大家好我正在尝试将信息添加到数据库但是我收到运行时错误。我是android和数据库的新手。如果有人可以提供帮助，那就太棒了，因为这是一个功课，而且我被困住了。
public class Home extends MenuActivity {
static int counter = 0;
String url;
String date;
String content;
int countMe = 0;
int i = 0;
StringBuilder sb;
List<String> str;
List<WebPage> pages = new ArrayList<WebPage>();
long myDate;
DatabaseHandler dh;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home);
regularExpresionStrings();
dh = new DatabaseHandler(this);
// dh.addWarrior(new Warrior(1, "Kenobi", "high", 50 , 30, "kenobi"));
dh.addWebPage(pages);
Cursor cursor = dh.getAllAsCursor();
String[] cols = new String[] {DatabaseHandler.url};
int[] to = new int[] {R.id.imageView2};
// sca = new SimpleCursorAdapter(this, R.layout.home, cursor, cols, to, 2);
//new SimpleCursorAdapter(context, layout, c, from, to, flags)
// mainListView.setAdapter(sca);
}
/**
* When this method is called we try to find a file in the sandbox area that
* matches the DDMMYY extracted from the picker.
*
* @param filename the name of the file (built using the DatePicker info)
* @return the content of the file, or an error message if not found
*/
private String load()
{
try
{
Log.d("Home", " in the load method");
// final FileInputStream fis = openFileInput(filename);
final InputStream fis = getResources().openRawResource(R.raw.pages);
final BufferedReader reader = new BufferedReader(new InputStreamReader(fis));
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null)
{
sb.append(line);
}
reader.close();
fis.close();
return sb.toString();
} catch (Exception ex) {
return "No entry exists for this file";
}
}
private String regularExpresionStrings()
{
Log.d("Home222", " in the regularExpresionStrings method");
String content = load();
String[] parts = content.split("</html>");
String pa = "";
SharedPreferences.Editor editor = getPreferences(MODE_PRIVATE).edit();
for(int i=0; i<parts.length; i++)
{
pa = new String(parts[i] + "</html>");
Log.d("Page" + (i + 1), pa);
if(pa.contains("Address:"))
{
url = pa.substring(pa.indexOf("http"), pa.indexOf("html") + 4);
Log.d("Address" + (i + 1), url);
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
Editor ed = prefs.edit();
ed.putString("URL", url);
ed.commit();
// getPreferences(MODE_PRIVATE).edit().putString("URL ", url).commit();
}
if(pa.contains("Date:"))
{
date = pa.substring(pa.indexOf("Date:") + 5, pa.indexOf("Date:") + 18);
myDate = Long.parseLong(date);
Log.d("Date" + (i + 1), date);
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
Editor ed = prefs.edit();
ed.putString("Date", myDate + "");
ed.commit();
// getPreferences(MODE_PRIVATE).edit().putString("Date ", myDate + "").commit();
}
content = pa.substring(pa.indexOf("<!DOCTYPE html>"), pa.indexOf("</html>")) + "</html>";
Log.d("Content" + (i + 1), content);
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
Editor ed = prefs.edit();
ed.putString("Content", content);
ed.commit();
// getPreferences(MODE_PRIVATE).edit().putString("Content ", content).commit();
WebPage webPages = new WebPage(i++, url, content, myDate);
pages.add(webPages);
}
Log.d("WebOff","File successfully imported");
return content;
}
}
public class WebPage {
/**
* id represent the id of the table.
*/
private int id;
/**
* url represent the url of the web page.
*/
private String url;
/**
* source represent the source of the web page.
*/
private String source;
/**
* date represent a date
*/
private long date;
public WebPage() {
}
/**
* WebPage() creates a web page object
* @param url set the current url with the passed one.
* @param source set the current source with the passed one.
* @param date set the current date with the passed one.
*/
public WebPage(int id, String url, String source, long date) {
this.url = url;
this.source = source;
this.date = date;
Log.d("WebOff", "WebPage object created");
}
/**
* @return the id
*/
public int getId() {
return id;
}
// /**
// * @param id the id to set
// */
public void setId(int id) {
this.id = id;
}
/**
* getUrl() gets the url of the web page.
* @return the url
*/
public String getUrl() {
return url;
}
/**
* setUrl() sets the url of the web page.
* @param url to set
*/
public void setUrl(String url) {
this.url = url;
}
/**
* getSource() gets the source fo the web page.
