我使用eclipse创建了一个android应用程序。我用一个按钮来存储一些信息，另一个用来从数据库中检索信息。第一个是工作，但当我按下VIEW按钮显示数据时，它显示“不幸的是MyDatabase已经停止”。我正在给你所有的信息。 主类SqlLiteExample.java：
public class SqlLiteExample extends Activity implements OnClickListener {
Button sqlUpdate, sqlView;
EditText etName,etAge,etContact;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.sqlliteexample);
sqlUpdate = (Button) findViewById(R.id.savebutton);
etName = (EditText) findViewById(R.id.editName);
etAge = (EditText) findViewById(R.id.editAge);
etContact = (EditText) findViewById(R.id.editContact);
sqlView = (Button) findViewById(R.id.viewbutton);
sqlView.setOnClickListener(this);
sqlUpdate.setOnClickListener(this);
}
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
switch(arg0.getId()){
case R.id.savebutton:
boolean didWork = true;
try{
String name = etName.getText().toString();
String age = etAge.getText().toString();
String contact = etContact.getText().toString();
MyDB entry = new MyDB(SqlLiteExample.this);
entry.open();
entry.createEntry(name,age,contact);
entry.close();
}catch(Exception e){
didWork = false;
String error = e.toString();
Dialog d = new Dialog(this);
d.setTitle("Error");
TextView tv = new TextView(this);
tv.setText(error);
d.setContentView(tv);
d.show();
}finally{
if(didWork){
Dialog d = new Dialog(this);
d.setTitle("Updated");
TextView tv = new TextView(this);
tv.setText("Success");
d.setContentView(tv);
d.show();
}
}
break;
case R.id.viewbutton:
Intent i = new Intent("com.bysakiralam.mydatabase.DISPLAYRECORDS");
startActivity(i);
break;
}
}
}
为了控制数据库，我使用了MyDB.java：
public class MyDB {
public static final String KEY_ROWID = "_id";
public static final String KEY_NAME = "persons_name";
public static final String KEY_AGE = "persons_age";
public static final String KEY_CONTACT = "persons_contact";
private static final String DATABASE_NAME = "MyDatabase";
private static final String DATABASE_TABLE = "peopleTable";
private static final int DATABASE_VERSION = 1;
private DbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourDatabase;
private static class DbHelper extends SQLiteOpenHelper{
public DbHelper(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_NAME + " TEXT NOT NULL, " +
KEY_AGE + "TEXT NOT NULL, " +
KEY_CONTACT + "TEXT NOT NULL);"
);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
onCreate(db);
}
}
public MyDB(Context c){
ourContext = c;
}
public MyDB open() throws SQLException{
ourHelper = new DbHelper(ourContext);
ourDatabase = ourHelper.getWritableDatabase();
return this;
}
public void close(){
ourHelper.close();
}
public long createEntry(String name, String age, String contact) {
// TODO Auto-generated method stub
ContentValues cv = new ContentValues();
cv.put(KEY_NAME, name);
cv.put(KEY_AGE, age);
cv.put(KEY_CONTACT, contact);
return ourDatabase.insert(DATABASE_TABLE, null, cv);
}
public String getData() {
// TODO Auto-generated method stub
String[] columns = new String[]{KEY_ROWID, KEY_NAME, KEY_AGE, KEY_CONTACT};
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
String result = "";
int iRow = c.getColumnIndex(KEY_ROWID);
int iName = c.getColumnIndex(KEY_NAME);
int iAGE = c.getColumnIndex(KEY_AGE);
int iCONTACT = c.getColumnIndex(KEY_CONTACT);
for(c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
result = result + c.getString(iRow) + " " + c.getString(iName) + " " + c.getString(iAGE) + " " + c.getString(iCONTACT) +"\n";
}
return result;
}
}
显示信息的另一个活动是DisplayRecords.java：
public class DisplayRecords extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.sqlview);
TextView tv = (TextView) findViewById(R.id.tvSQLinfo);
MyDB info = new MyDB(this);
try {
info.open();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String data = info.getData();
info.close();
tv.setText(data);
}
}
Main xml文件是sqlliteexample.xml：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/textName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/name"
android:textAppearance="?android:attr/textAppearanceSmall" />
<EditText
android:id="@+id/editName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:inputType="textPersonName" >
<requestFocus />
</EditText>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/textAge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/age" >
</TextView>
<EditText
android:id="@+id/editAge"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:inputType="number" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/textContcat"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/contact" />
