此代码将在正确的 TextView 中显示一个空白字符串，但是当我尝试显示我的数据库的内容时，我收到一个错误，任何人都可以看到我注释掉的代码有问题吗？
public String getData() {
String data = "";
String[] columns = new String[] {KEY_ROWID, KEY_EXERCISE, KEY_WEIGHT, KEY_SETS};
/*Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
int iRow = c.getColumnIndex(KEY_ROWID);
int iExercise = c.getColumnIndex(KEY_EXERCISE);
int iWeight = c.getColumnIndex(KEY_WEIGHT);
int iSets = c.getColumnIndex(KEY_SETS);
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
data = data + c.getString(iRow) + " " + c.getString(iExercise) + " " + c.getString(iWeight)
+ " " + c.getString(iSets) + "\n";
}*/
return data;
}
下面是处理 TextView 的类
public class TheView extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.theview);
TheHandler i = new TheHandler(this);
i.open();
String data = i.getData();
TextView tv = (TextView) findViewById(R.id.tvResults);
tv.setText(data);
}
}
如果需要，我可以提供更多代码完整的处理程序类
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class TheHandler {
public static final String KEY_ROWID = "_id";
public static final String KEY_EXERCISE = "theexercise";
public static final String KEY_WEIGHT = "theweight";
public static final String KEY_SETS = "thesets";
private static final String DATABASE_NAME = "TheHandledb";
private static final String DATABASE_TABLE = "TheHandleTable";
private static final int DATABASE_VERSION = 2;
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);
}
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CONTACTS_TABLE = "CREATE TABLE " + DATABASE_TABLE + "("
+ KEY_ROWID + " INTEGER PRIMARY KEY," + KEY_EXERCISE + " TEXT,"
+ KEY_WEIGHT + " TEXT" + KEY_SETS + " TEXT" + ")";
db.execSQL(CREATE_CONTACTS_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
// Create tables again
onCreate(db);
}
}
public TheHandler(Context c) {
ourContext = c;
}
public void open() {
ourHelper = new DbHelper(ourContext);
ourDatabase = ourHelper.getWritableDatabase();
// TODO Auto-generated method stub
}
public long createEntry(String theExercise, String theWeight, String theSets) {
ContentValues cv = new ContentValues();
cv.put(KEY_EXERCISE, theExercise);
cv.put(KEY_WEIGHT, theWeight);
cv.put(KEY_SETS, theSets);
return ourDatabase.insert(DATABASE_TABLE, null,cv);
}
public void close() {
ourHelper.close();
}
public String getData() {
String data = "";
String[] columns = new String[] {KEY_ROWID, KEY_EXERCISE, KEY_WEIGHT, KEY_SETS};
/*Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
int iRow = c.getColumnIndex(KEY_ROWID);
int iExercise = c.getColumnIndex(KEY_EXERCISE);
int iWeight = c.getColumnIndex(KEY_WEIGHT);
int iSets = c.getColumnIndex(KEY_SETS);
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
data = data + c.getString(iRow) + " " + c.getString(iExercise) + " " + c.getString(iWeight)
+ " " + c.getString(iSets) + "\n";
}*/
return data;
}
}
我的日志猫
03-26 12:19:43.988: I/Database(471): sqlite returned: error code = 1, msg = no such column: thesets
03-26 12:19:43.998: D/AndroidRuntime(471): Shutting down VM
03-26 12:19:43.998: W/dalvikvm(471): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-26 12:19:44.078: E/AndroidRuntime(471): FATAL EXCEPTION: main
03-26 12:19:44.078: E/AndroidRuntime(471): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.anothersql/com.example.anothersql.TheView}: android.database.sqlite.SQLiteException: no such column: thesets: , while compiling: SELECT _id, theexercise, theweight, thesets FROM TheHandleTable
03-26 12:19:44.078: E/AndroidRuntime(471): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.os.Handler.dispatchMessage(Handler.java:99)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.os.Looper.loop(Looper.java:123)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.app.ActivityThread.main(ActivityThread.java:4627)
03-26 12:19:44.078: E/AndroidRuntime(471): at java.lang.reflect.Method.invokeNative(Native Method)
03-26 12:19:44.078: E/AndroidRuntime(471): at java.lang.reflect.Method.invoke(Method.java:521)
03-26 12:19:44.078: E/AndroidRuntime(471): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-26 12:19:44.078: E/AndroidRuntime(471): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-26 12:19:44.078: E/AndroidRuntime(471): at dalvik.system.NativeStart.main(Native Method)
03-26 12:19:44.078: E/AndroidRuntime(471): Caused by: android.database.sqlite.SQLiteException: no such column: thesets: , while compiling: SELECT _id, theexercise, theweight, thesets FROM TheHandleTable
03-26 12:19:44.078: E/AndroidRuntime(471): at android.database.sqlite.SQLiteCompiledSql.native_compile(Native Method)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.database.sqlite.SQLiteCompiledSql.compile(SQLiteCompiledSql.java:91)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.database.sqlite.SQLiteCompiledSql.<init>(SQLiteCompiledSql.java:64)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:80)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:46)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:42)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1345)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1229)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1184)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1264)
03-26 12:19:44.078: E/AndroidRuntime(471): at com.example.anothersql.TheHandler.getData(TheHandler.java:77)
03-26 12:19:44.078: E/AndroidRuntime(471): at com.example.anothersql.TheView.onCreate(TheView.java:16)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
03-26 12:19:44.078: E/AndroidRuntime(471): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
03-26 12:19:44.078: E/AndroidRuntime(471): ... 11 more
03-26 12:19:47.530: I/Process(471): Sending signal. PID: 471 SIG: 9