SQLiteDatabase的使用

新建DBHeler.JAVA

package com.hixin.db;

import java.util.ArrayList;
import java.util.HashMap;

import com.hixin.contact.User;

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

public class DBHelper extends SQLiteOpenHelper{
    public final static  String  DB_NAME = "contact";
    public final static  int VERSION = 1;
    private static DBHelper instance = null;
    private SQLiteDatabase db;
    
    //单例模式
    private DBHelper(Context context) {
        super(context,DB_NAME,null,VERSION);
    }
    
    public static DBHelper getInstance(Context context) {
        if(instance == null) {
            instance = new DBHelper(context);
        }
        return instance;
    }
    private void openDatabase() {
        if(db == null) {
            db = this.getReadableDatabase();
        }
    }
    
    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
         StringBuffer tableCreate = new StringBuffer();
         tableCreate.append("create table user (_id integer primary key autoincrement,")
         .append("name text,")
         .append("mobilephone text,")
         .append("familyphone text,")
         .append("officephone text,")
         .append("position text,")
         .append("company text,")
         .append("address text,")
         .append("email text,")
         .append("othercontact text,")
         .append("zipcode text,")
         .append("remark text,")
         .append("imageid int)");
         
         db.execSQL(tableCreate.toString());
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        String sql = "drop table if exists user";
        db.execSQL(sql);
        onCreate(db);
    }
    
    public long save(User user) {
        openDatabase();
        ContentValues value = new ContentValues();
        value.put("name", user.username);
        value.put("mobilephone", user.mobilePhone);
        value.put("familyphone", user.familyPhone);
        value.put("officephone", user.officePhone);
        value.put("position", user.position);
        value.put("address", user.address);
        value.put("email", user.email);
        value.put("othercontact", user.otherContact);
        value.put("zipcode", user.zipCode);
        value.put("remark", user.remark);
        value.put("imageid", user.imageId);
        
        return db.insert("user", null, value);
    }
    
    public ArrayList getUserList() {
        openDatabase();
        Cursor cursor = db.query("user", null, null, null, null, null, null);
        ArrayList list = new ArrayList();
        while (cursor.moveToNext()) {
                HashMap map = new HashMap();
                map.put("imageid", cursor.getInt(cursor.getColumnIndex("imageid")));
                map.put("name", cursor.getString(cursor.getColumnIndex("name")));
                map.put("mobilephone", cursor.getString(cursor.getColumnIndex("mobilephone")));
                list.add(map);
        }
        return list;
    }

}

主函数中调用 
    //save user to database
    DBHelper.getInstance(MainActivity.this).save(user);

save()调用openDatabase(),如果数据库不存在，则自动调用数据库的onCreate（）

//检索数据库

ArrayList data = DBHelper.getInstance(this).getUserList();

tv_name.setText((CharSequence) ((HashMap) data.get(position)).get("name"));

另外一种版本

package com.example.healthembed;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

import com.example.healthembed.dummy.BloodPre;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;

public class DatabaseHelper extends SQLiteOpenHelper {
     
    private static final String DB_NAME = "person.db"; //数据库名称
    private static final int version = 1; //数据库版本
    private static DatabaseHelper instance = null;
    private SQLiteDatabase db;

    //单例模式
   
    public static DatabaseHelper getInstance(Context context) {
        if(instance == null) {
            instance = new DatabaseHelper(context);
        }
        return instance;
    }
    private void openDatabase() {
        if(db == null) {
            db = this.getReadableDatabase();
        }
    }
    public DatabaseHelper(Context context) {
        super(context, DB_NAME, null, version);
    }
 
    
    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        /* StringBuffer tableCreate = new StringBuffer();
         tableCreate.append("create table user (_id integer primary key autoincrement,")
         .append("hp int,")
         .append("lp int)");
         db.execSQL(tableCreate.toString());
         */
         String tableCreate = new String();
         tableCreate="create table user (_id integer primary key autoincrement,name varchar(16),pdate text,hp int,lp int)";
         db.execSQL(tableCreate);
         
