null pointer when query database

Question

i am searching for a number in my database and weather it exists in it or not and return a boolean but the query always gives me a null pointer exception when it is run

query

public boolean getPhone(String where){
    Cursor cur = db.query(DATABASE_TABLE, new String [] {ID,PHONE_NUMBER},PHONE_NUMBER + "='" + where + "'",null,null,null,null); //fails here at the query
        Log.v("Cursor", cur.toString());
        String test = null;
        if(cur.moveToFirst()){
            do{
                test = cur.getString(cur.getColumnIndex(PHONE_NUMBER));
                Log.v("ContactDB", test);
            }while(cur.moveToNext());
            return true;
        }
            return false;
    }

implementation

        ContactDB db = new ContactDB(arg0);
        boolean dbNumber = db.getPhone(from);//searchNumber(arg0,from);
        if(dbNumber == true){
             //if number exists do stuff
        }else{
             //if number does not exist do other stuff
        }

it always fails at the query

03-16 11:57:06.522: ERROR/AndroidRuntime(28579): FATAL EXCEPTION: main
03-16 11:57:06.522: ERROR/AndroidRuntime(28579): java.lang.RuntimeException: Unable to start receiver com.app.notifyme.SmsReciever: java.lang.NullPointerException
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at android.app.ActivityThread.handleReceiver(ActivityThread.java:1805)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at android.app.ActivityThread.access$2400(ActivityThread.java:117)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:981)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at android.os.Handler.dispatchMessage(Handler.java:99)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at android.os.Looper.loop(Looper.java:123)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at android.app.ActivityThread.main(ActivityThread.java:3683)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at java.lang.reflect.Method.invokeNative(Native Method)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at java.lang.reflect.Method.invoke(Method.java:507)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at dalvik.system.NativeStart.main(Native Method)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579): Caused by: java.lang.NullPointerException
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at com.app.notifyme.ContactDB.getPhone(ContactDB.java:87)
03-16 11:57:06.522: ERROR/AndroidRuntime(28579):     at com.app.notifyme.SmsReciever.onReceive(SmsReciever.java:55)

03-16 11:57:06.522: ERROR/AndroidRuntime(28579): at android.app.ActivityThread.handleReceiver(ActivityThread.java:1794)

Where is line 87 in ContactDB.java?

Erich Douglass
– Erich Douglass

2011-03-16 16:59:21 +00:00
Commented Mar 16, 2011 at 16:59 — Erich Douglass
– Erich Douglass, Commented Mar 16, 2011 at 16:59

Cristian · Accepted Answer · 2011-03-16 17:06:47Z

2

You must open the database:

ContactDB db = new ContactDB(arg0);
db.open();

or it will throw NPEs. Don't forget to close it once you don't need it anymore.

answered Mar 16, 2011 at 17:06

Cristian

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1 Comment

tyczj Over a year ago

but the method getPhone is in the database class so it should not need to be opened right? *edit oh nevermind i just noticed i didnt open it when i called the getPhone method

Matthew · Accepted Answer · 2011-03-16 17:07:15Z

0

Try changing up your db.query( ... ) line:

Cursor cur = db.query(
  DATABASE_TABLE,
  new String [] {ID,PHONE_NUMBER},
  PHONE_NUMBER + " = " + theNumber,
  null, null, null, null, null);

As per the documentation, your selection argument should not contain the WHERE keyword.

answered Mar 16, 2011 at 17:07

Matthew

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1 Comment

Manish Khot Over a year ago

here where is a String which is passed as a parameter in the following method getPhone(String where).

user590849 · Accepted Answer · 2011-03-16 17:25:45Z

0

the db needs to be opened. Also try executing the sql query using the rawquery(query,selectionargs) method.

answered Mar 16, 2011 at 17:25

user590849

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