Re: Hibernate, mySQL and formatting dates

From:
Lew <lew@lewscanon.com>
Newsgroups:
comp.lang.java.programmer
Date:
Fri, 22 May 2009 12:24:50 -0700 (PDT)
Message-ID:
<7ba619a0-f3e6-4e33-9dba-4ebf939b8d75@v4g2000vba.googlegroups.com>
On May 22, 1:39 pm, "Alessandro" <n...@nobody.it> wrote:

I'm writing some Date values into datetime fields inside a mySQL table us=

ing

hibernate (in the mapping file all that fields were declared as "date").


The 'Date' component of a 'java.sql.Timestamp' holds time information
to a resolution of one second. 'java.util.Date' itself has one-
millisecond resolution.

The MySQL DATETIME type holds time information to a resolution of one
second.

Everything works fine but I view also hh:mm:ss and I wouldn't view that i=

n

the mySQL table.


Then format your view differently. You are seeing the data type with
the resolution that it supports.

The Date object has been formatted using SimpleDateFormat ("yyyy-MM-dd"),


'Date' objects don't get formatted. Formatting happens only to
'String' values.

time information shouldn't be valorized


What does 'valorized' mean?

but then setting in the table I view also time as 00:00:00.


Because that is what you set the time portion of the 'Date' to.

Then do I need to set in some way tha date format:

1) in mySQL


You might consider defining the column as 'DATE' type. Consider
reading the MySQL documentation.
<http://dev.mysql.com/doc/refman/5.1/en/datetime.html>

2) somewhere in hibernate


No.

3) transform datetime field into string and map it as "string", but this =

is

a poor workaround


Bear in mind that Java's 'Date' and 'Timestamp' types are binary types
- they do not get formatted.

The same is true of MySQL's (non-standard) 'DATE', 'DATETIME' and
'TIMESTAMP' types.

4) else


You are storing the values exactly as you told the system to, as
'DATETIME' types with the hour/minute/second portion zeroed out.
These binary types do not get formatted; the concept is meaningless.
You can format the output from your MySQL query differently if you
wish; that is an operation performed on the string representation of
the 'DATETIME' binary value.

--
Lew

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