<EditText
android:id="@+id/editContact"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:inputType="textMultiLine" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<Button
android:id="@+id/savebutton"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="@string/save"/>"
<Button
android:id="@+id/viewbutton"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/view" />
</LinearLayout>
要显示的另一个布局... sqlview.xml：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TableLayout
android:id="@+id/tableLayout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<TableRow>
<TextView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="0.5"
android:text="Names" >
</TextView>
<TextView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="0.5"
android:text="@string/age" >
</TextView>
<TextView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="0.5"
android:text="@string/contacts" >
</TextView>
</TableRow>
</TableLayout>
<TextView
android:id="@+id/tvSQLinfo"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="0.5"
android:text="@string/gt" >
</TextView>
manifest.xml是：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.bysakiralam.mydatabase"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="14" />
<compatible-screens></compatible-screens>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_USER_DICTIONARY"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.bysakiralam.mydatabase.SqlLiteExample"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".DisplayRecords" android:label="@string/app_name" >
<intent-filter>
<action android:name="com.bysakiralam.mydatabase.DISPLAYRECORDS" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>
我的错误在哪里？请帮助。 LogCat文件的内容：
07-11 16:46:11.312: E/Trace(668): error opening trace file: No such file or directory (2)
07-11 16:46:15.531: D/gralloc_goldfish(668): Emulator without GPU emulation detected.
07-11 16:46:32.695: I/Choreographer(668): Skipped 47 frames! The application may be doing too much work on its main thread.
07-11 12:26:37.454: I/Choreographer(668): Skipped 37 frames! The application may be doing too much work on its main thread.
07-11 12:26:40.614: I/Choreographer(668): Skipped 31 frames! The application may be doing too much work on its main thread.
07-11 12:26:43.694: D/dalvikvm(668): GC_CONCURRENT freed 81K, 8% free 2688K/2892K, paused 73ms+10ms, total 235ms
07-11 12:26:46.934: E/SQLiteLog(668): (1) table peopleTable has no column named persons_contact
07-11 12:26:46.984: E/SQLiteDatabase(668): Error inserting persons_contact=wert persons_age=32 persons_name=sad
07-11 12:26:46.984: E/SQLiteDatabase(668): android.database.sqlite.SQLiteException: table peopleTable has no column named persons_contact (code 1): , while compiling: INSERT INTO peopleTable(persons_contact,persons_age,persons_name) VALUES (?,?,?)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:882)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:493)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1467)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1339)
07-11 12:26:46.984: E/SQLiteDatabase(668): at com.bysakiralam.mydatabase.MyDB.createEntry(MyDB.java:68)
07-11 12:26:46.984: E/SQLiteDatabase(668): at com.bysakiralam.mydatabase.SqlLiteExample.onClick(SqlLiteExample.java:46)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.view.View.performClick(View.java:4204)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.view.View$PerformClick.run(View.java:17355)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.os.Handler.handleCallback(Handler.java:725)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.os.Handler.dispatchMessage(Handler.java:92)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.os.Looper.loop(Looper.java:137)
07-11 12:26:46.984: E/SQLiteDatabase(668): at android.app.ActivityThread.main(ActivityThread.java:5041)
07-11 12:26:46.984: E/SQLiteDatabase(668): at java.lang.reflect.Method.invokeNative(Native Method)
07-11 12:26:46.984: E/SQLiteDatabase(668): at java.lang.reflect.Method.invoke(Method.java:511)
07-11 12:26:46.984: E/SQLiteDatabase(668): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
07-11 12:26:46.984: E/SQLiteDatabase(668): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
07-11 12:26:46.984: E/SQLiteDatabase(668): at dalvik.system.NativeStart.main(Native Method)
07-11 12:26:54.745: I/Choreographer(668): Skipped 55 frames! The application may be doing too much work on its main thread.
