I have a part of code which returns an array after querying the database but when I run the the application , it crashes
//info is the name of the object of the type DataBase
info.open();
String[] data = info.queryAll();
info.close();
Part of the database code , where I am trying to retrieve all the rows of Database of a certain column
public String[] queryAll() {
String[] columns = new String[] { KEY_NAME };
Cursor cursor = ourDatabase.query(DATABASE_TABLE, columns, null, null,
null, null, null);
if (cursor != null) {
try {
final int nameColumnIndex = cursor.getColumnIndex(KEY_NAME);
List<String> names = new ArrayList<String>();
while (cursor.moveToNext()) {
names.add(cursor.getString(nameColumnIndex));
}
return names.toArray(new String[names.size()]);
} finally {
cursor.close();
}
}
return null;
}
Is it because my DataBase is null in the beginning??If so how do I correct the code ??
All suggestions will be helpful’
Thank You
LOGCAT
09-23 22:26:47.780: E/AndroidRuntime(2825): FATAL EXCEPTION: main
09-23 22:26:47.780: E/AndroidRuntime(2825): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.contactlist/com.example.contactlist.Contacts}: android.database.sqlite.SQLiteException: no such table: mycontacts (code 1): , while compiling: SELECT Contact_name FROM mycontacts
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread.access$600(ActivityThread.java:130)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.os.Handler.dispatchMessage(Handler.java:99)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.os.Looper.loop(Looper.java:137)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread.main(ActivityThread.java:4745)
09-23 22:26:47.780: E/AndroidRuntime(2825): at java.lang.reflect.Method.invokeNative(Native Method)
09-23 22:26:47.780: E/AndroidRuntime(2825): at java.lang.reflect.Method.invoke(Method.java:511)
09-23 22:26:47.780: E/AndroidRuntime(2825): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
09-23 22:26:47.780: E/AndroidRuntime(2825): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
09-23 22:26:47.780: E/AndroidRuntime(2825): at dalvik.system.NativeStart.main(Native Method)
09-23 22:26:47.780: E/AndroidRuntime(2825): Caused by: android.database.sqlite.SQLiteException: no such table: mycontacts (code 1): , while compiling: SELECT Contact_name FROM mycontacts
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:882)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:493)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1161)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1032)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1200)
09-23 22:26:47.780: E/AndroidRuntime(2825): at com.example.contactlist.DBContact.queryAll(DBContact.java:97)
09-23 22:26:47.780: E/AndroidRuntime(2825): at com.example.contactlist.Contacts.onCreate(Contacts.java:38)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.Activity.performCreate(Activity.java:5008)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
09-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
09-23 22:26:47.780: E/AndroidRuntime(2825): ... 11 more
DATABASE CODE
public class DBContact {
public static final String KEY_ROWID = "_id";
public static final String KEY_NAME = "Contact_name";
public static final String KEY_PERSONALPHONE = "Personal_Phonenumber";
public static final String KEY_HOMEPHONE = "Home_Phonenumber";
public static final String KEY_OFFICEPHONE = "Office_Phonenumber";
private static final String DATABASE_NAME = "Contact_name";
private static final String DATABASE_TABLE = "mycontacts";
private static final int DATABASE_VERSION = 1;
// Instance of the class DbHelper
private DbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourDatabase;
public static final String[] KEYS_ALL = { DBContact.KEY_ROWID,
DBContact.KEY_NAME, DBContact.KEY_PERSONALPHONE,
DBContact.KEY_HOMEPHONE, DBContact.KEY_OFFICEPHONE };
private static class DbHelper extends SQLiteOpenHelper {
private static final String DATABASE_CREATE = "create table contacts (_id integer primary key autoincrement, "
