android从数据库类中传递变量
我试图传递一些从数据库内部（ extends sqliteOpenHelper ）到另一个类的值。 但是我使用游标从该数据库获取数据，该数据为其他活动提供空值。
这是我的数据库：它里面有默认值，插入
public class DatabaseMaster extends SQLiteOpenHelper { SQLiteDatabase db; private static final String LOG = "DatabaseHelper"; // Database Version private static final int DATABASE_VERSION = 1; // Database Name private static final String DATABASE_NAME = "Rates"; // Table Names public static final String KEY_ER_ID = "er_id"; public static final String KEY_ER_USEDORNEW = "Used_or_New"; public static final String KEY_ER_TENOR = "ER_tenor"; public static final String KEY_ER_RATE = "ER_rate"; // Asuransi rate public static final String KEY_AS_ID = "as_id"; public static final String KEY_AS_REGIONAL = "regional"; public static final String KEY_AS_TENOR = "AS_tenor"; public static final String KEY_AS_TLO = "TLO"; public static final String KEY_AS_COMPREHENSIVE = "Comprehensive"; public static final String KEY_AS_COMBINE = "Combine"; public static final String TABLE_EFFECTIVE_RATE = "effective_rate"; public static final String TABLE_ASURANSI_RATE = "asuransi_rate"; public DatabaseMaster(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 try { db.beginTransaction(); db.execSQL("CREATE TABLE " + TABLE_EFFECTIVE_RATE + " (" + KEY_ER_ID + " INTEGER PRIMARY KEY, " + KEY_ER_USEDORNEW + " TEXT NOT NULL, " + KEY_ER_TENOR + " INTEGER," + KEY_ER_RATE + " REAL)"); db.execSQL("CREATE TABLE " + TABLE_ASURANSI_RATE + " (" + KEY_AS_ID + " INTEGER PRIMARY KEY, " + KEY_AS_REGIONAL + " INTEGER, " + KEY_AS_TENOR + " INTEGER," + KEY_AS_TLO + " REAL," + KEY_AS_COMPREHENSIVE + " REAL," + KEY_AS_COMBINE + " REAL)"); // Inserts pre-defined departments InsertERs(db); insertASs(db); db.setTransactionSuccessful(); } finally { db.endTransaction(); } } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub db.execSQL("DROP TABLE IF EXISTS " + TABLE_EFFECTIVE_RATE); db.execSQL("DROP TABLE IF EXISTS " + TABLE_ASURANSI_RATE); // db.execSQL("DROP TRIGGER IF EXISTS er_id_trigger"); // db.execSQL("DROP TRIGGER IF EXISTS er_id_trigger22"); // db.execSQL("DROP TRIGGER IF EXISTS as_id_trigger"); // db.execSQL("DROP TRIGGER IF EXISTS as_id_trigger22"); onCreate(db); } void AddERrate(EntryEffectiveRate EER) { SQLiteDatabase db = this.getWritableDatabase(); ContentValues valuesER = new ContentValues(); valuesER.put(KEY_ER_ID, EER.getERId()); valuesER.put(KEY_ER_USEDORNEW, EER.getERKondisi()); valuesER.put(KEY_ER_TENOR, EER.getERTenor()); valuesER.put(KEY_ER_RATE, EER.getERrate()); // values.put(KEY_CREATED_AT, getDateTime()); // insert row // long er_id = db.insert(TABLE_EFFECTIVE_RATE, null, valuesER); // db.close(); // return er_id; } int getERCount() { SQLiteDatabase db = this.getWritableDatabase(); Cursor cur = db.rawQuery("Select * from " + TABLE_EFFECTIVE_RATE, null); int x = cur.getCount(); cur.close(); return x; } Cursor getAllERates() { SQLiteDatabase db = this.getWritableDatabase(); // Cursor cur= // db.rawQuery("Select "+colID+" as _id , "+colName+", "+colAge+" from "+employeeTable, // new String [] {}); // Cursor cur= db.rawQuery("SELECT * FROM "+viewEmps,null); Cursor cur = db.rawQuery("Select " + KEY_ER_ID + " as _id, " + KEY_ER_USEDORNEW + ", " + KEY_ER_TENOR + ", " + KEY_ER_RATE + ", " + " from " + TABLE_EFFECTIVE_RATE, new String[] {}); cur.close(); return cur; } public List getAllEffectiveRates() { List EffectiveRates = new ArrayList(); String selectQuery = "SELECT * FROM " + TABLE_EFFECTIVE_RATE; Log.e(LOG, selectQuery); SQLiteDatabase db = this.getReadableDatabase(); Cursor c = db.rawQuery(selectQuery, null); // looping through all rows