* @return the source
*/
public String getSource() {
return source;
}
/**
* setSource() sets the source of the web page.
* @param source to set
*/
public void setSource(String source) {
this.source = source;
}
/**
* getDate() gets the date.
* @return the date
*/
public long getDate() {
return date;
}
/**
* setDate() sets the date.
* @param date to set
*/
public void setDate(long date) {
this.date = date;
}
public void webPage() {
Log.d("Debug","" + this.url);
Log.d("Debug", this.source);
Log.d("Debug", this.date + "");
}
}
public class DatabaseHandler extends SQLiteOpenHelper {
/**
* The name of the database
*/
private static final String DATABASE_NAME = "WebOff.db";
/**
* The name of the (only) table.
*/
private static final String TABLE_NAME = "pages";
/**
* The name of the first column (ID)
*/
static final int _id = 0;
/**
* The name of the second column (url)
*/
static final String url = "url";
/**
* The name of the third column (source)
*/
static final String source = "source";
static final int date = 0;
// attack
/**
* A constructor which builds a DatabaseHandler object. Note that calling
* the constructor does not create a database. This does not happen until
* the first call to getReadableDatabase() or getWriteableDatabase()
*
* @param context
* In this case, a reference to WarriorActivity
*/
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, 1);
}
/**
* This method is called when the database is created for the first time.
* This is where the creation of tables and the initial population of the
* tables should happen.
*/
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_NAME + "("
+ _id + " INTEGER PRIMARY KEY,"
+ url + " URL,"
+ source + " Source, "
+ date + " Date" + ")";
db.execSQL(CREATE_CONTACTS_TABLE);
Log.d("WebOff", "Database created successful");
}
/**
* Called when the database needs to be upgraded. Only relevant when you
* have multiple versions of the database scheme in play.
*
*/
@Override
public void onUpgrade(SQLiteDatabase db, int oldNum, int newNum) {
// Drop older table if exist and create fresh
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
/**
* Use this method to add a Warrior to the database.
*
* @param Warrior
* the Warrior you want to add
*/
public void addWebPage(List<WebPage> webPage) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
ByteArrayOutputStream out = new ByteArrayOutputStream();
// for(int i=0; i<webPage.size(); i++)
// {
// // Iterate through the list, adding the information stored within the WebPage object to the databese.
// values.put("text", webPage.indexOf(i));
// }
// values.put(_id + "", webPage.getId());
// values.put(url, webPage.getUrl());
// values.put(source, webPage.getSource());
// values.put(date +"", webPage.getDate() +"");
db.insert(TABLE_NAME, null, values);
db.close();
Log.d("WebOff", "Database populated");
}
/**
* Use this method to get all of the Warriors in the database.
*
* @return a list of Warrior objects, one per row
*/
public List<WebPage> getAll() {
List<WebPage> list = new ArrayList<WebPage>();
String selectQuery = "SELECT * FROM " + TABLE_NAME;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
if (cursor.moveToFirst()) {
do {
WebPage webPage = new WebPage(cursor.getInt(0),
cursor.getString(1),
cursor.getString(2),
cursor.getInt(3));
list.add(webPage);
} while (cursor.moveToNext());
}
cursor.close();
db.close();
return list;
}
/**
* Use this method to get a Cursor object that points at all the Warriors in
* the database
*
* @return a Cursor object pointing at all Warriors in db
*/
public Cursor getAllAsCursor() {
String selectQuery = "SELECT * FROM " + TABLE_NAME;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
//db.close();
return cursor;
}
/**
* Use this method to remove all of the Warriors from the database. This is
* useful when experimenting. After dropping all tables, the initial state
* of the database is re-created.
*/
public void removeAll() {
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
/**
* This method removes one WebPage from the database.
*
* @param WebPage
* the WebPage to remove
*/
public void deleteWebPage(WebPage webPage) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_NAME, _id + " = ?",
new String[] { String.valueOf(webPage.getId()) });
db.close();
}
/**
* This method updates the data stored in the database for one Warrior.