//         Toast.makeText(MyApplication.getContext(), "数据保存成功", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        String sql = "drop table if exists user";
        db.execSQL(sql);
        onCreate(db);
    }
    
    public long save(BloodPre user) {
        openDatabase();
        ContentValues value = new ContentValues();
        value.put("name", user.name);
        value.put("pdate",user.time);
        value.put("hp", user.highp);
        value.put("lp", user.lowp); 
        return db.insert("user", null, value);
    }
    
     public ArrayList getUserList() {
        openDatabase();
        Cursor cursor = db.query("user", null, null, null, null, null, null);
        ArrayList<Map> list = new ArrayList();
        while (cursor.moveToNext()) {
                HashMap map = new HashMap();
                map.put("name", cursor.getInt(cursor.getColumnIndex("name")));
                map.put("pdate", cursor.getString(cursor.getColumnIndex("pdate")));
                map.put("hp", cursor.getInt(cursor.getColumnIndex("hp")));
                map.put("lp", cursor.getInt(cursor.getColumnIndex("lp")));
                list.add(map);
        }
        return list;
    }
}

 封装性更好的，适合建立多个表！

package com.example.health.util;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.example.health.bp.DatabaseHelper;

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

/**
 * @author wuzhixin
 * 有if语句的地方添加 else if代码就行
 * 目的在于用一个SQLiteOpenHelper子类创建多个表，并且表之间是独立的，不会一下在创建多个表
 */
public class GeneralDbHelper extends SQLiteOpenHelper{

        private static final String DB_NAME = "person.db"; //数据库名称
        private static final int version = 1; //数据库版本
        private static GeneralDbHelper instance = null;
        private SQLiteDatabase db;
        private Object bean;

        //单例模式
       
        public static GeneralDbHelper getInstance(Context context,Object userType) {
            if(instance == null) {
                instance = new GeneralDbHelper(context,userType);
            }
            return instance;
        }
        private void openDatabase() {
            if(db == null) {
                db = this.getReadableDatabase();
            }
        }
        public GeneralDbHelper (Context context,Object userType) {            
            super(context, DB_NAME, null, version);
            this.bean = userType;
        }
     
        
        /* (non-Javadoc)
         * @see android.database.sqlite.SQLiteOpenHelper#onCreate(android.database.sqlite.SQLiteDatabase)
         */
        @Override
        public void onCreate(SQLiteDatabase db) {
            // TODO Auto-generated method stub
            /* StringBuffer tableCreate = new StringBuffer();
             tableCreate.append("create table user (_id integer primary key autoincrement,")
             .append("hp int,")
             .append("lp int)");
             db.execSQL(tableCreate.toString());
             */
                String tableCreate = new String();
             if(bean instanceof User) {
                 tableCreate = "CREATE TABLE zhongduanuser (shenfennum varchar(255) primary key,name varchar(64),regtime varchar(255),address varchar(255), birthdate varchar(255))";
                 db.execSQL(tableCreate);
             }           
             
//             Toast.makeText(MyApplication.getContext(), "数据保存成功", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            // TODO Auto-generated method stub
             if(bean instanceof User) {
                String sql = "drop table if exists zhongduanuser";
                 db.execSQL(sql);
             }
            onCreate(db);
        }
        
        public long save(Object obj) {
            openDatabase();
            ContentValues value = new ContentValues();
            if(obj  instanceof User) {
                /*private String shenfennum;
                private String name;
                private String regtime;
                private String address;
                private String birthdate;*/
                
                value.put("shenfennum", ((User)obj).getShenfennum());
                value.put("name", ((User)obj).getName());
                value.put("regtime", ((User)obj).getRegtime());
                value.put("address", ((User)obj).getAddress());
                value.put("birthdate", ((User)obj).getBirthdate());
                return db.insert("zhongduanuser", null, value);
            }else{
                return 0;
            }
   
        }
        
         public List<?> getBeanList() {
            openDatabase();
            if(bean instanceof User) {
                 Cursor cursor = db.query("zhongduanuser", null, null, null, null, null, null);
                 List<User> list = new ArrayList<User>();                 
                 while (cursor.moveToNext()) {
                     User user = new User();
                     user.setShenfennum(cursor.getString(cursor.getColumnIndex("shenfennum")));
                     user.setName(cursor.getString(cursor.getColumnIndex("name")));
                     user.setRegtime(cursor.getString(cursor.getColumnIndex("regtime")));
                     user.setAddress(cursor.getString(cursor.getColumnIndex("address")));
                     user.setBirthdate(cursor.getString(cursor.getColumnIndex("birthdate")));                
                     list.add(user);                      
                }
                return list;
            }
            else {
                return null;
            }

        }
}

保存数据：

//创建数据库，保存用户信息到本地 
for (User suser : app.userList) { 
GeneralDbHelper.getInstance(MyApplication.getContext(), suser).save(suser);
}