and adding to list if (c.moveToFirst()) { do { EntryEffectiveRate ergt = new EntryEffectiveRate(); ergt.setERId(c.getInt(c.getColumnIndex(KEY_ER_ID))); ergt.setERKondisi(c.getString(c .getColumnIndex(KEY_ER_USEDORNEW))); ergt.setERTenor(c.getInt(c.getColumnIndex(KEY_ER_TENOR))); ergt.setERRate(c.getDouble(c.getColumnIndex(KEY_ER_RATE))); // add EffectiveRates.add(ergt); } while (c.moveToNext()); } // db.close(); c.close(); return EffectiveRates; } public int updateEntryEffectiveRate(EntryEffectiveRate er) { SQLiteDatabase db = this.getWritableDatabase(); ContentValues values = new ContentValues(); values.put(KEY_ER_ID, er.getERId()); values.put(KEY_ER_USEDORNEW, er.getERKondisi()); values.put(KEY_ER_TENOR, er.getERTenor()); values.put(KEY_ER_RATE, er.getERrate()); // values.put(KEY_CREATED_AT, getDateTime()); // updating row return db.update(TABLE_EFFECTIVE_RATE, values, KEY_ER_ID + " = ?", new String[] { String.valueOf(er.getERId()) }); } // public void deleteEntryEffectiveRate(long er_id) { SQLiteDatabase db = this.getWritableDatabase(); db.delete(TABLE_EFFECTIVE_RATE, KEY_ER_ID + " = ?", new String[] { String.valueOf(er_id) }); } void AddASrate(EntryAsuransiRate EAR) { SQLiteDatabase db = this.getWritableDatabase(); ContentValues valuesAS = new ContentValues(); valuesAS.put(KEY_AS_ID, EAR.getASId()); valuesAS.put(KEY_AS_REGIONAL, EAR.getASzona()); valuesAS.put(KEY_AS_TENOR, EAR.getAStenor()); valuesAS.put(KEY_AS_TLO, EAR.getAStlo()); valuesAS.put(KEY_AS_COMPREHENSIVE, EAR.getAScomp()); valuesAS.put(KEY_AS_COMBINE, EAR.getAScomb()); // values.put(KEY_CREATED_AT, getDateTime()); // insert row // long er_id = db.insert(TABLE_ASURANSI_RATE, null, valuesAS); // db.close(); // return er_id; } Cursor getAllASrates() { SQLiteDatabase db = this.getWritableDatabase(); Cursor cur = db.rawQuery("Select " + KEY_AS_ID + " as _id, " + KEY_AS_REGIONAL + ", " + KEY_AS_TENOR + ", " + KEY_AS_TLO + ", " + KEY_AS_COMPREHENSIVE + ", " + KEY_AS_COMBINE + ", " + " from " + TABLE_ASURANSI_RATE, new String[] {}); cur.close(); return cur; } int getASCount() { SQLiteDatabase db = this.getWritableDatabase(); Cursor cur = db.rawQuery("Select * from " + TABLE_ASURANSI_RATE, null); int x = cur.getCount(); cur.close(); return x; } public List getAllAsuransiRates() { List AsuransiRates = new ArrayList(); String selectQuery = "SELECT * FROM " + TABLE_ASURANSI_RATE; Log.e(LOG, selectQuery); SQLiteDatabase db = this.getReadableDatabase(); Cursor c = db.rawQuery(selectQuery, null); // looping through all rows and adding to list if (c.moveToFirst()) { do { EntryAsuransiRate asgt = new EntryAsuransiRate(); asgt.setASId(c.getInt(c.getColumnIndex(KEY_AS_ID))); asgt.setASzona(c.getInt(c.getColumnIndex(KEY_AS_REGIONAL))); asgt.setAStenor(c.getInt(c.getColumnIndex(KEY_AS_TENOR))); asgt.setAStlo(c.getDouble(c.getColumnIndex(KEY_AS_TLO))); asgt.setAScomp(c.getDouble(c .getColumnIndex(KEY_AS_COMPREHENSIVE))); asgt.setAScomb(c.getDouble(c.getColumnIndex(KEY_AS_COMBINE))); // add AsuransiRates.add(asgt); } while (c.moveToNext()); } // db.close(); c.close(); return AsuransiRates; } public int updateEntryAsuransiRate(EntryAsuransiRate EAR) { SQLiteDatabase db = this.getWritableDatabase(); ContentValues valuesAS = new ContentValues(); valuesAS.put(KEY_AS_ID, EAR.getASId()); valuesAS.put(KEY_AS_REGIONAL, EAR.getASzona()); valuesAS.put(KEY_AS_TENOR, EAR.getAStenor()); valuesAS.put(KEY_AS_TLO, EAR.getAStlo()); valuesAS.put(KEY_AS_COMPREHENSIVE, EAR.getAScomp()); valuesAS.put(KEY_AS_COMBINE, EAR.getAScomb()); // values.put(KEY_CREATED_AT, getDateTime()); // updating row return