android SQLiteDatebase 实践

android 平台下建立的一个数据库小实例。实现了数据的增、删、改、通过对话框的形式去修改、删除数据

MdbHelper类:

package training.android.com;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.SQLException;import android.database.sqlite.SQLiteDatabase;import android.util.Log;public class MdbHelper {private SQLiteDatabase mdb;private sqldataHelper mdbhelp;private final Context cxt;public static final String KeyRowID = "_id";public static final String KeyRowname = "StudentName";public static final String KeyRowAge = "StudentAge";public static final String KeyRowClass = "StudentClass";public static final String KeyRowSchool = "StudentSchool";private static final String TableName = "Student";//public MdbHelper(Context ct) {this.cxt = ct;}public MdbHelper open() throws SQLException {mdbhelp = new sqldataHelper(cxt, 1);setMdb(mdbhelp.getWritableDatabase());return this;}public void close() {mdbhelp.close();}public void InsertStudent(int studnetid, String studentname,String studentage, String studentclass, String studentschool) {ContentValues values = new ContentValues();values.put(KeyRowID, studnetid);values.put(KeyRowname, studentname);values.put(KeyRowAge, studentage);values.put(KeyRowClass, studentclass);values.put(KeyRowSchool, studentschool);mdb.insert(TableName, null, values);}public void UpdateStudent(int studentid, String studentname,String studentage, String studentclass, String studentschool) {ContentValues values = new ContentValues();values.put(KeyRowname, studentname);values.put(KeyRowAge, studentage);values.put(KeyRowClass, studentclass);values.put(KeyRowSchool, studentschool);mdb.update(TableName, values, KeyRowID + "=" + studentid, null);}public Cursor simpleStudent(long studentid) throws SQLException {return mdb.query(TableName, new String[] { KeyRowID, KeyRowname,KeyRowAge, KeyRowClass, KeyRowSchool }, KeyRowID + "="+ studentid, null, null, null, null);// return mdb.query(TableName, new String[]{KeyRowID,// KeyRowname,KeyRowAge,KeyRowClass,KeyRowSchool},// KeyRowID+"="+studentid, null, null, null, null);// return mdb.query(TableName, new String[]{KeyRowID,// KeyRowname,KeyRowAge,KeyRowClass,KeyRowSchool},// KeyRowID+"="+studentid, null, null, null, null);}public boolean deletestudent(long rowId) { return mdb.delete(TableName, KeyRowID + "=" + rowId, null) > 0; //(4)}public Cursor fetchMyTableById(long rowId) throws SQLException {return mdb.query(TableName, new String[] { KeyRowID, KeyRowname,KeyRowAge, KeyRowClass, KeyRowSchool }, KeyRowID + "=" + rowId,null, null, null, null);}public Cursor QueryStudentALl() {return mdb.query(TableName, new String[] { KeyRowID, KeyRowname,KeyRowAge, KeyRowClass, KeyRowSchool }, null, null, null, null,null, null);}public void setMdb(SQLiteDatabase mdb) {this.mdb = mdb;}public SQLiteDatabase getMdb() {return mdb;}}

SQLiteOpenHelper继承:

package training.android.com;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;public class sqldataHelper extends SQLiteOpenHelper {private static final String Databasename="SmsStudent";private static final String TableName = "Student";//public static final String KeyRowID = "_id";public static final String KeyRowname = "StudentName";public static final String KeyRowAge = "StudentAge";public static final String KeyRowClass = "StudentClass";public static final String KeyRowSchool = "StudentSchool";private static final String StudentTableSql = "CREATE TABLE IF NOT EXISTS "+ TableName + "(" + KeyRowID + " INTEGER PRINAMARY KEY," + KeyRowname+ " VARCHAR," + KeyRowAge + " VARCHAR," + KeyRowClass + " VARCHAR,"+ KeyRowSchool + " VARCHAR);";private static final String UpdateTableGradSql = "DROP TABLE IF EXISTS"+ TableName;public sqldataHelper(Context context, int version) {super(context, Databasename, null, version);// TODO Auto-generated constructor stub}@Overridepublic void onCreate(SQLiteDatabase db) {// TODO Auto-generated method stubdb.execSQL(StudentTableSql);}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {// TODO Auto-generated method stubdb.execSQL(UpdateTableGradSql);onCreate(db);}}

