RE: DATETIME type in mysql?

From: Twan Kogels (twa..wansoft.com)
Date: Fri Oct 15 2004 - 03:43:02 EDT

  • Next message: Twan Kogels: "Re: DATETIME type in mysql?"

    Hello Lindsay,

    Thanks for the tip, i'm now using java.sql.Timestamp which seems to be a
    subclass of java.util.Date. That's also working good, but i'm going to try
    java.util.Date next.

    Cheers,
    Twan

    At 22:53 14-10-2004, you wrote:

    >The DATETIME you are talking about in MySQL maps quite well to the Date
    >in the modeller.
    >
    > A (DATE) java.util.date has both a time and a date - so it is well
    >matched to the DATETIME.
    >
    > I also use the Date and Time fields seperately in MySQL .. And map both
    >to a java.util.date then just extract the bit I need when nessasary.
    >
    >-----Original Message-----
    >From: Twan Kogels [mailto:twa..wansoft.com]
    >Sent: Friday, 15 October 2004 5:21 AM
    >To: cayenne-use..bjectstyle.org
    >Subject: DATETIME type in mysql?
    >
    >
    >Hello all,
    >
    >I've testing my webapplication and found a problem when using TIMESTAMP
    >with mysql.
    >
    >In mysql the TIMESTAMP type does not act like a normal TIMESTAMP. I'll
    >quote: ============ The TIMESTAMP column type provides a type that you
    >can use to automatically
    >mark INSERT or UPDATE operations with the current date and time. If you
    >have multiple TIMESTAMP columns in a table, only the first one is
    >updated
    >automatically.
    >============ <http://dev.mysql.com/doc/mysql/en/TIMESTAMP_pre-4.1.html>
    >
    >This means when you don't specify a value for TIMESTAMP mysql just
    >overwrites the current value with a new time value. That's kind of
    >stupid.
    >
    >Mysql also has a DATETIME type, that's used for date+time values, for
    >example "10-10-2004 10:29". I've looked into the Modeler but could not
    >find
    >the DATETIME type for a DBentity. I've found DATE (only used for dates
    >"10-10-2004") and TIME (only used for time "10:29").
    >
    >If you want to use date and time then the only choice seems to
    >TIMESTAMP,
    >but that type has very strange non standard effects in mysql.
    >
    >In mysql 4.1 you can turn off the strange effects of TIMESTAMP, but 4.1
    >version is still only for development.
    >
    >In my situation i've got 2 TIMESTAMP columns, one is always filled, but
    >one
    >can be NULL (or empty). But in mysql a TIMESTAMP can't be NULL/empty.
    >When
    >i specify NULL mysql's non standard function get activated which inserts
    >
    >the current time in my NULL column.
    >
    >Does cayenne supports DATETIME type of mysql or is there any other way
    >around the TIMESTAMP problem?
    >
    >Cheers,
    >Twan (thinking about throwing mysql away)



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