如何获取所选id'；android sqlite数据库中的s值？
我使用AndroidSQLite数据库创建了一个示例应用程序，我的要求是（请不要点击此链接）。我使用下面的代码来实现这一点 MainClass.java如何获取所选id'；android sqlite数据库中的s值？,android,sqlite,Android,Sqlite,我使用AndroidSQLite数据库创建了一个示例应用程序，我的要求是（请不要点击此链接）。我使用下面的代码来实现这一点 MainClass.java public class MainClass extends Activity implements OnClickListener { Button NUM_INPUT; EditText enter_NUM; int number; DatabaseHandler db = new DatabaseHand
public class MainClass extends Activity implements OnClickListener {
Button NUM_INPUT;
EditText enter_NUM;
int number;
DatabaseHandler db = new DatabaseHandler(this);
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.sai_answers_home);
NUM_INPUT = (Button) findViewById(R.id.answerButton);
enter_NUM = (EditText) findViewById(R.id.saiAnssersEditText);
NUM_INPUT.setOnClickListener(this);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (v.getId() == R.id.answerButton) {
number = Integer.parseInt(this.enter_NUM.getText().toString());
// /System.out.println("EDITTEXTVALUE" + number);
Log.d("Reading: ", "Reading all contacts..");
List<Contact> contacts = db.getAllContacts(number);
for (Contact cn : contacts) {
String log = "Id: " + cn.getID() + " ,Name: " + cn.getName();
// Writing Contacts to log
Log.d("Name: ", log);
}
db.close();
}
}
}
public class DatabaseHandler extends SQLiteOpenHelper {
// The Android's default system path of your application database.
private static String DB_PATH = "/data/data/com.sqlite.example/databases/";
private static String DB_NAME = "answers";
private SQLiteDatabase myDataBase;
private final Context myContext;
String myPath;
/**
* Constructor Takes and keeps a reference of the passed context in order to
* access to the application assets and resources.
*
* @param context
*/
public DatabaseHandler(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own
* database.
* */
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
if (dbExist) {
// do nothing - database already exist
} else {
// By calling this method and empty database will be created into
// the default system path
// of your application so we are gonna be able to overwrite that
// database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each
* time you open the application.
*
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase() {
SQLiteDatabase checkDB = null;
try {
myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
} catch (SQLiteException e) {
// database does't exist yet.
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created
* empty database in the system folder, from where it can be accessed and
* handled. This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException {
// Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
// Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException {
// Open the database
myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if (myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
// Add your public helper methods to access and get content from the
// database.
// You could return cursors by doing "return myDataBase.query(....)" so it'd
// be easy
// to you to create adapters for your views.
public List<Contact> getAllContacts(int muNumber) {
List<Contact> contactList = new ArrayList<Contact>();
// Select All Query
String selectQuery = "SELECT * FROM ANSWER WHERE ID= " + muNumber;
System.out.println("QUERY STRING IS......>>>>>> " + selectQuery);
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Contact contact = new Contact();
contact.setID(Integer.parseInt(cursor.getString(0)));
contact.setName(cursor.getString(1));
// contact.setPhoneNumber(cursor.getString(2));
// Adding contact to list
contactList.add(contact);
} while (cursor.moveToNext());
}
// return contact list
return contactList;
}
}
public类MainClass扩展活动实现OnClickListener{
按钮数输入；
编辑文本输入_NUM；
整数；
DatabaseHandler db=新的DatabaseHandler（此）；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
//TODO自动生成的方法存根
super.onCreate（savedInstanceState）；
setContentView（R.layout.sai_answers_home）；
NUM_INPUT=（按钮）findviewbyd（R.id.answerButton）；
输入_NUM=（EditText）findViewById（R.id.saiAnssersEditText）；
NUM_INPUT.setOnClickListener（此）；
}
@凌驾
公共void onClick（视图v）{
//TODO自动生成的方法存根
if（v.getId（）==R.id.answerButton）{
number=Integer.parseInt（this.enter_NUM.getText（）.toString（））；
///System.out.println（“EDITTEXTVALUE”+数字）；
日志d（“读取：”，“读取所有联系人…”）；
列表联系人=db.getAllContacts（编号）；
用于（联系人cn:联系人）{
字符串log=“Id:”+cn.getID（）+”，名称：“+cn.getName（）；
//将联系人写入日志
Log.d（“名称：”，Log）；
}
db.close（）；
}
}
}
public class MainClass extends Activity implements OnClickListener {
Button NUM_INPUT;
EditText enter_NUM;
int number;
DatabaseHandler db = new DatabaseHandler(this);
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.sai_answers_home);
NUM_INPUT = (Button) findViewById(R.id.answerButton);
enter_NUM = (EditText) findViewById(R.id.saiAnssersEditText);
NUM_INPUT.setOnClickListener(this);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (v.getId() == R.id.answerButton) {
number = Integer.parseInt(this.enter_NUM.getText().toString());
// /System.out.println("EDITTEXTVALUE" + number);
Log.d("Reading: ", "Reading all contacts..");
List<Contact> contacts = db.getAllContacts(number);
for (Contact cn : contacts) {
String log = "Id: " + cn.getID() + " ,Name: " + cn.getName();
// Writing Contacts to log
Log.d("Name: ", log);
}
db.close();
}
}
}
public class DatabaseHandler extends SQLiteOpenHelper {
// The Android's default system path of your application database.
private static String DB_PATH = "/data/data/com.sqlite.example/databases/";
private static String DB_NAME = "answers";
private SQLiteDatabase myDataBase;
private final Context myContext;
String myPath;
/**
* Constructor Takes and keeps a reference of the passed context in order to
* access to the application assets and resources.