db.update(TABLE_ASURANSI_RATE, valuesAS, KEY_AS_ID + " = ?", new String[] { String.valueOf(EAR.getASId()) }); } // public void deleteEntryAsuransiRate(long as_id) { SQLiteDatabase db = this.getWritableDatabase(); db.delete(TABLE_ASURANSI_RATE, KEY_AS_ID + " = ?", new String[] { String.valueOf(as_id) }); } void InsertERs(SQLiteDatabase db) { try { db.beginTransaction(); ContentValues cv = new ContentValues(); cv.put(KEY_ER_ID, 1); cv.put(KEY_ER_USEDORNEW, "Baru"); cv.put(KEY_ER_TENOR, 12); cv.put(KEY_ER_RATE, 12.1); db.insert(TABLE_EFFECTIVE_RATE, KEY_ER_ID, cv); cv.put(KEY_ER_ID, 2); cv.put(KEY_ER_USEDORNEW, "Baru"); cv.put(KEY_ER_TENOR, 24); cv.put(KEY_ER_RATE, 12.2); db.insert(TABLE_EFFECTIVE_RATE, KEY_ER_ID, cv); cv.put(KEY_ER_ID, 3); cv.put(KEY_ER_USEDORNEW, "Baru"); cv.put(KEY_ER_TENOR, 36); cv.put(KEY_ER_RATE, 12.3); db.insert(TABLE_EFFECTIVE_RATE, KEY_ER_ID, cv); cv.put(KEY_ER_ID, 4); cv.put(KEY_ER_USEDORNEW, "Baru"); cv.put(KEY_ER_TENOR, 48); cv.put(KEY_ER_RATE, 12.4); db.insert(TABLE_EFFECTIVE_RATE, KEY_ER_ID, cv); cv.put(KEY_ER_ID, 5); cv.put(KEY_ER_USEDORNEW, "Baru"); cv.put(KEY_ER_TENOR, 60); cv.put(KEY_ER_RATE, 12.5); db.insert(TABLE_EFFECTIVE_RATE, KEY_ER_ID, cv); cv.put(KEY_ER_ID, 6); cv.put(KEY_ER_USEDORNEW, "Baru"); cv.put(KEY_ER_TENOR, 12); cv.put(KEY_ER_RATE, 12.6); db.insert(TABLE_EFFECTIVE_RATE, KEY_ER_ID, cv); cv.put(KEY_ER_ID, 7); cv.put(KEY_ER_USEDORNEW, "Baru"); cv.put(KEY_ER_TENOR, 24); cv.put(KEY_ER_RATE, 12.7); db.insert(TABLE_EFFECTIVE_RATE, KEY_ER_ID, cv); cv.put(KEY_ER_ID, 8); cv.put(KEY_ER_USEDORNEW, "Baru"); cv.put(KEY_ER_TENOR, 36); cv.put(KEY_ER_RATE, 12.8); db.insert(TABLE_EFFECTIVE_RATE, KEY_ER_ID, cv); cv.put(KEY_ER_ID, 9); cv.put(KEY_ER_USEDORNEW, "Baru"); cv.put(KEY_ER_TENOR, 48); cv.put(KEY_ER_RATE, 12.9); db.insert(TABLE_EFFECTIVE_RATE, KEY_ER_ID, cv); cv.put(KEY_ER_ID, 10); cv.put(KEY_ER_USEDORNEW, "Baru"); cv.put(KEY_ER_TENOR, 60); cv.put(KEY_ER_RATE, 13); db.insert(TABLE_EFFECTIVE_RATE, KEY_ER_ID, cv); // db.insert(TABLE_EFFECTIVE_RATE, KEY_ER_ID, cv); db.setTransactionSuccessful(); } finally { db.endTransaction(); } // db.close(); } void insertASs(SQLiteDatabase db) { try { db.beginTransaction(); ContentValues cv = new ContentValues(); cv.put(KEY_AS_ID, 1); cv.put(KEY_AS_REGIONAL, 1); cv.put(KEY_AS_TENOR, 12); cv.put(KEY_AS_TLO, 1.00); cv.put(KEY_AS_COMPREHENSIVE, 2.00); cv.put(KEY_AS_COMBINE, 3.00); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 2); cv.put(KEY_AS_REGIONAL, 1); cv.put(KEY_AS_TENOR, 24); cv.put(KEY_AS_TLO, 1.01); cv.put(KEY_AS_COMPREHENSIVE, 2.01); cv.put(KEY_AS_COMBINE, 3.01); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 3); cv.put(KEY_AS_REGIONAL, 1); cv.put(KEY_AS_TENOR, 36); cv.put(KEY_AS_TLO, 1.02); cv.put(KEY_AS_COMPREHENSIVE, 2.02); cv.put(KEY_AS_COMBINE, 3.02); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 4); cv.put(KEY_AS_REGIONAL, 1); cv.put(KEY_AS_TENOR, 48); cv.put(KEY_AS_TLO, 1.03); cv.put(KEY_AS_COMPREHENSIVE, 2.03); cv.put(KEY_AS_COMBINE, 3.03); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 5); cv.put(KEY_AS_REGIONAL, 1); cv.put(KEY_AS_TENOR, 60); cv.put(KEY_AS_TLO, 1.04); cv.put(KEY_AS_COMPREHENSIVE, 2.04); cv.put(KEY_AS_COMBINE, 3.04); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 6); cv.put(KEY_AS_REGIONAL, 2); cv.put(KEY_AS_TENOR, 12); cv.put(KEY_AS_TLO, 1.05); cv.put(KEY_AS_COMPREHENSIVE, 2.05); cv.put(KEY_AS_COMBINE, 3.05); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 7); cv.put(KEY_AS_REGIONAL, 2); cv.put(KEY_AS_TENOR, 24); cv.put(KEY_AS_TLO, 1.06); cv.put(KEY_AS_COMPREHENSIVE, 2.06); cv.put(KEY_AS_COMBINE, 