使用数据：

User user = new User();
app.userList = GeneralDbHelper.getInstance(MyApplication.getContext(), user).getBeanList();

上面的不能正确使用，下面的这个可以

package com.example.health.util;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;

/**
 * @author wuzhixin
 * 有if语句的地方添加 else if代码就行
 * 目的在于用一个SQLiteOpenHelper子类创建多个表，并且表之间是独立的，不会一下在创建多个表
 */
public class GeneralDbHelper extends SQLiteOpenHelper{

        private static final String DB_NAME = "person.db"; //数据库名称
        private static final int version = 1; //数据库版本
        private static GeneralDbHelper instance = null;
        private SQLiteDatabase db;

        //单例模式
       
        public static GeneralDbHelper getInstance(Context context) {
            if(instance == null) {
                instance = new GeneralDbHelper(context);
            }
            return instance;
        }
        private void openDatabase() {
            if(db == null) {
                db = this.getReadableDatabase();
            }
        }
        public GeneralDbHelper (Context context) {
            super(context, DB_NAME, null, version);        
        }
     
        
        /* (non-Javadoc)
         * @see android.database.sqlite.SQLiteOpenHelper#onCreate(android.database.sqlite.SQLiteDatabase)
         */
        @Override
        public void onCreate(SQLiteDatabase db) {
            // TODO Auto-generated method stub
            /* StringBuffer tableCreate = new StringBuffer();
             tableCreate.append("create table user (_id integer primary key autoincrement,")
             .append("hp int,")
             .append("lp int)");
             db.execSQL(tableCreate.toString());
             */
              

                 String tableCreate1 = "CREATE TABLE zhongduanuser (shenfennum varchar(255) primary key,name varchar(64),regtime varchar(255),address varchar(255), birthdate varchar(255))";
                 db.execSQL(tableCreate1);
                 String tableCreate2="create table xueya2 (_id integer primary key autoincrement,userid varchar(255),regdate varchar(64),shousuo int(11),shuzhang int(11),maibo int(11))";
                 db.execSQL(tableCreate2);

             
//             Toast.makeText(MyApplication.getContext(), "数据保存成功", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            // TODO Auto-generated method stub
        
            String sql1 = "drop table if exists zhongduanuser";
             db.execSQL(sql1);

            String sql2 = "drop table if exists xueya2";
             db.execSQL(sql2);
            onCreate(db);
        }
        
        public long save(Object obj) {
            openDatabase();
            ContentValues value = new ContentValues();
            if(obj  instanceof User) {
                /*private String shenfennum;
                private String name;
                private String regtime;
                private String address;
                private String birthdate;*/
                
                value.put("shenfennum", ((User)obj).getShenfennum());
                value.put("name", ((User)obj).getName());
                value.put("regtime", ((User)obj).getRegtime());
                value.put("address", ((User)obj).getAddress());
                value.put("birthdate", ((User)obj).getBirthdate());
                return db.insert("zhongduanuser", null, value);
            }else if(obj instanceof BloodPre){                
                /*private String userid;  
                 private String time;
                 private int highp;  
                 private int lowp;
                 private int pulse;*/
                value.put("userid", ((BloodPre)obj).getUserid());
                value.put("regdate", ((BloodPre)obj).getTime());
                value.put("shousuo", ((BloodPre)obj).getHighp());
                value.put("shuzhang", ((BloodPre)obj).getLowp());
                value.put("maibo", ((BloodPre)obj).getPulse());
                return db.insert("xueya2", null, value);
            }else{
                return 0;
            }
   
        }
        
         public List<?> getBeanList(Object obj) {
            openDatabase();
            if(obj instanceof User) {
                 Cursor cursor = db.query("zhongduanuser", null, null, null, null, null, null);
                 List<User> list = new ArrayList<User>();                 
                 while (cursor.moveToNext()) {
                     User user = new User();
                     user.setShenfennum(cursor.getString(cursor.getColumnIndex("shenfennum")));
                     user.setName(cursor.getString(cursor.getColumnIndex("name")));
                     user.setRegtime(cursor.getString(cursor.getColumnIndex("regtime")));
                     user.setAddress(cursor.getString(cursor.getColumnIndex("address")));
                     user.setBirthdate(cursor.getString(cursor.getColumnIndex("birthdate")));                
                     list.add(user);                      
                }
                return list;
            }else if(obj instanceof BloodPre){
                 Cursor cursor = db.query("xueya2", null, null, null, null, null, null);
                 List<BloodPre> list = new ArrayList<BloodPre>();                 
                 while (cursor.moveToNext()) {
                     BloodPre bloodpre = new BloodPre();
                     bloodpre.setUserid(cursor.getString(cursor.getColumnIndex("userid")));
                     bloodpre.setTime(cursor.getString(cursor.getColumnIndex("regdate")));
                     bloodpre.setHighp(cursor.getInt(cursor.getColumnIndex("shousuo")));
                     bloodpre.setLowp(cursor.getInt(cursor.getColumnIndex("shuzhang")));
                     bloodpre.setPulse(cursor.getInt(cursor.getColumnIndex("maibo")));
                                
