Re: Re: [INTERFACES] Trouble with JDBC2 ResultSet.getDate() - Mailing list pgsql-jdbc

From Bruce Momjian
Subject Re: Re: [INTERFACES] Trouble with JDBC2 ResultSet.getDate()
Date
Msg-id 200105301634.f4UGYrV08160@candle.pha.pa.us
Whole thread Raw
In response to Re: [INTERFACES] Trouble with JDBC2 ResultSet.getDate()  (Palle Girgensohn <girgen@partitur.se>)
List pgsql-jdbc
Patch applied.  Standards require it.  If Peter adds casting later, this
can be removed.  We are clearly seeing problem reports about this.

Thanks.


> Hi!
>
> I just got bitten by this too. I use type timestamp in the
> database, and often need the latest timestamp, but want to
> format it as a date. With 7.0.x, I just
>
>  select ts from foo order by ts desc limit 1
>
> and in java: d = res.getDate(1);
>
> but this fails everywhere in my code now :(
>
> The problem is this optimization in
> src/interfaces/jdbc/org/postgresql/jdbc2/ResultSet.java,
> introduced in 1.21:
>
> @@ -418,12 +418,8 @@
>      String s = getString(columnIndex);
>      if(s==null)
>        return null;
> -    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
> -    try {
> -      return new java.sql.Date(df.parse(s).getTime());
> -    } catch (ParseException e) {
> -      throw new PSQLException("postgresql.res.baddate",new
> Integer(e.getErrorOffset()),s);
> -    }
> +
> +    return java.sql.Date.valueOf(s);
>    }
>
>    /**
>
>
> Log string is:
>
>    - Removed need for SimpleDateFormat in ResultSet.getDate()
>      improving performance.
>
> I cannot find any reference to whether it is bad or not to let
> getDate return a date when the string from postgres is a
> timestamp or datetime. It appears to me as a good feature, and
> since it has been working for quite som time, and the postgres
> documenation recommends timestamp as the best time & date type,
> is it really necessary to break functionality for many users
> this way? The performance fix is good, but I think code shall
> be added to make it backward compatible.
>
> My query will need to be rewritten like this:
>
>  select ts::date as d, ts from foo order by ts desc limit 1
>
> and I have hundreds of them :(
>
> Maybe we can introduce a try-catch clause to handle the case
> where the string is really a timestamp and not a pure date, but
> this would give users the false impression that everything is
> OK, and exceptions are really a performance hog... Maybe just
> check if the string size is > 10, and then use the old code?
> Agree, this would make it complicated.
>
> /Palle
>
>
> Juhan-Peep Ernits wrote:
> >
> > System is Debian "woody"
> > java is IBM SDK1.3
> > Source is CVS from March 20, 2001.
> >
> > Trouble is the following, that
> >
> > org.postgresql.jdbc2.ResultSet.getDate(int)
> >
> > Started to generate errors
> >
> > java.lang.NumberFormatException: 15 14:25:17+02
> >         at java.lang.Integer.parseInt(Integer.java:415)
> >         at java.lang.Integer.parseInt(Integer.java:455)
> >         at java.sql.Date.valueOf(Date.java:97)
> >         at org.postgresql.jdbc2.ResultSet.getDate(ResultSet.java:427)
> >         at org.postgresql.jdbc2.ResultSet.getDate(ResultSet.java:665)
> > ...
> >
> > when fetching dates from fields of timestamp
> > type. It seems that the fixes provided in CVS version 1.18 from Jan 24
> > 23:41:04 2001 of ResultSet.java regarding getDate() method broke it for
> > our application. Now I went back to 1.17 and copied the
> >
> >   SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
> >
> >      try {
> >        return new java.sql.Date(df.parse(s).getTime());
> >      } catch (ParseException e) {
> >        throw new PSQLException("postgresql.res.baddate",new
> > Integer(e.getErrorOffset()),s);
> >      }
> >
> > part to replace the new code:
> >
> >      return java.sql.Date.valueOf(s);
> >
> > and it works fine but I have not had time to debug this any further. May
> > be it would be nice to have that part of the old code included in the 7.1
> > release driver?
> >
> > Regards,
> >
> > Juhan Ernits
> >
> > ---------------------------(end of broadcast)---------------------------
> > TIP 6: Have you searched our list archives?
> >
> > http://www.postgresql.org/search.mpl
>
> --
>          Partitur Informationsteknik AB
> Wenner-Gren Center             +46 8 566 280 02
> 113 46 Stockholm           +46 70 785 86 02
> Sweden                   girgen@partitur.se
>
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--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026
--- src/interfaces/jdbc/org/postgresql/jdbc1/ResultSet.java~    Fri Feb 23 19:12:23 2001
+++ src/interfaces/jdbc/org/postgresql/jdbc1/ResultSet.java    Wed May  9 04:31:11 2001
@@ -423,8 +423,13 @@
     String s = getString(columnIndex);
     if(s==null)
       return null;
-
-    return java.sql.Date.valueOf(s);
+    // length == 10: SQL Date
+    // length >  10: SQL Timestamp, assumes PGDATESTYLE=ISO
+    try {
+      return java.sql.Date.valueOf((s.length() == 10) ? s : s.substring(0,10));
+    } catch (NumberFormatException e) {
+      throw new PSQLException("postgresql.res.baddate", s);
+    }
   }

   /**
@@ -441,8 +446,13 @@

     if(s==null)
       return null; // SQL NULL
-
-    return java.sql.Time.valueOf(s);
+    // length == 8: SQL Time
+    // length >  8: SQL Timestamp
+    try {
+      return java.sql.Time.valueOf((s.length() == 8) ? s : s.substring(11,19));
+    } catch (NumberFormatException e) {
+      throw new PSQLException("postgresql.res.badtime",s);
+    }
   }

   /**

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