*
* @param context
*/
public DatabaseHandler(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own
* database.
* */
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
if (dbExist) {
// do nothing - database already exist
} else {
// By calling this method and empty database will be created into
// the default system path
// of your application so we are gonna be able to overwrite that
// database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each
* time you open the application.
*
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase() {
SQLiteDatabase checkDB = null;
try {
myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
} catch (SQLiteException e) {
// database does't exist yet.
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created
* empty database in the system folder, from where it can be accessed and
* handled. This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException {
// Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
// Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException {
// Open the database
myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if (myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
// Add your public helper methods to access and get content from the
// database.
// You could return cursors by doing "return myDataBase.query(....)" so it'd
// be easy
// to you to create adapters for your views.
public List<Contact> getAllContacts(int muNumber) {
List<Contact> contactList = new ArrayList<Contact>();
// Select All Query
String selectQuery = "SELECT * FROM ANSWER WHERE ID= " + muNumber;
System.out.println("QUERY STRING IS......>>>>>> " + selectQuery);
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Contact contact = new Contact();
contact.setID(Integer.parseInt(cursor.getString(0)));
contact.setName(cursor.getString(1));
// contact.setPhoneNumber(cursor.getString(2));
// Adding contact to list
contactList.add(contact);
} while (cursor.moveToNext());
}
// return contact list
return contactList;
}
}
公共类DatabaseHandler扩展了SQLiteOpenHelper{
//应用程序数据库的Android默认系统路径。
私有静态字符串DB_PATH=“/data/data/com.sqlite.example/databases/”；
私有静态字符串DB_NAME=“answers”；
私有SQLiteDatabase-myDataBase；
私有最终上下文myContext；
字符串myPath；
/**
*构造函数获取并保留所传递上下文的引用，以便
*访问应用程序资产和资源。
*
*@param上下文
*/
公共数据库处理程序（上下文）{
super（上下文，DB_名称，null，1）；
this.myContext=上下文；
}
/**
*在系统上创建一个空数据库，并用自己的数据库重写它
*数据库。
* */
public void createDataBase（）引发IOException{
布尔值dbExist=checkDataBase（）；
if（dbExist）{
//不执行任何操作-数据库已存在
}否则{
//通过调用此方法，空数据库将被创建到
//默认系统路径
//你的应用程序，所以我们可以覆盖它
//数据库与我们的数据库。
这是.getReadableDatabase（）；
试一试{
copyDataBase（）；
}捕获（IOE异常）{
抛出新错误（“复制数据库时出错”）；
}
}
}
/**
*检查数据库是否已存在，以避免每次重新复制文件
*打开应用程序的时间。
*
*@如果存在则返回true，如果不存在则返回false
*/
私有布尔校验数据库（）{
SQLiteDatabase checkDB=null；
试一试{
myPath=DB_PATH+DB_NAME；
checkDB=SQLiteDatabase.openDatabase（myPath，null，
SQLiteDatabase.OPEN_READONLY）；
}catch（sqlitee异常）{
//数据库还不存在。
}
if（checkDB！=null）{
checkDB.close（）；
}
return checkDB！=null？true:false；
}
/**
*将数据库从本地资产文件夹复制到刚创建的
*系统文件夹中的空数据库，从中可以访问和
*已处理。这是通过传输ByTestStream来完成的。
* */
私有void copyDataBase（）引发IOException{
//打开本地数据库作为输入流
InputStream myInput=myContext.getAssets（）.open（DB_NAME）；
//刚创建的空数据库的路径
字符串outFileName=DB_路径+DB_名称；
//打开空数据库作为输出流
OutputStream myOutput=新文件OutputStream（outFileName）；
//将字节从输入文件传输到输出文件
字节[]缓冲区=新字节[1024]；
整数长度；
而（（长度=myInput.read（缓冲区））>0）{
写入（缓冲区，0，长度）；
}
//关闭溪流
myOutput.flush（）；
myOutput.close（）；
myInput.close（）；
}
public void openDataBase（）引发SQLException{
//打开数据库
myPath=DB_PATH+DB_NAME；
myDataBase=SQLiteDatabase.openDatabase（myPath，null，
SQLiteDatabase.OPEN_READONLY）；
}
@凌驾
公共同步作废关闭（）{
if（myDataBase！=null）
myDataBase.close（）；
super.close（）；
}
@凌驾
public void onCreate（SQLiteDatabase db）{
}
@凌驾
public void onUpgrade（SQLiteDatabase db，int-oldVersion，int-newVersion）{
}
//添加公共助手方法以访问和获取
//数据库。
//您可以通过执行“returnmydatabase.query（..”）来返回游标，因此
//放轻松
//为您的视图创建适配器。
公共列表getAllContacts（int muNumber）{
List contactList=new ArrayList（）；
//选择所有查询
String selectQuery=“SELECT*FROM ANSWER WHERE ID=“+muNumber；
System.out.println(