @param _id
     * @param name
     * @param age
     * @param website
     * @param weibo
     */
    public void add(int _id, String name, int age, String website, String weibo) {
        Log.i(WirelessQA.TAG, "------add data----------");
        ContentValues cv = new ContentValues();
        // cv.put("_id", _id);
        cv.put("name", name);
        cv.put("age", age);
        cv.put("website", website);
        cv.put("weibo", weibo);
        db.insert(DBHelper.DB_TABLE_NAME, null, cv);
        Log.i(WirelessQA.TAG, name + "/" + age + "/" + website + "/" + weibo);
    }

    /**
     * 通过name来删除数据
     * 
     * @param name
     */
    public void delData(String name) {
        // ExecSQL("DELETE FROM info WHERE name ="+"‘"+name+"‘");
        String[] args = { name };
        db.delete(DBHelper.DB_TABLE_NAME, "name=?", args);
        Log.i(WirelessQA.TAG, "delete data by " + name);

    }

    /**
     * 清空数据
     */
    public void clearData() {
        ExecSQL("DELETE FROM info");
        Log.i(WirelessQA.TAG, "clear data");
    }

    /**
     * 通过名字查询信息,返回所有的数据
     * 
     * @param name
     */
    public ArrayList<MemberInfo> searchData(final String name) {
        String sql = "SELECT * FROM info WHERE name =" + "‘" + name + "‘";
        return ExecSQLForMemberInfo(sql);
    }

    public ArrayList<MemberInfo> searchAllData() {
        String sql = "SELECT * FROM info";
        return ExecSQLForMemberInfo(sql);
    }

    /**
     * 通过名字来修改值
     * 
     * @param raw
     * @param rawValue
     * @param whereName
     */
    public void updateData(String raw, String rawValue, String whereName) {
        String sql = "UPDATE info SET " + raw + " =" + " " + "‘" + rawValue + "‘" + " WHERE name =" + "‘" + whereName
                     + "‘";
        ExecSQL(sql);
        Log.i(WirelessQA.TAG, sql);
    }

    /**
     * 执行SQL命令返回list
     * 
     * @param sql
     * @return
     */
    private ArrayList<MemberInfo> ExecSQLForMemberInfo(String sql) {
        ArrayList<MemberInfo> list = new ArrayList<MemberInfo>();
        Cursor c = ExecSQLForCursor(sql);
        while (c.moveToNext()) {
            MemberInfo info = new MemberInfo();
            info._id = c.getInt(c.getColumnIndex("_id"));
            info.name = c.getString(c.getColumnIndex("name"));
            info.age = c.getInt(c.getColumnIndex("age"));
            info.website = c.getString(c.getColumnIndex("website"));
            info.weibo = c.getString(c.getColumnIndex("weibo"));
            list.add(info);
        }
        c.close();
        return list;
    }

    /**
     * 执行一个SQL语句 不返回任何数据
     * 
     * @param sql
     */
    private void ExecSQL(String sql) {
        try {
            db.execSQL(sql);
            Log.i("execSql: ", sql);
        } catch (Exception e) {
            Log.e("ExecSQL Exception", e.getMessage());
            e.printStackTrace();
        }
    }

    /**
     * 执行SQL，返回一个游标
     * 
     * @param sql
     * @return
     */
    private Cursor ExecSQLForCursor(String sql) {
        Cursor c = db.rawQuery(sql, null);
        return c;
    }

    public void closeDB() {
        db.close();
    }

}

会员信息的JavaBean – MemberInfo.java

首页显示 – MainActivity.java

显示结果页 – DisplayActivity.java

源码下载：http://download.csdn.net/detail/wirelessqa/5066148