我正在尝试在Android中打开并写入sqlite数据库.根据日志输出,它没有打开.我知道我的语法不是很好,我应该从Party对象中保存而不是直接从片段接口中保存,但是我的重点实际上是过程.任何帮助都会超级有帮助!
package com.android.sqldatabase.sqldatabaseapp;
//imports deleted to save space
public class sqlDatabase {
public static final String KEY_ROWID = "_id";
public static final String KEY_NAME = "name";
public static final String KEY_PARTY = "party_date";
public static final String KEY_STATE = "state";
public static final String KEY_JDATE = "j_date";
public static final String KEY_JTITLE = "j_title";
public static final String KEY_JENTRY = "j_entry";
public static final String KEY_Jrating = "j_rating";
public static final String KEY_JENTRYEDITION = "j_entryEdition";
private static final String DATABASE_NAME = "PartyInfoDB";
private static final String DATABASE_READABLE = "readableinformation";
private static final String DATABASE_WRITEABLE = "writeableinformation";
private static final int DATABASE_VERSION = 20141;
private DbHelper mHelper;
private final Context mContext;
private sqliteDatabase mDatabase;
private static class DbHelper extends sqliteOpenHelper {
public DbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
//Set up database here
public void onCreate(sqliteDatabase db) {
db.execsql("CREATE TABLE " + DATABASE_READABLE + " (" +
//Column name Type of variable
KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_NAME + " TEXT NOT NULL, " +
KEY_PARTY + " TEXT NOT NULL, " +
KEY_STATE + " TEXT NOT NULL);"
db.execsql("CREATE TABLE " + DATABASE_WRITEABLE + " (" +
KEY_JENTRYEDITION + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_JDATE + " INTEGER NOT NULL, " +
KEY_JTITLE + " TEXT NOT NULL, " +
KEY_Jrating + " FLOAT NOT NULL, " +
KEY_JENTRY + " TEXT NOT NULL);"
);
}
@Override
public void onUpgrade(sqliteDatabase db, int oldVersion, int newVersion) {
db.execsql("DROP TABLE IF EXISTS " + DATABASE_READABLE);
db.execsql("DROP IF TABLE EXISTS " + DATABASE_WRITEABLE);
onCreate(db);
}
}
public sqlDatabase (Context c) {
mContext = c;
}
public sqlDatabase open() throws sqlException {
//Set up the helper with the context
mHelper = new DbHelper (mContext);
//Open the database with our helper
mDatabase = mHelper.getWritableDatabase();
return this;
}
mHelper.close();
}
public long createEntry(String title, String entry, float ratingBar,
String date) {
ContentValues cv = new ContentValues();
cv.put(KEY_JDATE, date);
cv.put(KEY_JTITLE, title);
cv.put(KEY_Jrating, ratingBar);
cv.put(KEY_JENTRY, date);
return mDatabase.insert(DATABASE_WRITEABLE, null, cv);
}
}
这是界面屏幕:
package com.android.sqldatabase.sqldatabaseapp;
//imports deleted to save space
public class LogFragment extends Fragment implements OnClickListener{
private String TAG;
private String TAG1;
private String mName;
EditText msqlTitle, msqlEntry;
Button mSaveButton;
ratingBar msqlratingBar;
private TextView msqlDate;
private Party mParty;
private Date mDate;
private Context mContext;
//Our onCreate method
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
//Inflate our fragment into the container
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle
savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_log, parent, false);
mDate = new Date();
msqlTitle = (EditText)v.findViewById(R.id.review_title);
msqlEntry = (EditText)v.findViewById(R.id.review_entry_textBox);
mSaveButton = (Button)v.findViewById(R.id.sqlsave_button);
mSaveButton.setonClickListener(this);
msqlratingBar = (ratingBar)v.findViewById(R.id.party_ratings_bar);
msqlDate = (TextView)v.findViewById(R.id.review_date);
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy", Locale.US);
String sdfString = sdf.format(mDate);
msqlDate.setText(sdfString);
return v;
}
//Our 2 buttons
public void onClick(View arg0) {
switch (arg0.getId()) {
case R.id.sqlsave_button:
boolean didItWork = true;
try {
//Convert our edit texts to strings
String title = msqlTitle.getText().toString();
String entry = msqlEntry.getText().toString();
float ratingBar = msqlratingBar.getrating();
String date = msqlDate.getText().toString();
//Write all of this to the database
sqlDatabase dbEntry = new sqlDatabase(this);
dbEntry.open();
Log.i(TAG1, "Database opened.");
dbEntry.createEntry(title, entry, ratingBar, date);
dbEntry.close();
} catch (Exception e) {
didItWork = false;
Log.e(TAG, "Database didn't upgrade when button pressed");
} finally {
if(didItWork) {
Toast toast = Toast.makeText(getActivity(),
R.string.save_toast, Toast.LENGTH_LONG);
toast.show();
}
}
break;
R.id.cancelButton
//INSET CANCEL BUTTON HERE
}
}
}
解决方法:
尝试这个
sqlDatabase dbEntry = new sqlDatabase(getActivity());
代替
sqlDatabase dbEntry = new sqlDatabase(this);