+ "Contact_name text not null, Personal_Phonenumber text not null, Home_Phonenumber text not null, Office_Phone text not null); ";
public DbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase ourDatabase) {
// TODO Auto-generated method stub
try {
ourDatabase.execSQL(DATABASE_CREATE);
} catch (SQLException e) {
e.printStackTrace();
}
}
@Override
public void onUpgrade(SQLiteDatabase ourDatabase, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
ourDatabase.execSQL("DROP TABLE IF EXISTS contacts");
onCreate(ourDatabase);
}
}
// Context of constructor withhin our Class
public DBContact(Context c) {
ourContext = c;
}
// Opens the database
public DBContact open() throws SQLException {
// Constructor for DB Helper class takes in a Context
// Context is passed in is "ourContext" for within our class
ourHelper = new DbHelper(ourContext);
// Passes in DB Name and Version
// ourDatabase is of type SQLite DataBase
ourDatabase = ourHelper.getWritableDatabase();
return this;
}
// Closes the database connection
public void close() {
// refer to our DbHelper and close the SQLite DataBase Helper
ourHelper.close();
ourHelper = null;
ourDatabase = null;
}
// Deletes the Row
public boolean deleteRow(long rowId) {
return ourDatabase.delete(DATABASE_TABLE, DBContact.KEY_ROWID + "="
+ rowId, null) > 0;
}
public String[] queryAll() {
String[] columns = new String[] { KEY_NAME };
Cursor cursor = ourDatabase.query(DATABASE_TABLE, columns, null, null,
null, null, null);
if (cursor != null) {
try {
final int nameColumnIndex = cursor.getColumnIndex(KEY_NAME);
List<String> names = new ArrayList<String>();
cursor.moveToFirst();
while (cursor.moveToNext()) {
names.add(cursor.getString(nameColumnIndex));
}
return names.toArray(new String[names.size()]);
} finally {
cursor.close();
}
}
return null;
}
/*public Cursor queryAll(){
String[] columns = new String[] {KEY_NAME};
return ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
if(data == null){
columns[0] = "NO CONTACTS PRESENT";
return columns;
}else{
return columns;
}
}*/
public long newRow(String name, String pphone, String hphone, String ophone) {
// TODO Auto-generated method stub
ContentValues newvalue = new ContentValues();
newvalue.put(KEY_NAME, name);
newvalue.put(KEY_PERSONALPHONE, pphone);
newvalue.put(KEY_HOMEPHONE, hphone);
newvalue.put(KEY_OFFICEPHONE, ophone);
return ourDatabase.insert(DATABASE_TABLE, null, newvalue);
}
public String getName(Long l) {
// TODO Auto-generated method stub
String[] columns = new String[] { KEY_ROWID, KEY_NAME,
KEY_PERSONALPHONE, KEY_HOMEPHONE, KEY_OFFICEPHONE };
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "="
+ 1, null, null, null, null);
if (c != null) {
c.moveToFirst();
String name = c.getString(1);
return name;
}
return null;
}
public String getPphone(Long l) {
// TODO Auto-generated method stub
String[] columns = new String[] { KEY_ROWID, KEY_NAME,
KEY_PERSONALPHONE, KEY_HOMEPHONE, KEY_OFFICEPHONE };
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "="
+ 1, null, null, null, null);
if (c != null) {
c.moveToFirst();
String Pphone = c.getString(2);
return Pphone;
}
return null;
}
public String getHphone(Long l) {
// TODO Auto-generated method stub
String[] columns = new String[] { KEY_ROWID, KEY_NAME,
KEY_PERSONALPHONE, KEY_HOMEPHONE, KEY_OFFICEPHONE };
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "="
+ 1, null, null, null, null);
if (c != null) {
c.moveToFirst();
String Hphone = c.getString(3);
return Hphone;
}
return null;
}
public String getOphone(Long l) {
// TODO Auto-generated method stub
String[] columns = new String[] { KEY_ROWID, KEY_NAME,
KEY_PERSONALPHONE, KEY_HOMEPHONE, KEY_OFFICEPHONE };
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "="
+ 1, null, null, null, null);
if (c != null) {
c.moveToFirst();
String Ophone = c.getString(4);
return Ophone;
}
return null;
}
}
Office_Phone in the above code and the declaration do not match . Also what others said.