我正在尝试使用this教程创建数据库。我在android开发方面还是新手，所以这可能很容易，但仍在学习。这是我得到的错误：
07-19 14:37:18.235: E/SQLiteLog(9089): (1) no such table: grocery
07-19 14:37:18.245: E/AndroidRuntime(9089): FATAL EXCEPTION: main
07-19 14:37:18.245: E/AndroidRuntime(9089): Process: com.dusandimitrijevic.grocerylist, PID: 9089
07-19 14:37:18.245: E/AndroidRuntime(9089): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.dusandimitrijevic.grocerylist/com.dusandimitrijevic.grocerylist.MainActivity}: android.database.sqlite.SQLiteException: no such table: grocery (code 1): , while compiling: SELECT _id, title, price FROM grocery
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2693)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2758)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.app.ActivityThread.access$900(ActivityThread.java:177)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1448)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.os.Handler.dispatchMessage(Handler.java:102)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.os.Looper.loop(Looper.java:145)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.app.ActivityThread.main(ActivityThread.java:5942)
07-19 14:37:18.245: E/AndroidRuntime(9089): at java.lang.reflect.Method.invoke(Native Method)
07-19 14:37:18.245: E/AndroidRuntime(9089): at java.lang.reflect.Method.invoke(Method.java:372)
07-19 14:37:18.245: E/AndroidRuntime(9089): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
07-19 14:37:18.245: E/AndroidRuntime(9089): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)
07-19 14:37:18.245: E/AndroidRuntime(9089): Caused by: android.database.sqlite.SQLiteException: no such table: grocery (code 1): , while compiling: SELECT _id, title, price FROM grocery
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:1093)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:670)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:59)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1440)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1287)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1158)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1326)
07-19 14:37:18.245: E/AndroidRuntime(9089): at com.dusandimitrijevic.data.GroceryDbAdapter.fetchAllItems(GroceryDbAdapter.java:145)
07-19 14:37:18.245: E/AndroidRuntime(9089): at com.dusandimitrijevic.grocerylist.MainActivity.fillData(MainActivity.java:79)
07-19 14:37:18.245: E/AndroidRuntime(9089): at com.dusandimitrijevic.grocerylist.MainActivity.onCreate(MainActivity.java:59)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.app.Activity.performCreate(Activity.java:6289)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
07-19 14:37:18.245: E/AndroidRuntime(9089): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
07-19 14:37:18.245: E/AndroidRuntime(9089): ... 10 more
以下是数据库的代码：
package com.dusandimitrijevic.data;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
/**
* Simple notes database access helper class. Defines the basic CRUD operations
* for the notepad example, and gives the ability to list all notes as well as
* retrieve or modify a specific note.
*
* This has been improved from the first version of this tutorial through the
* addition of better error handling and also using returning a Cursor instead
* of using a collection of inner classes (which is less scalable and not
* recommended).
*/
public class GroceryDbAdapter {
public static final String KEY_TITLE = "title";
public static final String KEY_PRICE = "price";
public static final String KEY_ROWID = "_id";
private static final String TAG = "GroceryDbAdapter";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
private Context mCtx;
/**
* Database creation sql statement
*/
private static final String DATABASE_CREATE =
"create table grocery (_id integer primary key autoincrement, "
+ "title text not null, price text not null);";
private static final String DATABASE_NAME = "data";
private static final String DATABASE_TABLE = "grocery";
private static final int DATABASE_VERSION = 2;
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS notes");
onCreate(db);
}
}
/**
* Constructor - takes the context to allow the database to be
* opened/created
*
* @param ctx the Context within which to work
*/
public GroceryDbAdapter(Context ctx) {
this.mCtx = ctx;
}
/**
* Open the notes database. If it cannot be opened, try to create a new
* instance of the database. If it cannot be created, throw an exception to
* signal the failure
*
* @return this (self reference, allowing this to be chained in an
* initialization call)
* @throws SQLException if the database could be neither opened or created
*/
public GroceryDbAdapter open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
mDbHelper.close();
}
/**
* Create a new note using the title and body provided. If the note is
* successfully created return the new rowId for that note, otherwise return
* a -1 to indicate failure.
*
* @param title the title of the note
* @param body the body of the note
* @return rowId or -1 if failed
*/
public long createItem(String title, String price) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_TITLE, title);
initialValues.put(KEY_PRICE, price);
return mDb.insert(DATABASE_TABLE, null, initialValues);
}
/**
* Delete the note with the given rowId
*
* @param rowId id of note to delete
* @return true if deleted, false otherwise
*/
public boolean deleteItem(long rowId) {
return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
/**
* Return a Cursor over the list of all notes in the database
*
* @return Cursor over all notes
*/
public Cursor fetchAllItems() {
return mDb.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_TITLE,
KEY_PRICE}, null, null, null, null, null);
}
/**
* Return a Cursor positioned at the note that matches the given rowId
*
* @param rowId id of note to retrieve
* @return Cursor positioned to matching note, if found
* @throws SQLException if note could not be found/retrieved
*/
public Cursor fetchItem(long rowId) throws SQLException {
Cursor mCursor =
mDb.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
KEY_TITLE, KEY_PRICE}, KEY_ROWID + "=" + rowId, null,
null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
/**
* Update the note using the details provided. The note to be updated is
* specified using the rowId, and it is altered to use the title and body
* values passed in
*
* @param rowId id of note to update
* @param title value to set note title to
* @param body value to set note body to
* @return true if the note was successfully updated, false otherwise
*/
public boolean updateItem(long rowId, String title, String price) {
ContentValues args = new ContentValues();
args.put(KEY_TITLE, title);
args.put(KEY_PRICE, price);
return mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
}
}
我还在学习，所以任何帮助或建议都会被高估。
答案 0 :(得分：2)
最有可能的是，您更改了 DATABASE_CREATE 字符串中定义的SQL语句，而不是更改数据库版本。
更改数据库版本，调用onUpgrade()并调用其中的SQL语句：
db.execSQL("DROP TABLE IF EXISTS notes");
这尝试删除表可能不存在。
然后调用onCreate()并尝试创建一个表，但由于它可能已经存在，所以没有任何反应，但您的表仍然是您在版本1中创建的表。
因此，解决方案可以是：
从您的设备取消安装应用程序并重新安装（将删除以前版本的数据库）
删除说明：
db.execSQL("DROP TABLE IF EXISTS notes");
并使用：
db.execSQL("DROP TABLE IF EXISTS grocery");
答案 1 :(得分：-1)
在您的DATABASE_CREATE查询中删除字符串中的分号它导致错误
private static final String DATABASE_CREATE =
"create table grocery (_id integer primary key autoincrement, "
+ "title text not null, price text not null)";//removed which was semicolon inside it