我的 SQLite 数据库似乎可以正常输入条目，但我无法将它们拉回来查看它们，每次加载 Activity 时我的应用程序都会崩溃，更改数据库版本会引发 SQL 异常并强制关闭应用程序。
下面是处理 SQL 的类:
package com.uhi.fatfighter;
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;
public class Stats {
public static final String KEY_ROWID = "_id";
public static final String KEY_WEIGHT = "weight";
public static final String KEY_WAIST = "waist";
public static final String KEY_CHEST = "chest";
public static final String KEY_LEGS = "legs";
public static final String KEY_ARMS = "arms";
private static final String DATABASE_NAME = "statsDB";
private static final String DATABASE_TABLE = "personalStats";
private static final int DATABASE_VERSION = 3;
private DbHelper ffHelper;
private final Context ffContext;
private SQLiteDatabase ffDatabase;
private static class DbHelper extends SQLiteOpenHelper {
public DbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" + KEY_ROWID
+ " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_WEIGHT
+ " TEXT NOT NULL, " + KEY_WAIST + " TEXT NOT NULL, "
+ KEY_CHEST + " TEXT NOT NULL, " + KEY_LEGS
+ " TEXT NOT NULL, " + KEY_ARMS + " TEXT NOT NULL);");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXIST " + DATABASE_TABLE);
onCreate(db);
}
}
public Stats(Context c) {
ffContext = c;
}
public Stats open() throws SQLException {
ffHelper = new DbHelper(ffContext);
ffDatabase = ffHelper.getWritableDatabase();
return this;
}
public void close() {
ffHelper.close();
}
public long createEntry(String weight, String waist, String chest, String legs, String arms) {
ContentValues cv = new ContentValues();
cv.put(KEY_WEIGHT, weight);
cv.put(KEY_WAIST, waist);
cv.put(KEY_CHEST, chest);
cv.put(KEY_LEGS, legs);
cv.put(KEY_ARMS, arms);
return ffDatabase.insert(DATABASE_TABLE, null, cv);
}
public String getData() {
String[] columns = new String[] { KEY_ROWID, KEY_WEIGHT, KEY_WAIST, KEY_CHEST, KEY_LEGS, KEY_ARMS };
Cursor c = ffDatabase.query(DATABASE_TABLE, columns, null, null, null,
null, null);
String result = "";
int iRow = c.getColumnIndex(KEY_ROWID);
int iWeight = c.getColumnIndex(KEY_WEIGHT);
int iWaist = c.getColumnIndex(KEY_WAIST);
int iChest = c.getColumnIndex(KEY_CHEST);
int iLegs = c.getColumnIndex(KEY_LEGS);
int iArms = c.getColumnIndex(KEY_ARMS);
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
result = result + c.getString(iRow) + " " + c.getString(iWeight)
+ " " + c.getString(iWaist)
+ " " + c.getString(iChest)
+ " " + c.getString(iLegs)
+ " " + c.getString(iArms) + "\n";
}
return result;
}
}
下面是调用 SQL 处理类的 Activity:
package com.uhi.fatfighter;
import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.widget.TextView;
public class DBView extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.view_stats);
TextView tv = (TextView) findViewById(R.id.tvDBInfo);
Stats dbInfo = new Stats(this);
dbInfo.open();
String data = dbInfo.getData();
dbInfo.close();
if (!TextUtils.isEmpty(data)) {
tv.setText(data);
}
}
}
正如我所说，在我添加一些额外的字段之前，这工作正常
日志猫:
05-09 13:44:32.761: E/Trace(7576): error opening trace file: No such file or directory (2)
05-09 13:44:32.894: E/InputDispatcher(1294): channel '415d5068 com.uhi.fatfighter/com.uhi.fatfighter.Splash (server)' ~ Channel is unrecoverably broken and will be disposed!