3.06); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 8); cv.put(KEY_AS_REGIONAL, 2); cv.put(KEY_AS_TENOR, 36); cv.put(KEY_AS_TLO, 1.07); cv.put(KEY_AS_COMPREHENSIVE, 2.07); cv.put(KEY_AS_COMBINE, 3.07); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 9); cv.put(KEY_AS_REGIONAL, 2); cv.put(KEY_AS_TENOR, 48); cv.put(KEY_AS_TLO, 1.08); cv.put(KEY_AS_COMPREHENSIVE, 2.08); cv.put(KEY_AS_COMBINE, 3.08); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 10); cv.put(KEY_AS_REGIONAL, 2); cv.put(KEY_AS_TENOR, 60); cv.put(KEY_AS_TLO, 1.09); cv.put(KEY_AS_COMPREHENSIVE, 2.09); cv.put(KEY_AS_COMBINE, 3.09); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 11); cv.put(KEY_AS_REGIONAL, 3); cv.put(KEY_AS_TENOR, 12); cv.put(KEY_AS_TLO, 1.10); cv.put(KEY_AS_COMPREHENSIVE, 2.10); cv.put(KEY_AS_COMBINE, 3.10); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 12); cv.put(KEY_AS_REGIONAL, 3); cv.put(KEY_AS_TENOR, 24); cv.put(KEY_AS_TLO, 1.11); cv.put(KEY_AS_COMPREHENSIVE, 2.11); cv.put(KEY_AS_COMBINE, 3.11); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 13); cv.put(KEY_AS_REGIONAL, 3); cv.put(KEY_AS_TENOR, 36); cv.put(KEY_AS_TLO, 1.12); cv.put(KEY_AS_COMPREHENSIVE, 2.12); cv.put(KEY_AS_COMBINE, 3.12); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 14); cv.put(KEY_AS_REGIONAL, 3); cv.put(KEY_AS_TENOR, 48); cv.put(KEY_AS_TLO, 1.13); cv.put(KEY_AS_COMPREHENSIVE, 2.13); cv.put(KEY_AS_COMBINE, 3.13); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); cv.put(KEY_AS_ID, 15); cv.put(KEY_AS_REGIONAL, 3); cv.put(KEY_AS_TENOR, 60); cv.put(KEY_AS_TLO, 1.14); cv.put(KEY_AS_COMPREHENSIVE, 2.14); cv.put(KEY_AS_COMBINE, 3.14); db.insert(TABLE_ASURANSI_RATE, KEY_AS_ID, cv); db.setTransactionSuccessful(); } finally { db.endTransaction(); } // db1.close(); } public Cursor getERValues(int index) { String from[] = { "KEY_ER_USEDORNEW", "KEY_ER_TENOR", "KEY_ER_RATE" }; String where = DatabaseMaster.KEY_ER_ID + "=?"; String[] whereArgs = new String[] { index + "" }; Cursor cursor = db.query(DatabaseMaster.TABLE_EFFECTIVE_RATE, from, where, whereArgs, null, null, null, null); return cursor; } class DataHandler extends Activity { public void getData(int id) { Cursor c = getERValues(id); if (c != null) { while (c.moveToNext()) { String UorN = c.getString(c.getColumnIndex("Used_or_New")); int er_t = c.getInt(c.getColumnIndex("ER_tenor")); double er_r = c.getDouble(c.getColumnIndex("ER_rate")); // use these strings as you want Intent Person = new Intent(this, MediatorMaster.class); Person.putExtra("Used_or_New", UorN); Person.putExtra("ER_tenor", er_t); Person.putExtra("ER_rate", er_r); startActivity(Person); } } } } // closing database public void closeDB() { SQLiteDatabase db = this.getReadableDatabase(); if (db != null && db.isOpen()) db.close(); } @Override public void onOpen(SQLiteDatabase db) { super.onOpen(db); if (!db.isReadOnly()) { // Enable foreign key constraints db.execSQL("PRAGMA foreign_keys=ON;"); } } }
另一个假设显示通过intent发送的数据：
public class MediatorMaster extends Activity { @Override protected void onCreate(Bundle unpack) { // TODO Auto-generated method stub super.onCreate(unpack); setContentView(R.layout.test); unpack = getIntent().getExtras(); //for(){ if (unpack != null) { String UorN = unpack.getString("Used_or_New"); //int er_t = unpack.getInt("er_t"); //double er_r = unpack.getDouble("er_r"); Message.message(this, "Result :"+ UorN + " " /*+ er_t + " " + er_r*/); } else { Message.message(this, "unread datas"); } // } } }
编辑：我有另一个类，将显示多少条目，并将显示所有数据。 我创建了这个以确保数据是否真的存在。
将显示的类：