                     list.add(bloodpre);                      
                }
                return list;
            }
            else {
                return null;
            }

        }
}

更新的版本：

package com.example.health.util;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;

/**
 * @author wuzhixin
 * 
 * 目的在于用一个SQLiteOpenHelper子类创建多个表
 */
public class GeneralDbHelper extends SQLiteOpenHelper{

        private static final String DB_NAME = "person.db"; //数据库名称
        private static final int version = 1; //数据库版本
        private static GeneralDbHelper instance = null;
        private SQLiteDatabase db;

        //单例模式
       
        public static GeneralDbHelper getInstance(Context context) {
            if(instance == null) {
                instance = new GeneralDbHelper(context);
            }
            return instance;
        }
        private void openDatabase() {
            if(db == null) {
                db = this.getReadableDatabase();
            }
        }
        public GeneralDbHelper (Context context) {
            super(context, DB_NAME, null, version);        
        }
     
        
        /* (non-Javadoc)
         * @see android.database.sqlite.SQLiteOpenHelper#onCreate(android.database.sqlite.SQLiteDatabase)
         */
        @Override
        public void onCreate(SQLiteDatabase db) {
            // TODO Auto-generated method stub
            /* StringBuffer tableCreate = new StringBuffer();
             tableCreate.append("create table user (_id integer primary key autoincrement,")
             .append("hp int,")
             .append("lp int)");
             db.execSQL(tableCreate.toString());
             */
              

                 String tableCreate1 = "CREATE TABLE zhongduanuser (shenfennum varchar(255) primary key,name varchar(64),regtime varchar(255),address varchar(255), birthdate varchar(255))";
                 db.execSQL(tableCreate1);
                 String tableCreate2="create table xueya2 (_id integer primary key autoincrement,userid varchar(255),regdate varchar(64),shousuo int(11),shuzhang int(11),maibo int(11))";
                 db.execSQL(tableCreate2);

             
//             Toast.makeText(MyApplication.getContext(), "数据保存成功", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            // TODO Auto-generated method stub
        
            String sql1 = "drop table if exists zhongduanuser";
             db.execSQL(sql1);

            String sql2 = "drop table if exists xueya2";
             db.execSQL(sql2);
            onCreate(db);
        }
        
        public long save(Object obj) {
            openDatabase();
            ContentValues value = new ContentValues();
            if(obj  instanceof User) {
                /*private String shenfennum;
                private String name;
                private String regtime;
                private String address;
                private String birthdate;*/
                
                value.put("shenfennum", ((User)obj).getShenfennum());
                value.put("name", ((User)obj).getName());
                value.put("regtime", ((User)obj).getRegtime());
                value.put("address", ((User)obj).getAddress());
                value.put("birthdate", ((User)obj).getBirthdate());
                return db.insert("zhongduanuser", null, value);
            }else if(obj instanceof BloodPre){                
                /*private String userid;  
                 private String time;
                 private int highp;  
                 private int lowp;
                 private int pulse;*/
                value.put("userid", ((BloodPre)obj).getUserid());
                value.put("regdate", ((BloodPre)obj).getTime());
                value.put("shousuo", ((BloodPre)obj).getHighp());
                value.put("shuzhang", ((BloodPre)obj).getLowp());
                value.put("maibo", ((BloodPre)obj).getPulse());
                return db.insert("xueya2", null, value);
            }else{
                return 0;
            }
   