05-09 13:44:34.964: E/Trace(7593): error opening trace file: No such file or directory (2)
05-09 13:44:34.988: E/Trace(7598): error opening trace file: No such file or directory (2)
05-09 13:44:54.250: E/AndroidRuntime(7598): FATAL EXCEPTION: main
05-09 13:44:54.250: E/AndroidRuntime(7598): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.uhi.fatfighter/com.uhi.fatfighter.DBView}: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.view.ViewGroup
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2185)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2210)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.app.ActivityThread.access$600(ActivityThread.java:142)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1208)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.os.Handler.dispatchMessage(Handler.java:99)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.os.Looper.loop(Looper.java:137)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.app.ActivityThread.main(ActivityThread.java:4928)
05-09 13:44:54.250: E/AndroidRuntime(7598): at java.lang.reflect.Method.invokeNative(Native Method)
05-09 13:44:54.250: E/AndroidRuntime(7598): at java.lang.reflect.Method.invoke(Method.java:511)
05-09 13:44:54.250: E/AndroidRuntime(7598): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
05-09 13:44:54.250: E/AndroidRuntime(7598): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:558)
05-09 13:44:54.250: E/AndroidRuntime(7598): at dalvik.system.NativeStart.main(Native Method)
05-09 13:44:54.250: E/AndroidRuntime(7598): Caused by: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.view.ViewGroup
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.view.LayoutInflater.rInflate(LayoutInflater.java:747)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
05-09 13:44:54.250: E/AndroidRuntime(7598): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:256)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.app.Activity.setContentView(Activity.java:1867)
05-09 13:44:54.250: E/AndroidRuntime(7598): at com.uhi.fatfighter.DBView.onCreate(DBView.java:16)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.app.Activity.performCreate(Activity.java:5008)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
05-09 13:44:54.250: E/AndroidRuntime(7598): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2139)
05-09 13:44:54.250: E/AndroidRuntime(7598): ... 11 more
05-09 13:44:56.765: E/Trace(7630): error opening trace file: No such file or directory (2)
05-09 13:45:10.125: E/Trace(7649): error opening trace file: No such file or directory (2)
05-09 13:45:10.433: E/Trace(7664): error opening trace file: No such file or directory (2)
05-09 13:45:11.183: E/Trace(7678): error opening trace file: No such file or directory (2)
05-09 13:45:12.203: E/Trace(7695): error opening trace file: No such file or directory (2)
05-09 13:45:14.187: E/AndroidRuntime(7630): FATAL EXCEPTION: main
05-09 13:45:14.187: E/AndroidRuntime(7630): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.uhi.fatfighter/com.uhi.fatfighter.DBView}: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.view.ViewGroup
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2185)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2210)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.app.ActivityThread.access$600(ActivityThread.java:142)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1208)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.os.Handler.dispatchMessage(Handler.java:99)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.os.Looper.loop(Looper.java:137)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.app.ActivityThread.main(ActivityThread.java:4928)
05-09 13:45:14.187: E/AndroidRuntime(7630): at java.lang.reflect.Method.invokeNative(Native Method)
05-09 13:45:14.187: E/AndroidRuntime(7630): at java.lang.reflect.Method.invoke(Method.java:511)
05-09 13:45:14.187: E/AndroidRuntime(7630): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
05-09 13:45:14.187: E/AndroidRuntime(7630): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:558)
05-09 13:45:14.187: E/AndroidRuntime(7630): at dalvik.system.NativeStart.main(Native Method)
05-09 13:45:14.187: E/AndroidRuntime(7630): Caused by: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.view.ViewGroup
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.view.LayoutInflater.rInflate(LayoutInflater.java:747)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
05-09 13:45:14.187: E/AndroidRuntime(7630): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:256)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.app.Activity.setContentView(Activity.java:1867)
05-09 13:45:14.187: E/AndroidRuntime(7630): at com.uhi.fatfighter.DBView.onCreate(DBView.java:16)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.app.Activity.performCreate(Activity.java:5008)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
05-09 13:45:14.187: E/AndroidRuntime(7630): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2139)
05-09 13:45:14.187: E/AndroidRuntime(7630): ... 11 more
05-09 13:45:18.433: E/Trace(7722): error opening trace file: No such file or directory (2)
05-09 13:52:02.109: E/Trace(7767): error opening trace file: No such file or directory (2)
05-09 13:52:03.554: E/Trace(7781): error opening trace file: No such file or directory (2)
05-09 13:55:06.617: E/Trace(7807): error opening trace file: No such file or directory (2)
05-09 13:55:26.808: E/AndroidRuntime(7807): FATAL EXCEPTION: main
05-09 13:55:26.808: E/AndroidRuntime(7807): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.uhi.fatfighter/com.uhi.fatfighter.DBView}: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.view.ViewGroup
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2185)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2210)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.app.ActivityThread.access$600(ActivityThread.java:142)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1208)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.os.Handler.dispatchMessage(Handler.java:99)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.os.Looper.loop(Looper.java:137)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.app.ActivityThread.main(ActivityThread.java:4928)
05-09 13:55:26.808: E/AndroidRuntime(7807): at java.lang.reflect.Method.invokeNative(Native Method)
05-09 13:55:26.808: E/AndroidRuntime(7807): at java.lang.reflect.Method.invoke(Method.java:511)
05-09 13:55:26.808: E/AndroidRuntime(7807): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
05-09 13:55:26.808: E/AndroidRuntime(7807): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:558)
05-09 13:55:26.808: E/AndroidRuntime(7807): at dalvik.system.NativeStart.main(Native Method)
05-09 13:55:26.808: E/AndroidRuntime(7807): Caused by: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.view.ViewGroup
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.view.LayoutInflater.rInflate(LayoutInflater.java:747)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
05-09 13:55:26.808: E/AndroidRuntime(7807): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:256)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.app.Activity.setContentView(Activity.java:1867)
05-09 13:55:26.808: E/AndroidRuntime(7807): at com.uhi.fatfighter.DBView.onCreate(DBView.java:16)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.app.Activity.performCreate(Activity.java:5008)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
05-09 13:55:26.808: E/AndroidRuntime(7807): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2139)
05-09 13:55:26.808: E/AndroidRuntime(7807): ... 11 more
05-09 13:58:40.242: E/Trace(7828): error opening trace file: No such file or directory (2)
05-09 13:58:40.500: E/Trace(7841): error opening trace file: No such file or directory (2)
05-09 13:58:40.937: E/PhotoDatabaseHelper(7828): query fail: empty cursor: android.database.sqlite.SQLiteCursor@415ae7e8
05-09 13:58:40.937: E/WidgetProvider(7828): cannot load widget: 5
我可以看到该类在转换 TextView 时遇到问题
最佳答案
DROP TABLE IF EXISTS
是正确的语法。
关于java - Android SQLite数据库版本，更改结构现在无法查看DB，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16461543/