public class MainActivity extends Activity { // Database Helper DatabaseMaster db; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // SQLiteDatabase db = this.getReadaleDatabase(); //db = new DatabaseHelper(getApplicationContext()); db = new DatabaseMaster(getApplicationContext()); Log.d("Effectiverate Count", " EffectiverateCount: " + db.getASCount()); Log.d("Asuransirate Count", " AsuransirateCount: " + db.getERCount()); // getting all ER Log.d("Get ER", "GEtting All ER"); List allEffectiveRate = db.getAllEffectiveRates(); for (EntryEffectiveRate ER : allEffectiveRate) { Log.d("ER_ids", String.valueOf(ER.getERId())); Log.d("ER_rates", ER.getERKondisi()); Log.d("ER_tenors", String.valueOf(ER.getERTenor())); Log.d("ER_rates", String.valueOf(ER.getERrate())); } // getting all AS Log.d("Get AS", "GEtting All AS"); List allAsuransiRate = db.getAllAsuransiRates(); for (EntryAsuransiRate AS : allAsuransiRate) { Log.d("AS_ids", String.valueOf(AS.getASId())); Log.d("AS_tenors", String.valueOf(AS.getAStenor())); Log.d("AS_tlos", String.valueOf(AS.getAStlo())); Log.d("AS_comps", String.valueOf(AS.getAScomp())); Log.d("AS_combs", String.valueOf(AS.getAScomb())); } // Don't forget to close database connection db.closeDB(); }}
其他将成为构造函数的类，定义输入的参数：
public class EntryAsuransiRate { int as_id; int ASzona; int AStenor; double AStlo; double AScomp; double AScomb; // String created_at; // constructors public EntryAsuransiRate() { } public EntryAsuransiRate(int ASzona, int AStenor, double AStlo, double AScomp, double AScomb) { this.ASzona = ASzona; this.AStenor = AStenor; this.AStlo = AStlo; this.AScomp = AScomp; this.AScomb = AScomb; } public EntryAsuransiRate(int as_id, int ASzona, int AStenor, double AStlo, double AScomp, double AScomb) { this.as_id = as_id; this.ASzona = ASzona; this.AStenor = AStenor; this.AStlo = AStlo; this.AScomp = AScomp; this.AScomb = AScomb; } // setters public void setASId(int as_id) { this.as_id = as_id; } public void setASzona(int ASzona) { this.ASzona = ASzona; } public void setAStenor(int AStenor) { this.AStenor = AStenor; } public void setAStlo(double AStlo) { this.AStlo = AStlo; } public void setAScomp(double AScomp) { this.AScomp = AScomp; } public void setAScomb(double AScomb) { this.AScomb = AScomb; } // public void setCreatedAt(String created_at){ // this.created_at = created_at; // } // getters public long getASId() { return this.as_id; } public int getASzona() { return this.ASzona; } public int getAStenor() { return this.AStenor; } public double getAStlo() { return this.AStlo; } public double getAScomp() { return this.AScomp; } public double getAScomb() { return this.AScomb; } } and public class EntryEffectiveRate { int er_id; String ERkondisi; int ERtenor; double ERrate; //String created_at; // constructors public EntryEffectiveRate() { } public EntryEffectiveRate(String ERkondisi, int ERtenor, double ERrate) { this.ERkondisi = ERkondisi; this.ERtenor = ERtenor; this.ERrate = ERrate; } public EntryEffectiveRate(int er_id, String ERkondisi, int ERtenor, double ERrate) { this.er_id = er_id; this.ERkondisi = ERkondisi; this.ERtenor = ERtenor; this.ERrate = ERrate; } // setters public void setERId(int er_id) { this.er_id = er_id; } public void setERKondisi(String ERkondisi) { this.ERkondisi = ERkondisi; } public void setERTenor(int ERtenor) { this.ERtenor = ERtenor; } public void setERRate(double ERrate){ this.ERrate = ERrate; } //public void setCreatedAt(String created_at){ // this.created_at = created_at; //} // getters public long getERId() { return this.er_id; } public String getERKondisi() { return this.ERkondisi; } public int getERTenor() { return this.ERtenor; } public double getERrate(){ return this.ERrate; } }
