Android关系型数据库应用——电话（短信）黑名单

1.打开数据库，创建数据表；

2.对数据进行crud（Create Read Update Delete）；

1.打开数据库，创建数据表；

1.SQLiteOpenHelper

2.SQLiteDatabase

.execSQL("create table blacknumber (_id integer primary key autoincrement, number varchar(20))");

2.对数据进行crud（Create Read Update Delete）；

1.增：db.execSQL("insert into blacknumber (number) values(?)", new Object[]{number});

2.删：db.execSQL("delete from blacknumber where number = ?", new Object[]{number});

3.改：db.execSQL("update blacknumber set number = ? where number = ?", new Object[]{newnumber,oldnumber})

4.查：Cursor cursor = db.rawQuery("select * from blacknumber where number =?", new String[]{number});

5.查所有：Cursor cursor = db.rawQuery("select number from blacknumber", null);

1.打开数据库，创建数据表；

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

public class BlackNumberDBOpenHelper extends SQLiteOpenHelper {

public BlackNumberDBOpenHelper(Context context) {
super(context, "blacknumber.db", null, 1);

}

/**
* 数据库第一次被创建的时候 调用oncreate()
* 初始化数据库表结构的操作
*/
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table blacknumber (_id integer primary key autoincrement, number varchar(20))");
}

/**
* 数据库已经操作 并且 新的数据库的版本 大于 旧的数据库的版本
* 数据库的表结构信息的更新
*/
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}

}

2.对数据进行crud（Create Read Update Delete）；

public class BlackNumberDao {
BlackNumberDBOpenHelper helper ;

public BlackNumberDao(Context context) {
helper = new BlackNumberDBOpenHelper(context);
}

/**
* 添加一条黑名单号码
*/
public void add(String number){
if(find(number)){
return ;
}
SQLiteDatabase db  = helper.getWritableDatabase();
if(db.isOpen()){
db.execSQL("insert into blacknumber (number) values(?)", new Object[]{number});
db.close();
}
}

/**
* 删除一条黑名单的数据
*/
public void delete(String number){
SQLiteDatabase db  = helper.getWritableDatabase();
if(db.isOpen()){
db.execSQL("delete from blacknumber where number = ?", new Object[]{number});
db.close();
}
}

/**
* 更改一条黑名单的号码
*/
public void update(String oldnumber,String newnumber){
SQLiteDatabase db  = helper.getWritableDatabase();
if(db.isOpen()){
db.execSQL("update blacknumber set number = ? where number = ?", new Object[]{newnumber,oldnumber});
db.close();
}
}

/**
* 查询一条黑名单号码
*/
public boolean find(String number){
boolean result =false;
SQLiteDatabase db  = helper.getReadableDatabase();
if(db.isOpen()){
Cursor cursor = db.rawQuery("select * from blacknumber where number =?", new String[]{number});
if(cursor.moveToFirst()){
result = true;
}
cursor.close();
db.close();
}
return result;
}

/**
* 查找全部黑名单号码
*/
public List<String> findAll(){
List<String> numbers = new ArrayList<String>();
SQLiteDatabase db  = helper.getReadableDatabase();
if(db.isOpen()){
Cursor cursor = db.rawQuery("select number from blacknumber", null);
while (cursor.moveToNext()) {
numbers.add( cursor.getString(0));
}
cursor.close();
db.close();
}
return numbers;
}
}