android中sqlite知识点

简单项目结构图

A:自定义StudentSqliteHelper继承SQLiteOpenHelper

public class StudentSqliteHelper extends SQLiteOpenHelper { public StudentSqliteHelper(Context context) { super(context, "student.db", null, 1); } @Override public void onCreate(SQLiteDatabase db) { // TODO Auto-generated method stub //创建表students db.execSQL("create table students(_id integer primary key autoincrement ,name varchar(30) ,sex varchar(5))"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub } }

B:建立实体类Student.java

public class Student { private Integer _id; private String name; private String sex; public Student(Integer _id, String name, String sex) { this._id = _id; this.name = name; this.sex = sex; } public Student(String name, String sex) { this.name = name; this.sex = sex; } @Override public String toString() { return "Student [_id=" + _id + ", name=" + name + ", sex=" + sex + "]"; } public Student() { } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public Integer get_id() { return _id; } public void set_id(Integer _id) { this._id = _id; } }

C：建立StudentDao数据库操作类

public class StudentDao { StudentSqliteHelper helper; public StudentDao(Context context) { // TODO Auto-generated constructor stub helper = new StudentSqliteHelper(context); } // db.execSQL("create table students(_id integer primary key autoincrement ,name varchar(30) ,sex varchar(5))"); public void add(Student s) { SQLiteDatabase db = helper.getWritableDatabase(); db.execSQL("insert into students values(null,?,?)", new Object[] { s.getName(), s.getSex() }); } public void delete(int id) { SQLiteDatabase db = helper.getWritableDatabase(); db.execSQL("delete from students where _id =?", new Object[] { id }); } public void update(Student s) { SQLiteDatabase db = helper.getWritableDatabase(); db.execSQL("update students set name=? ,sex=? where _id=?", new Object[] { s.getName(), s.getSex(), s.get_id() }); } public Student find(int id) { SQLiteDatabase db = helper.getReadableDatabase(); Cursor query = db.rawQuery("select * from students where _id= ?", new String[] { String.valueOf(id) }); Student s = null; if (query.moveToNext()) { // 封装 int _id = query.getInt(query.getColumnIndex("_id")); String name = query.getString(query.getColumnIndex("name")); String sex = query.getString(query.getColumnIndex("sex")); s = new Student(_id, name, sex); } query.close(); return s; } public ArrayList<Student> findAll() { SQLiteDatabase db = helper.getReadableDatabase(); Cursor query = db.rawQuery("select * from students ", null); ArrayList<Student> list = new ArrayList<Student>(); while (query.moveToNext()) { // 封装 int _id = query.getInt(query.getColumnIndex("_id")); String name = query.getString(query.getColumnIndex("name")); String sex = query.getString(query.getColumnIndex("sex")); list.add(new Student(_id, name, sex)); } query.close(); return list; } }

D:测试

public class StudentTest extends AndroidTestCase { public void test1() { StudentDao dao = new StudentDao(getContext()); dao.add(new Student("qishuichixi", "man")); System.out.println("插入完成1"); dao.add(new Student("yuluochanganjie", "man")); System.out.println("插入完成2"); } public void test2() { StudentDao dao = new StudentDao(getContext()); dao.delete(1); System.out.println("删除完成..."); } public void test3() { StudentDao dao = new StudentDao(getContext()); dao.update(new Student(2, "luowenli", "gril")); System.out.println("更新完成"); } public void test4() { StudentDao dao = new StudentDao(getContext()); Student s = dao.find(2); System.out.println(s.toString()); } public void test5() { StudentDao dao = new StudentDao(getContext()); ArrayList<Student> list = dao.findAll(); for (Student s : list) System.out.println(s.toString()); } }

注意在清单文件中配置指令集代码

运行效果截图

下载demo链接 http://download.csdn.net/detail/qq_30266985/9686330

框架ormlite知识链接 http://blog.csdn.net/lmj623565791/article/details/39121377