执行/运行mainactivity时的logcat结果
04-07 14:35:11.827: D/Effectiverate Count(395): EffectiverateCount: 15 04-07 14:35:11.837: D/Asuransirate Count(395): AsuransirateCount: 10 04-07 14:35:11.837: D/Get ER(395): GEtting All ER 04-07 14:35:11.837: E/DatabaseHelper(395): SELECT * FROM effective_rate 04-07 14:35:11.847: D/ER_ids(395): 1 04-07 14:35:11.867: D/ER_rates(395): Baru 04-07 14:35:11.867: D/ER_tenors(395): 12 04-07 14:35:11.890: D/ER_rates(395): 12.1 04-07 14:35:11.890: D/ER_ids(395): 2 04-07 14:35:11.890: D/ER_rates(395): Baru 04-07 14:35:11.890: D/ER_tenors(395): 24 04-07 14:35:11.890: D/ER_rates(395): 12.2 04-07 14:35:11.890: D/ER_ids(395): 3 04-07 14:35:11.890: D/ER_rates(395): Baru 04-07 14:35:11.890: D/ER_tenors(395): 36 04-07 14:35:11.890: D/ER_rates(395): 12.3 04-07 14:35:11.897: D/ER_ids(395): 4 04-07 14:35:11.897: D/ER_rates(395): Baru 04-07 14:35:11.897: D/ER_tenors(395): 48 04-07 14:35:11.897: D/ER_rates(395): 12.4 04-07 14:35:11.897: D/ER_ids(395): 5 04-07 14:35:11.897: D/ER_rates(395): Baru 04-07 14:35:11.897: D/ER_tenors(395): 60 04-07 14:35:11.897: D/ER_rates(395): 12.5 04-07 14:35:11.897: D/ER_ids(395): 6 04-07 14:35:11.897: D/ER_rates(395): Baru 04-07 14:35:11.897: D/ER_tenors(395): 12 04-07 14:35:11.897: D/ER_rates(395): 12.6 04-07 14:35:11.897: D/ER_ids(395): 7 04-07 14:35:11.934: D/ER_rates(395): Baru 04-07 14:35:11.934: D/ER_tenors(395): 24 04-07 14:35:11.937: D/ER_rates(395): 12.7 04-07 14:35:11.937: D/ER_ids(395): 8 04-07 14:35:11.937: D/ER_rates(395): Baru 04-07 14:35:11.937: D/ER_tenors(395): 36 04-07 14:35:11.937: D/ER_rates(395): 12.8 04-07 14:35:11.937: D/ER_ids(395): 9 04-07 14:35:11.937: D/ER_rates(395): Baru 04-07 14:35:11.937: D/ER_tenors(395): 48 04-07 14:35:11.937: D/ER_rates(395): 12.9 04-07 14:35:11.937: D/ER_ids(395): 10 04-07 14:35:11.937: D/ER_rates(395): Baru 04-07 14:35:11.937: D/ER_tenors(395): 60 04-07 14:35:11.937: D/ER_rates(395): 13.0 04-07 14:35:11.937: D/Get AS(395): GEtting All AS 04-07 14:35:11.937: E/DatabaseHelper(395): SELECT * FROM asuransi_rate 04-07 14:35:11.947: D/AS_ids(395): 1 04-07 14:35:11.957: D/AS_tenors(395): 12 04-07 14:35:11.957: D/AS_tlos(395): 1.0 04-07 14:35:11.957: D/AS_comps(395): 2.0 04-07 14:35:11.957: D/AS_combs(395): 3.0 . . . 04-07 14:35:12.007: D/AS_ids(395): 15 04-07 14:35:12.007: D/AS_tenors(395): 60 04-07 14:35:12.047: D/AS_tlos(395): 1.14 04-07 14:35:12.047: D/AS_comps(395): 2.14 04-07 14:35:12.047: D/AS_combs(395): 3.14 04-07 14:35:16.258: W/KeyCharacterMap(395): No keyboard for id 0 04-07 14:35:16.258: W/KeyCharacterMap(395): Using default keymap: /system/usr/keychars/qwerty.kcm.bin 04-07 14:35:54.967: D/dalvikvm(395): GC_FOR_MALLOC freed 5071 objects / 280936 bytes in 70ms 04-07 14:35:57.150: W/KeyCharacterMap(395): No keyboard for id 0 04-07 14:35:57.150: W/KeyCharacterMap(395): Using default keymap: /system/usr/keychars/qwerty.kcm.bin 04-07 14:42:28.127: W/IInputConnectionWrapper(395): showStatusIcon on inactive InputConnection 04-07 14:42:33.598: D/dalvikvm(395): GC_EXPLICIT freed 1992 objects / 76432 bytes in 55ms
当它运行时，它将给出消息“未读数据”。 意味着在尝试getExtras时它获得了空值。 我哪里错了？ 我想将所有插入的数据传递给新活动（MediatorMaster，现在用于检查附加组件是否到达那里），然后将计算。 怎么做？ 有什么建议吗？
提前致谢
您在返回之前关闭游标。
如果您要返回游标，请在调用函数中完成游标后关闭游标。
Cursor getAllASrates() { SQLiteDatabase db = this.getWritableDatabase(); Cursor cur = db.rawQuery("Select " + KEY_AS_ID + " as _id, " + KEY_AS_REGIONAL + ", " + KEY_AS_TENOR + ", " + KEY_AS_TLO + ", " + KEY_AS_COMPREHENSIVE + ", " + KEY_AS_COMBINE + ", " + " from " + TABLE_ASURANSI_RATE, new String[] {}); //close the cursor in the calling function after finished with it //cur.close(); return cur; }
