这是我的MainActivity文件。
package com.example.applicationmy;
import java.io.IOException;
import android.content.Intent;
import android.database.Cursor;
import android.database.SQLException;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity {
public final static String EXTRA_MESSAGE = "com.example.ApplicationMy.MESSAGE";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DataBaseHelper myDbHelper = new DataBaseHelper(this);
try {
// check if database exists in app path, if not copy it from assets
myDbHelper.create();
} catch (IOException ioe) {
throw new Error("Unable to create database");
}
try {
// open the database
myDbHelper.open();
myDbHelper.getWritableDatabase();
} catch (SQLException sqle) {
throw sqle;
}
Cursor c = myDbHelper.getUser(1);
Toast.makeText(this,
"id: " + c.getInt(0)+ "\n NO: " + c.getString(1)
+ "\n FROM: " + c.getString(2) + "\n TO: "
+ c.getString(3) + "\n VIA: "
+ c.getString(4) + "\n LENGTH "
+ c.getFloat(5), Toast.LENGTH_LONG).show();
c.close();
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void sendMessage(View view) {
// Do something in response to button
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.From);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
public void sendAnotherMessage(View view) {
// Do something in response to button
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.RouteNo);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
这是我从数据库中读取的DatabaseHelper类。
package com.example.applicationmy;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
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.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
public class DataBaseHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "route.sqlite";
private static final int DATABASE_VERSION = 1;
private static final String TABLE_NAME = "Routedet";
private static final String COLUMN_ID = "_id";
private static final String COLUMN_Route_no = "Route_no";
private static final String COLUMN_Route_location = "Route_location";
private static final String COLUMN_Route_dest = "Route_dest";
private static final String COLUMN_Route_via = "Route_via";
private static final String COLUMN_Route_len = "Route_len";
private SQLiteDatabase database;
private final Context context;
// database path
private static String DATABASE_PATH;
/** construcRoute_destr */
public DataBaseHelper(Context ctx) {
super(ctx, DATABASE_NAME, null, DATABASE_VERSION);
this.context = ctx;
DATABASE_PATH = context.getFilesDir().getParentFile().getPath()
+ "/databases/";
}
/**
* Creates a empty database on the system and rewrites it with your own
* database.
* */
public void create() throws IOException {
boolean check = checkDataBase();
SQLiteDatabase db_Read = null;
// Creates empty database default system path
db_Read = this.getWritableDatabase();
db_Read.close();
try {
if (!check) {
copyDataBase();
}
} catch (IOException e) {
throw new Error("Error copying database");
}
}
/**
* Check if the database already exist Route_dest 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 {
String myPath = DATABASE_PATH + DATABASE_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READWRITE);
} catch (SQLiteException e) {
// database does't exist yet.
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database Route_location your local assets-folder Route_dest the just created
* empty database in the system folder, Route_location 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 = context.getAssets().open(DATABASE_NAME);
// Path Route_dest the just created empty db
String outFileName = DATABASE_PATH + DATABASE_NAME;
// Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// transfer bytes Route_location the inputfile Route_dest the outputfile
byte[] buffer = new byte[1024];
int Route_len;
while ((Route_len = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, Route_len);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
/** open the database */
public void open() throws SQLException {
String myPath = DATABASE_PATH + DATABASE_NAME;
database = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READWRITE);
}
/** close the database */
@Override
public synchronized void close() {
if (database != null)
database.close();
super.close();
}
// retrieves a particular user
public Cursor getUser(long rowId) throws SQLException {
Cursor mCursor = database.query(true, TABLE_NAME, new String[] {
COLUMN_ID, COLUMN_Route_no, COLUMN_Route_location, COLUMN_Route_dest, COLUMN_Route_via, COLUMN_Route_len},
COLUMN_ID + " = " + rowId, null, null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
// delete a particular user
public boolean deleteContact(long rowId) {
return database.delete(TABLE_NAME, COLUMN_ID + "=" + rowId, null) > 0;
}
// retrieves all users
public Cursor getAllUsers() {
return database.query(TABLE_NAME, new String[] { COLUMN_ID, COLUMN_Route_no, COLUMN_Route_location, COLUMN_Route_dest, COLUMN_Route_via, COLUMN_Route_len }, null, null,
null, null, null);
}
@Override
public void onCreate(SQLiteDatabase arg0) {
// Route_destDO AuRoute_dest-generated method stub
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Route_destDO AuRoute_dest-generated method stub
}
}
这里是logcat输出。请尽快帮助我。我被困在这一天超过一天。我明天要提交我的项目。请帮忙
04-27 12:27:33.339: E/SQLiteLog(2384): (1) no such column: Route_no
04-27 12:27:33.349: D/AndroidRuntime(2384): Shutting down VM
04-27 12:27:33.349: W/dalvikvm(2384): threadid=1: thread exiting with uncaught exception (group=0xb2a17ba8)
04-27 12:27:33.369: E/AndroidRuntime(2384): FATAL EXCEPTION: main
04-27 12:27:33.369: E/AndroidRuntime(2384): Process: com.example.applicationmy, PID: 2384
04-27 12:27:33.369: E/AndroidRuntime(2384): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.applicationmy/com.example.applicationmy.MainActivity}: android.database.sqlite.SQLiteException: no such column: Route_no (code 1): , while compiling: SELECT DISTINCT _id, Route_no, Route_location, Route_dest, Route_via, Route_len FROM Routedet WHERE _id = 1
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.os.Handler.dispatchMessage(Handler.java:102)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.os.Looper.loop(Looper.java:136)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-27 12:27:33.369: E/AndroidRuntime(2384): at java.lang.reflect.Method.invokeNative(Native Method)
04-27 12:27:33.369: E/AndroidRuntime(2384): at java.lang.reflect.Method.invoke(Method.java:515)
04-27 12:27:33.369: E/AndroidRuntime(2384): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-27 12:27:33.369: E/AndroidRuntime(2384): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-27 12:27:33.369: E/AndroidRuntime(2384): at dalvik.system.NativeStart.main(Native Method)
04-27 12:27:33.369: E/AndroidRuntime(2384): Caused by: android.database.sqlite.SQLiteException: no such column: Route_no (code 1): , while compiling: SELECT DISTINCT _id, Route_no, Route_location, Route_dest, Route_via, Route_len FROM Routedet WHERE _id = 1
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:500)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1161)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1032)
04-27 12:27:33.369: E/AndroidRuntime(2384): at com.example.applicationmy.DataBaseHelper.getUser(DataBaseHelper.java:138)
04-27 12:27:33.369: E/AndroidRuntime(2384): at com.example.applicationmy.MainActivity.onCreate(MainActivity.java:44)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.app.Activity.performCreate(Activity.java:5231)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-27 12:27:33.369: E/AndroidRuntime(2384): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
04-27 12:27:33.369: E/AndroidRuntime(2384): ... 11 more
04-27 12:27:37.759: I/Process(2384): Sending signal. PID: 2384 SIG: 9
答案 0 :(得分：1)
那是因为你的表不包含有问题的列。 （Route_no）。
可能的原因是您的create table语句错过了列定义，或者如果您在数据库的其余部分之后添加了该列，那么您没有增加数据库版本以使其更新架构。
修改：如果您使用null替换投影参数，然后打印出您使用的内容
Log.d(TAG, DatabaseUtils.dumpCursortToString(c));
它可以帮助您调试问题