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; } }