这个也是：
Cursor getAllERates() { SQLiteDatabase db = this.getWritableDatabase(); // Cursor cur= // db.rawQuery("Select "+colID+" as _id , "+colName+", "+colAge+" from "+employeeTable, // new String [] {}); // Cursor cur= db.rawQuery("SELECT * FROM "+viewEmps,null); Cursor cur = db.rawQuery("Select " + KEY_ER_ID + " as _id, " + KEY_ER_USEDORNEW + ", " + KEY_ER_TENOR + ", " + KEY_ER_RATE + ", " + " from " + TABLE_EFFECTIVE_RATE, new String[] {}); //close the cursor in the calling function after finished with it //cur.close(); return cur; }
更新：
所以，看起来另一段代码存在问题，所以我修改了它并发布在下面。 尝试直接访问列，不要使用while循环，因为看起来这个游标只返回一个结果。
如果“Cursor count：”日志条目的大小为零，那么您的查询不会返回任何数据。
这也显示了应该关闭光标的位置。
class DataHandler extends Activity { public void getData(int id) { Cursor c = getERValues(id); Log.d(LOG, "Cursor count: " + c.getCount()); if (c != null) { if (c.moveToFirst()) { String UorN = c.getString(0); int er_t = c.getInt(1); double er_r = c.getDouble(2); // use these strings as you want Intent Person = new Intent(this, MediatorMaster.class); Person.putExtra("Used_or_New", UorN); Person.putExtra("ER_tenor", er_t); Person.putExtra("ER_rate", er_r); startActivity(Person); } else{ Log.e(LOG, "Cursor could not moveToFirst "); } } c.close(); //close the cursor here } }
几天后，我找到了解决方案。 感谢Daniel Nugent，Dev和Prashant Bhoir帮助我解决这个问题。解决方案是使用Array作为临时列表，它将读取特定表中的所有数据（您也可以读取特定列）。例如：
从表中的列获取值/某个值*：*它取决于您插入的数据量。数组列表将获取所有数据，如果您没有插入任何值，则它将给出null值。
public List getTheValue(String SomeValue) { List NameOfTheList = new ArrayList (); String selectQuery = "SELECT * FROM " + TABLE_ONE + " where " + KEY_COLUMN_ONE + " = ?"; Log.e(LOG, selectQuery); SQLiteDatabase db = this.getReadableDatabase(); Cursor c = db.rawQuery(selectQuery, new String[] {SomeValue}); // looping through all rows and adding to list if (c.moveToFirst()) { do { TheModelClass AnythingYouWantToNameThis = new TheModelClass(); AnythingYouWantToNameThis.setModelValueNumberOne(c.getString(c.getColumnIndex(KEY_COLUMN_ONE))); // add NameOfTheList.add(AnythingYouWantToNameThis); } while (c.moveToNext()); } //always close the cursor after using it cause it may cause memory leak c.close(); return NameOfTheList; }
要从表中获取值/某个值：
public List getAllNameOfTheList() { List NameOfTheList = new ArrayList (); String selectQuery = "SELECT * FROM " + TABLE_ONE; Log.e(LOG, selectQuery); SQLiteDatabase db = this.getReadableDatabase(); Cursor c = db.rawQuery(selectQuery, null); // looping through all rows and adding to list if (c.moveToFirst()) { do { TheModelClass SomeName = new TheModelClass(); SomeName.setValueNumberOne(c.getString(c.getColumnIndex(KEY_COLUMN_ONE))); SomeName.setValueNumberTwo(c.getInt(c.getColumnIndex(KEY_COLUMN_TWO))); SomeName.setValueNumberThree(c.getDouble(c.getColumnIndex(KEY_COLUMN_THREE))); SomeName.setValueNumberFour(c.getLong(c.getColumnIndex(KEY_COLUMN_FOUR))) . . . SomeName.setValueNumberX(c.getSomeDataTypeBasedOnTheTypeYouHaveSetInTheModelClass(c.getColumnIndex(THE_COLUMN))) // add NameOfTheList.add(SomeName); } while (c.moveToNext()); } // db.close(); c.close(); return NameOfTheList; }
然后在类上调用它（假设这个类是数据库值处理程序）对于1列：