页面代码：

package training.android.com;import android.app.Activity;import android.app.AlertDialog;import android.content.DialogInterface;import android.content.DialogInterface.OnClickListener;import android.database.Cursor;import android.os.Bundle;import android.view.LayoutInflater;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.AdapterView;import android.widget.EditText;import android.widget.ListView;import android.widget.SimpleCursorAdapter;import android.widget.Toast;import android.widget.AdapterView.OnItemClickListener;//创建人：周昕//创建时间：2010-4-1public class studentdatabase extends Activity {private MdbHelper mdbhelper;public static final String KeyRowID = "_id";public static final String KeyRowname = "StudentName";public static final String KeyRowAge = "StudentAge";public static final String KeyRowClass = "StudentClass";public static final String KeyRowSchool = "StudentSchool";private EditText studentname;private EditText studentage;private EditText studentclass;private EditText studentschool;private String name;private String age;private String Class;private String School; private int Studentid;// private static final String TableName = "Student";///** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);Binddata();}public boolean onCreateOptionsMenu(Menu menu) {super.onCreateOptionsMenu(menu);menu.add("新增");return true;}public boolean onOptionsItemSelected(MenuItem items) {super.onOptionsItemSelected(items);switch (items.getItemId()) {case 0:// Toast.makeText(this, "新增", Toast.LENGTH_SHORT).show();LayoutInflater factory = LayoutInflater.from(this);View myview = factory.inflate(R.layout.addstundet, null);studentname = (EditText) myview.findViewById(R.id.insertstudentname);studentage = (EditText) myview.findViewById(R.id.insertstudentage);studentclass = (EditText) myview.findViewById(R.id.insertstudentclass);studentschool = (EditText) myview.findViewById(R.id.insertstudentschool);OnClickListener click1 = new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stubString name = studentname.getText().toString();String age = studentage.getText().toString();String sclass = studentclass.getText().toString();String school = studentschool.getText().toString();mdbhelper.open();Cursor firstcurss = mdbhelper.QueryStudentALl();int max;int temp = 0;while (firstcurss.moveToNext()) {max = firstcurss.getInt(0);if (temp < max)temp = max;}int maxIntID = temp;mdbhelper.InsertStudent(maxIntID + 1, name, age, sclass,school);Binddata();}};OnClickListener click2 = new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stub}};AlertDialog newstudentdialog = new AlertDialog.Builder(this).create();newstudentdialog.setView(myview);newstudentdialog.setButton("确定", click1);newstudentdialog.setButton2("取消", click2);newstudentdialog.show();break;}return false;}public void Binddata() {mdbhelper = new MdbHelper(this);mdbhelper.open();String[] student = new String[] { KeyRowID, KeyRowname, KeyRowAge,KeyRowClass, KeyRowSchool };int[] arraystudent = new int[] { R.id.studentid, R.id.studentname,R.id.studentage, R.id.studentclass, R.id.studenschool };Cursor curs = mdbhelper.QueryStudentALl();startManagingCursor(curs);SimpleCursorAdapter ad = new SimpleCursorAdapter(this,R.layout.list_row, curs, student, arraystudent);// setListAdapter(ad);如果继承ListActivityListView list = (ListView) findViewById(R.id.list);list.setAdapter(ad);OnItemClickListener clicklisterner = new OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) {// TODO Auto-generated method stubStudentid= arg2 + 1;Cursor simplestuent = mdbhelper.fetchMyTableById(Studentid);while (simplestuent.moveToNext()) {name = simplestuent.getString(1);age = simplestuent.getString(2);Class = simplestuent.getString(3);School = simplestuent.getString(4);}LayoutInflater factory = LayoutInflater.from(studentdatabase.this);View myview = factory.inflate(R.layout.addstundet, null);studentname = (EditText) myview.findViewById(R.id.insertstudentname);studentage = (EditText) myview.findViewById(R.id.insertstudentage);studentclass = (EditText) myview.findViewById(R.id.insertstudentclass);studentschool = (EditText) myview.findViewById(R.id.insertstudentschool);studentname.setText(name);studentage.setText(age);studentclass.setText(Class);studentschool.setText(School);//Toast.makeText(studentdatabase.this, "您当前选择的编号为：" + Studentid,//Toast.LENGTH_SHORT).show();OnClickListener click1 = new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stubString name = studentname.getText().toString();String age = studentage.getText().toString();String sclass = studentclass.getText().toString();String school = studentschool.getText().toString();mdbhelper.open();mdbhelper.UpdateStudent(Studentid, name, age, sclass, school);Binddata();}};OnClickListener click2 = new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stub}};OnClickListener click3=new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stubmdbhelper.open();if(mdbhelper.deletestudent(Studentid)){Toast.makeText(studentdatabase.this, "编号为"+Studentid+"学生删除成功", Toast.LENGTH_SHORT).show();Binddata();}}};AlertDialog newstudentdialog = new AlertDialog.Builder(studentdatabase.this).create();newstudentdialog.setView(myview);newstudentdialog.setButton("更新", click1);newstudentdialog.setButton2("取消", click2);newstudentdialog.setButton3("删除", click3);newstudentdialog.show();}};list.setOnItemClickListener(clicklisterner);// mdbhelper.close();}}

