增删改查模板java-数据库增删改查模板-hlxxjava的个人空间-OSCHINA-中文

1、java_-hlxxjava-OSCHINA-中。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 com.template.studentinfosystem.db.StudentDBOpenHelper;import com.template.

2、studentinfosystem.domain.Student;/* 学信息数据库的dao(data access objcet)* 增删改查*/public class StudentDao private StudentDBOpenHelper helper;/* 只有个有参的构造法,要求必须传上下* param context*/public StudentDao(Context context) helper = new StudentDBOpenHelper(context);/* 添加个学* param name 姓名* param sex 性别,male female* ret

3、urn result 添加到数据库的那,-1添加失败*/public long add(String name,String sex)SQLiteDatabase db = helper.getWritableDatabase();/db.execSQL(insert into student (name,sex) values (?,?), new Objectname,sex);ContentValues values =new ContentValues();values.put(name, name);values.put(sex, sex);long result = db.inse

4、rt(student, null, values); /组拼sql语句实现的.带返回值db.close();/释放资源return result;/* 删除个学* param name 姓名* return result 删除了 0 代表删除失败*/public int delete(String name)SQLiteDatabase db = helper.getWritableDatabase();/db.execSQL(delete from student where name=?,new Objectname);int result = db.delete(student, nam

5、e=?, new Stringname);db.close();/释放资源return result;/* 修改个学的性别* param name 姓名* param newsex 新的性别* return 更新了 0更新失败*/public int update(String name,String newsex)SQLiteDatabase db = helper.getWritableDatabase();/db.execSQL(update student set sex =? where name=?,new Objectnewsex,name);ContentValues valu

6、es = new ContentValues();values.put(sex, newsex);int result = db.update(student, values, name=?, new Stringname);db.close();/释放资源return result;/* 查询学的性别* param name 学的姓名* return 学性别 null代表学不存在*/public String find(String name)String sex = null;SQLiteDatabase db = helper.getReadableDatabase();/结果集 游标/

7、Cursor cursor = db.rawQuery(select sex from student where name=?, new Stringname);Cursor cursor = db.query(student, new Stringsex, name=?, new Stringname, null, null, null);boolean result = cursor.moveToNext();if(result)sex = cursor.getString(0);cursor.close();/释放资源db.close();return sex;/* 获取全部的学信息*

8、 return*/public List findAll()List students =new ArrayList();SQLiteDatabase db = helper.getReadableDatabase();/Cursor cursor = db.rawQuery(select name,sex from student, null);Cursor cursor = db.query(student, new Stringname,sex, null, null, null, null, null);while(cursor.moveToNext()String name = cursor.getString(0);String sex = cursor.getString(1);Student s