// Database YourDatabaseClass db; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.testgetdata); db = new YourDatabaseClass(getApplicationContext()); List Anything = db.getValue(); TheModelClass Value0 = Anything.get(0); TheModelClass Value1 = Anything.get(1); . . . TheModelClass ValueX = Anything.get(X*); String Value0 = Value0.getValue(); //2nd column String Value1 = Value1.getValue(); //column X String ValueX = ValueX.getValue(); Intent person = new Intent(this, NameOfTheClassThatYouWantToHaveThisValues.class); Bundle backpack = new Bundle(); backpack.putString("AKA_47", Value0); backpack.putString("Missile", Value1); . . . backpack.putString("Anything", ValueX); person.putExtras(backpack); setResult(RESULT_OK, person); startActivity(person); // Don't forget to close database connection db.closeDB();
对于多个Column：// Database YourDatabaseClass db;
@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.testgetdata); db = new YourDatabaseClass(getApplicationContext()); List Anything = db.getAllDataOfTheList(); TheModelClass Value0 = Anything.get(0); TheModelClass Value1 = Anything.get(1); . . . TheModelClass ValueX = Anything.get(X*); /*Based on how many row you have, Start with row 0 (zero) * whenever TheModelClass Value0 = Anything.get(0); called then you will have * column0Value0 column01alue1 column2Value2.........columnXValueX */ long Value0FromColumn0 = Value0.getId(); String Value1FromColumn0 = Value0.getName(); int Value2FromColumn0 = Value0.getPhoneNumber(); double Value3FromColumn0 = Value0.getETC(); //2nd column long Value0FromColumn1 = Value1.getId(); String Value1FromColumn1 = Value1.getName(); int Value2FromColumn1 = Value1.getPhoneNumber(); double Value3FromColumn1 = Value1.getETC(); //column X long ValueXFromColumnX = ValueX.getId(); String ValueXFromColumnX = ValueX.getName(); int ValueXFromColumnX = ValueX.getPhoneNumber(); double ValueXFromColumnX = ValueX.getETC(); Intent person = new Intent(this, NameOfTheClassThatYouWantToHaveThisValues.class); Bundle backpack = new Bundle(); backpack.putLong("Pencil", Value0FromColumn0); backpack.putString("Book", Value1FromColumn0); backpack.putInt("Laptop", Value2FromColumn); backpack.putDouble("Nuclear_BOMB", Value3FromColumn0); backpack.putLong("Spiderman", Value0FromColumn1); backpack.putString("IronMan", Value1FromColumn1); backpack.putInt("Hercules", Value2FromColumn1); backpack.putDouble("MasterYoda", Value3FromColumn1); . . . backpack.putLong("Monkey", ValueXFromColumnX); backpack.putString("Dolphin", ValueXFromColumnX); backpack.putInt("Alien", ValueXFromColumnX); backpack.putDouble("Predator", ValueXFromColumnX); person.putExtras(backpack); setResult(RESULT_OK, person); startActivity(person); // Don't forget to close database connection db.closeDB();
然后在另一个类中接收多个列的值：
@Override protected void onCreate(Bundle bundle) { // TODO Auto-generated method stub super.onCreate(bundle); setContentView(R.layout.test); Bundle exploded = this.getIntent().getExtras(); if (this.getIntent().getExtras() != null) { long id0 = exploded.getLong("Pencil"); String name0 = exploded.getString("Book"); int phoneNumber0 = exploded.getInt("Laptop"); double etc0 = exploded.getDouble("Nuclear_BOMB"); . . . long X = exploded.getLong("X"); String Y = exploded.getString("Y"); int Z = exploded.getInt("Z"); double W = exploded.getDouble("W"); } else { Message.message(this, "unread datas"); }}
对于一列：
Bundle exploded = this.getIntent().getExtras(); if (this.getIntent().getExtras() != null) { String something0 = exploded.getString("AKA_47"); String anything0 = exploded.getString("Missile"); String whatever0 = exploded.getString("Anything"); . . . String X = exploded.getString("X"); } else { Message.message(this, "unread datas"); }
如果你想知道什么是Message.message，它是一个类。代码：
import android.content.Context; import android.widget.Toast; public class Message { public static void message(Context context, String message) { Toast.makeText(context, message, Toast.LENGTH_LONG).show(); } }
然后你有他们。 快乐的编码！