*
* @param Warrior
* the Warrior to update
* @return the number of rows affected
*/
public int updateWebPage(WebPage webPage) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(_id + "", webPage.getId());
values.put(url, webPage.getUrl());
values.put(source, webPage.getSource());
values.put(date + "", webPage.getDate());
return db.update(TABLE_NAME, values, _id + " = ?",
new String[] { String.valueOf(webPage.getId()) });
}
/**
* This method gets a single WebPage from the database, using the ID field
* as a key
*
* @param id
* the ID of the WebPage we want
* @return a Warrior object
*/
public WebPage getWebPage(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_NAME, new String[] { _id + "", url,
source, date + "" }, _id + "=?",
new String[] { String.valueOf(id) }, null, null, null, null);
if (cursor != null) {
cursor.moveToFirst();
}
WebPage webPage = new WebPage(Integer.parseInt(null,
cursor.getInt(0)),
cursor.getString(1),
cursor.getString(2),
cursor.getInt(3));
db.close();
cursor.close();
return webPage;
}
public WebPage getWebPageByName(String name){
String selectQuery = "SELECT * FROM " + TABLE_NAME + " WHERE " + _id + " = '" + name + "'";
Log.d("Debug WebPage name: ", selectQuery);
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
WebPage webPage = null;
if(cursor.moveToFirst()){
webPage = new WebPage(cursor.getInt(0),
cursor.getString(1),
cursor.getString(2),
cursor.getInt(3));
}
db.close();
cursor.close();
return webPage;
}
}
当我运行它时，我得到了这个：
01-05 17:24:19.594: E/Database(1524): Failure 1 (near "0": syntax error) on 0x2465e0 when preparing 'CREATE TABLE pages(0 INTEGER PRIMARY KEY,url URL,source Source, 0 Date)'.
01-05 17:24:19.699: E/AndroidRuntime(1524): java.lang.RuntimeException: Unable to start activity ComponentInfo{uk.ac.tees.L1087591/uk.ac.tees.L1087591.Home}: android.database.sqlite.SQLiteException: near "0": syntax error: CREATE TABLE pages(0 INTEGER PRIMARY KEY,url URL,source Source, 0 Date)
01-05 17:24:19.699: E/AndroidRuntime(1524): Caused by: android.database.sqlite.SQLiteException: near "0": syntax error: CREATE TABLE pages(0 INTEGER PRIMARY KEY,url URL,source Source, 0 Date)
01-05 17:24:19.699: E/AndroidRuntime(1524): at android.database.sqlite.SQLiteDatabase.native_execSQL(Native Method)
01-05 17:24:19.699: E/AndroidRuntime(1524): at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1727)
01-05 17:24:19.699: E/AndroidRuntime(1524): at uk.ac.tees.L1087591.DatabaseHandler.onCreate(DatabaseHandler.java:76)
01-05 17:24:19.699: E/AndroidRuntime(1524): at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:106)
01-05 17:24:19.699: E/AndroidRuntime(1524): at uk.ac.tees.L1087591.DatabaseHandler.addWebPage(DatabaseHandler.java:101)
01-05 17:24:19.699: E/AndroidRuntime(1524): at uk.ac.tees.L1087591.Home.onCreate(Home.java:52)
01-05 17:24:19.699: E/AndroidRuntime(1524): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-05 17:24:19.699: E/AndroidRuntime(1524): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
01-05 17:24:19.699: E/AndroidRuntime(1524): ... 11 more
答案 0 :(得分：1)
您的代码中有static final int _id = 0;。你应该在这里提供一个字符串。您可以自己跟踪它：SQL查询无效，0不应该存在。
我建议用
替换该行static final String _id = "id";
可能还有其他错误，请尝试自行查找。
答案 1 :(得分：1)
更改
static final int _id = 0;
static final int date = 0;
到
static final int _id = "id";
static final int date = "date";
因为表列名总是创建为String而不是Integer
答案 2 :(得分：1)
由SQL语句引起的错误：
CREATE TABLE页面（0 INTEGER PRIMARY KEY，url URL，source Source，0 日期）
你不能把0 INTEGER PRIMARY KEY，列名应该是有意义的东西。如果SQL语句是由java代码生成的，那么你应该检查是什么产生了0.
答案 3 :(得分：1)
您的创建查询（在DatabaseHandler :: onCreate（）中执行）无效：
'CREATE TABLE pages(0 INTEGER PRIMARY KEY,url URL,source Source, 0 Date)'
看起来应该是这样的：
'CREATE TABLE pages(id INTEGER PRIMARY KEY,url TEXT,source TEXT, INTEGER Date)'
您可以在此处找到SQLite Datatypes。