07-11 12:26:56.694: E/SQLiteLog(668): (1) no such column: persons_age
07-11 12:26:56.745: D/AndroidRuntime(668): Shutting down VM
07-11 12:26:56.745: W/dalvikvm(668): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
07-11 12:26:56.934: E/AndroidRuntime(668): FATAL EXCEPTION: main
07-11 12:26:56.934: E/AndroidRuntime(668): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.bysakiralam.mydatabase/com.bysakiralam.mydatabase.DisplayRecords}: android.database.sqlite.SQLiteException: no such column: persons_age (code 1): , while compiling: SELECT _id, persons_name, persons_age, persons_contact FROM peopleTable
07-11 12:26:56.934: E/AndroidRuntime(668): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.app.ActivityThread.access$600(ActivityThread.java:141)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.os.Handler.dispatchMessage(Handler.java:99)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.os.Looper.loop(Looper.java:137)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.app.ActivityThread.main(ActivityThread.java:5041)
07-11 12:26:56.934: E/AndroidRuntime(668): at java.lang.reflect.Method.invokeNative(Native Method)
07-11 12:26:56.934: E/AndroidRuntime(668): at java.lang.reflect.Method.invoke(Method.java:511)
07-11 12:26:56.934: E/AndroidRuntime(668): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
07-11 12:26:56.934: E/AndroidRuntime(668): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
07-11 12:26:56.934: E/AndroidRuntime(668): at dalvik.system.NativeStart.main(Native Method)
07-11 12:26:56.934: E/AndroidRuntime(668): Caused by: android.database.sqlite.SQLiteException: no such column: persons_age (code 1): , while compiling: SELECT _id, persons_name, persons_age, persons_contact FROM peopleTable
07-11 12:26:56.934: E/AndroidRuntime(668): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:882)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:493)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1161)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1032)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1200)
07-11 12:26:56.934: E/AndroidRuntime(668): at com.bysakiralam.mydatabase.MyDB.getData(MyDB.java:73)
07-11 12:26:56.934: E/AndroidRuntime(668): at com.bysakiralam.mydatabase.DisplayRecords.onCreate(DisplayRecords.java:25)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.app.Activity.performCreate(Activity.java:5104)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
07-11 12:26:56.934: E/AndroidRuntime(668): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
07-11 12:26:56.934: E/AndroidRuntime(668): ... 11 more
07-11 12:27:01.954: I/Process(668): Sending signal. PID: 668 SIG: 9
答案 0 :(得分：1)
您应该在运行应用程序时检查日志cat，它将通知您出现错误的位置和位置。这会让你很好地了解出了什么问题。
答案 1 :(得分：0)
更改
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_NAME + " TEXT NOT NULL, " +
KEY_AGE + "TEXT NOT NULL, " +
KEY_CONTACT + "TEXT NOT NULL);"
);
到
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_NAME + " TEXT NOT NULL, " +
KEY_AGE + " TEXT NOT NULL, " +
KEY_CONTACT + " TEXT NOT NULL);"
);
原因：您没有在以下方面留出空间：
KEY_AGE + " TEXT NOT NULL, " + KEY_CONTACT + " TEXT NOT NULL);"
答案 2 :(得分：-1)
改变
db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_NAME + " TEXT NOT NULL, " +
KEY_AGE + " TEXT NOT NULL, " +
**KEY_CONTACT + " TEXT NOT NULL);"**
);
要
db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_NAME + " TEXT NOT NULL, " +
KEY_AGE + " TEXT NOT NULL, " +
**KEY_CONTACT + " TEXT NOT NULL)"
);**
您的语法错误很小