mail.xml:

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical" android:layout_width="fill_parent"android:layout_height="fill_parent"><ListView android:id="@+id/list" android:layout_width="fill_parent"android:layout_height="wrap_content" /></LinearLayout>

addstundet.xml:

<?xml version="1.0" encoding="UTF-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical" android:layout_width="fill_parent"android:layout_height="wrap_content"><TableLayout android:id="@+id/TableLayout01"android:layout_width="wrap_content" android:layout_height="wrap_content"><TableRow android:id="@+id/TableRow01" android:orientation="horizontal"android:layout_width="wrap_content" android:layout_height="wrap_content"><TextView android:id="@+id/txtname" android:layout_width="100px"android:layout_marginLeft="20px" android:layout_height="wrap_content"android:text="姓名"></TextView><EditText android:id="@+id/insertstudentname"android:layout_width="150px" android:layout_height="wrap_content"android:text=""></EditText></TableRow><TableRow android:id="@+id/TableRow02" android:layout_width="wrap_content"android:layout_height="wrap_content"><TextView android:id="@+id/txtage" android:layout_width="100px"android:layout_marginLeft="20px" android:layout_height="wrap_content"android:text="年龄"></TextView><EditText android:id="@+id/insertstudentage"android:layout_width="150px" android:layout_height="wrap_content"android:text=""></EditText></TableRow><TableRow android:id="@+id/TableRow03" android:layout_width="wrap_content"android:layout_height="wrap_content"><TextView android:id="@+id/txtclass" android:layout_width="100px"android:layout_marginLeft="20px" android:layout_height="wrap_content"android:text="班级"></TextView><EditText android:id="@+id/insertstudentclass"android:layout_width="150px" android:layout_height="wrap_content"android:text=""></EditText></TableRow><TableRow android:id="@+id/TableRow03" android:layout_width="wrap_content"android:layout_height="wrap_content"><TextView android:id="@+id/txtschool" android:layout_width="100px"android:layout_marginLeft="20px" android:layout_height="wrap_content"android:text="学校"></TextView><EditText android:id="@+id/insertstudentschool"android:layout_width="150px" android:layout_height="wrap_content"android:text=""></EditText></TableRow><TableRow android:id="@+id/TableRow03" android:orientation="horizontal"android:layout_width="wrap_content" android:layout_height="wrap_content"></TableRow></TableLayout></LinearLayout>

list_row.xml:

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