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From "domenico di leo" <domenico.di...@gmail.com>
Subject Re: Null
Date Thu, 28 Jun 2007 07:19:59 GMT
Ok I 've understand, but what way you pick the element from String[] ?


On 28/06/07, PTS <parsonstechnical@gmail.com> wrote:
> In several of the fields of the database the information is not entered
> until a later time and thus the field is null. If you look at actual data
> the value is null. When returned the data either is "null" or is not
> compatible with the data needed back. I am using the data in several areas.
> If I am expecting a String and it is null, then I want an empty string to be
> displayed. If I am expecting a number then I want a 0 if it is null. If the
> data returned is not of the type expected then I catch the exception and
> return the equivalent of no information for that data type.
>
> As for the String[], I am pulling back an entire row from the database and
> then picking a single element from the array. In essence it allows me to
> treat the result set as a two dimensional array.
>
> The concept that I was trying to convey to the OP was to do a try catch and
> return the desired default value of the proper type.
>
> Doug
>
> ----- Original Message -----
> From: "domenico di leo" <domenico.dileo@gmail.com>
> To: "Tomcat Users List" <users@tomcat.apache.org>
> Sent: Wednesday, June 27, 2007 7:08 AM
> Subject: Re: Null
>
>
> > If I have understand your problem is : you receive a lot of null value
> > afther a query but you don't except them.
> > The problem could be in your if statement .
> >
> > ((String[])queryResults.elementAt(r))[c]).equalsIgnoreCase("null"))
> >
> > you compare a String vector with a String because you have upacsted to
> > String[]  the return value of queryResult.
> > I think you should do something like this:
> >
> > String[] queryResult = new String[10]
> > /* Suppose that the queryResult method yelds a vector fill with 10 String
> >
> > queryResult = new ((String[])queryResults.elementAt(r))[c])
> >
> > afther
> >
> > for (int i=0; i<= queryResult.lenght(); i++){
> > if queryResult[i].equalsIgnoreCase("null"))
> >    return null; // Why do you use "" ?
> >  return queryResult[i];
> > }
> >
> > Cheers
> >
> > On 25/06/07, Propes, Barry L <barry.l.propes@citi.com> wrote:
> >> yeah, this seems like a good solution, too.
> >>
> >> -----Original Message-----
> >> From: PTS [mailto:parsonstechnical@gmail.com]
> >> Sent: Saturday, June 23, 2007 12:29 PM
> >> To: Tomcat Users List
> >> Subject: Re: Null
> >>
> >>
> >> I had to deal with a lot of null values coming back from a database. I
> >> may
> >> have been reinventing the wheel but I wrote a little DBUtil class that I
> >> used to sanitize the returned data. I wrote a get for each type of data
> >> and
> >> did a try catch. If the data came back not null I simply returned it, if
> >> it
> >> came back null it threw an exception and I returned back a default value
> >> in
> >> the catch clause.
> >>
> >> For text:
> >>
> >>    /** returns the row and column equivalent from the DBResults or empty
> >> string if null or out of bounds*/
> >>   public String getDataP(int r, int c){
> >>    try{
> >>     if
> >> ((((String[])queryResults.elementAt(r))[c]).equalsIgnoreCase("null"))
> >>      return "";
> >>    return(((String[])queryResults.elementAt(r))[c]);
> >>   }catch(Exception e){return "";}
> >>   }
> >>
> >> For numbers:
> >>
> >>    /** returns the row and column equivalent from the DBResults or string
> >> 0
> >> if null or out of bounds*/
> >>   public String getDataN(int r, int c){
> >>    try{
> >>     if
> >> ((((String[])queryResults.elementAt(r))[c]).equalsIgnoreCase("null"))
> >>      return "0";
> >>    return(((String[])queryResults.elementAt(r))[c]);
> >>   }catch(Exception e){return "0";}
> >>   }
> >>
> >>
> >> For time:
> >>
> >>     /** returns the row and column equivalent from the DBResults or
> >> string
> >> 00:00:00 if null or out of bounds*/
> >>   public String getDataT(int r, int c){
> >>    try{
> >>     if
> >> ((((String[])queryResults.elementAt(r))[c]).equalsIgnoreCase("null"))
> >>      return "00:00:00";
> >>    return(((String[])queryResults.elementAt(r))[c]);
> >>   }catch(Exception e){return "00:00:00";}
> >>   }
> >>
> >>
> >> Doug
> >>
> >> ----- Original Message -----
> >> From: "Propes, Barry L " <barry.l.propes@citi.com>
> >> To: "Tomcat Users List" <users@tomcat.apache.org>
> >> Sent: Friday, June 22, 2007 1:11 PM
> >> Subject: RE: Null
> >>
> >>
> >> that doesn't sound right....are you sure you're pulling back a value from
> >> a
> >> column that's a string?
> >>
> >> -----Original Message-----
> >> From: Mohammed Zabin [mailto:jotnarta@gmail.com]
> >> Sent: Thursday, June 21, 2007 6:02 AM
> >> To: Tomcat Users List
> >> Subject: Re: Null
> >>
> >>
> >> I tried it the other way, if( rs.getString("field") == null ) but the
> >> compiler plames that null can't be compared to string....
> >>
> >> On 6/21/07, Tim Funk <funkman@joedog.org> wrote:
> >> >
> >> >
> >> > if (null == rs.getString("col_foo")) {
> >> >    out.println("<td>&nbsp;</td>");
> >> > } else {
> >> >    // Evil since this doesn't escape the xml - for edutainment only
> >> >    out.println("<td>" + rs.getString("col_foo") + "</td>");
> >> > }
> >> >
> >> > -Tim
> >> >
> >> > Mohammed Zabin wrote:
> >> > > Hi All
> >> > >
> >> > > Anyone knows how to deal with null values in JDBC ResultSet??
> >> > >
> >> > > I am trying to render a table in jsp page that read its value from
> >> > > the
> >> > > database, sometimes, the database returns null values, and so, the
> >> > > whole
> >> > > table couldn't be rendered. Is there any way to deal with null
> >> > > values.
> >> > >
> >> > > Thanks
> >> > >
> >> >
> >> >
> >> > ---------------------------------------------------------------------
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> >> >
> >> >
> >>
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> >>
> >
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> >
>
>
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>

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