        }
        
         public List<?> getBeanList(Object obj) {
            openDatabase();
            if(obj instanceof User) {
                 Cursor cursor = db.query("zhongduanuser", null, null, null, null, null, null);
                 List<User> list = new ArrayList<User>();                 
                 while (cursor.moveToNext()) {
                     User user = new User();
                     user.setShenfennum(cursor.getString(cursor.getColumnIndex("shenfennum")));
                     user.setName(cursor.getString(cursor.getColumnIndex("name")));
                     user.setRegtime(cursor.getString(cursor.getColumnIndex("regtime")));
                     user.setAddress(cursor.getString(cursor.getColumnIndex("address")));
                     user.setBirthdate(cursor.getString(cursor.getColumnIndex("birthdate")));                
                     list.add(user);                      
                }
                return list;
            }else if(obj instanceof BloodPre){
                 Cursor cursor = db.query("xueya2", null, null, null, null, null, null);
                 List<BloodPre> list = new ArrayList<BloodPre>();                 
                 while (cursor.moveToNext()) {
                     BloodPre bloodpre = new BloodPre();
                     bloodpre.setUserid(cursor.getString(cursor.getColumnIndex("userid")));
                     bloodpre.setTime(cursor.getString(cursor.getColumnIndex("regdate")));
                     bloodpre.setHighp(cursor.getInt(cursor.getColumnIndex("shousuo")));
                     bloodpre.setLowp(cursor.getInt(cursor.getColumnIndex("shuzhang")));
                     bloodpre.setPulse(cursor.getInt(cursor.getColumnIndex("maibo")));
                                
                     list.add(bloodpre);                      
                }
                return list;
            }
            else {
                return null;
            }

        }
         
         
         public List<?> getBeanList(Object obj,String userID) {
                openDatabase();
                if(obj instanceof BloodPre){                    
                 
                     String query = "select regdate,shousuo,shuzhang,maibo from xueya2 where userid = "+userID;
                     Cursor cursor = db.query("xueya2", new String[]{"regdate,shousuo,shuzhang,maibo"},"userid=?", new String[]{userID}, null, null, null);
                     List<BloodPre> list = new ArrayList<BloodPre>();                 
                     while (cursor.moveToNext()) {
                         BloodPre bloodpre = new BloodPre();
                         bloodpre.setTime(cursor.getString(cursor.getColumnIndex("regdate")));
                         bloodpre.setHighp(cursor.getInt(cursor.getColumnIndex("shousuo")));
                         bloodpre.setLowp(cursor.getInt(cursor.getColumnIndex("shuzhang")));
                         bloodpre.setPulse(cursor.getInt(cursor.getColumnIndex("maibo")));                                    
                         list.add(bloodpre);                      
                    }
                    return list;
                }
                else {
                    return null;
                }

            }
}

存数据：

//创建数据库，保存用户信息到本地
for (User suser : app.userList) {
GeneralDbHelper.getInstance(MyApplication.getContext()).save(suser);
}

取数据：

User user = new User();
app.userList = (List<User>) GeneralDbHelper.getInstance(MyApplication.getContext()).getBeanList(user);

已有数据库时：

private final String DATABASE_PATH = android.os.Environment
            .getExternalStorageDirectory().getAbsolutePath()
            + "/dictionary";
    //定义数据库的名字
    private final String DATABASE_FILENAME = "dictionary.db";


private SQLiteDatabase openDatabase()
    {
        try
        {
            // 获得dictionary.db文件的绝对路径
            String databaseFilename = DATABASE_PATH + "/" + DATABASE_FILENAME;
            File dir = new File(DATABASE_PATH);
            // 如果/sdcard/dictionary目录中存在，创建这个目录
            if (!dir.exists())
                dir.mkdir();
            // 如果在/sdcard/dictionary目录中不存在
            // dictionary.db文件，则从res
aw目录中复制这个文件到
            // SD卡的目录（/sdcard/dictionary）
            if (!(new File(databaseFilename)).exists())
            {
                // 获得封装dictionary.db文件的InputStream对象
                InputStream is = getResources().openRawResource(
                        R.raw.dictionary);
                FileOutputStream fos = new FileOutputStream(databaseFilename);
                byte[] buffer = new byte[8192];
                int count = 0;
                // 开始复制dictionary.db文件
                while ((count = is.read(buffer)) > 0)
                {
                    fos.write(buffer, 0, count);
                }
                //关闭文件流
                fos.close();
                is.close();
            }
            // 打开/sdcard/dictionary目录中的dictionary.db文件
            SQLiteDatabase database = SQLiteDatabase.openOrCreateDatabase(
                    databaseFilename, null);
            return database;
        }
        catch (Exception e)
        {
        }
        //如果打开出错，则返回null
        return null;
    }