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Showing entries 1 to 10 of 13 3 Older Entries

Displaying posts with tag: timestamp (reset)

time for standards 2
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I was a bit wrong in my previous post. MySQL 5.6 does allow you to supply a fsp with CURRENT_TIMESTAMP (thanks Roy).

mysql> SELECT CURRENT_TIMESTAMP,CURRENT_TIMESTAMP(6);
+---------------------+----------------------------+
| CURRENT_TIMESTAMP | CURRENT_TIMESTAMP(6) |
+---------------------+----------------------------+
| 2013-10-27 10:38:59 | 2013-10-27 10:38:59.182530 |
+---------------------+----------------------------+
1 row in set (0.00 sec)


It however feels a bit weird to me as the …










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time for standards
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MySQL 5.6 includes support for microsecode timestamp resolution, which is a great new feature.

To get the current timestamp in MySQL 5.5 you could use NOW(), SYSDATE() or CURRENT_TIMESTAMP.

mysql_5.5> SELECT NOW(),SYSDATE(),CURRENT_TIMESTAMP;
+---------------------+---------------------+---------------------+
| NOW() | SYSDATE() | CURRENT_TIMESTAMP |
+---------------------+---------------------+---------------------+
| 2013-10-26 15:46:24 | 2013-10-26 15:46:24 | 2013-10-26 15:46:24 | …







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Recovering temporal types in MySQL 5.6: TIME, TIMESTAMP and DATETIME
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MySQL 5.6 introduces a new feature – microseconds resolution in some temporal types. As of 5.6.4 TIME, TIMESTAMP and DATETIME can have a fractional part. To create a field with subseconds you can specify precision in brackets: TIME(3), DATETIME(6) etc.

Obviously, the new feature requires the format change. All three types may now have a tail with a fractional part. The tail may be one, two or three bytes long and can store up to six digits after the point.

The non-fractional part has …

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Fixing awkward TIMESTAMP behaviors...
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There are great features in MySQL 5.6. But not only that. We also tried to correct some old behaviors and limitations which, over the years, have shown to irritate our Community. The behavior of TIMESTAMP columns is one of them.

My colleague Martin Hansson did most of the work and summarized it well in his blog. Thanks to him, since MySQL 5.6.5, it's possible to declare more than one TIMESTAMP column with the DEFAULT CURRENT_TIMESTAMP or ON UPDATE CURRENT_TIMESTAMP attributes. And it's possible to have DATETIME columns …

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TIMESTAMP data types and CURRENT_TIMESTAMP attribute
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In the yet to be released MySQL 5.6.6 DMR, there has been a change to the restriction of just one TIMESTAMP column with the DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP syntax. It is now possible for any TIMESTAMP to have either column defintion.

More information at http://dev.mysql.com/doc/refman/5.6/en/news-5-6-5.html

How To – Convert MSSQL Timestamp/Datetime to Unix Timestamp
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Background Knowledge

I will explain how to convert a DATETIME (data type) value in Microsoft SQL Server to Unix timestamp and how to convert Unix timestamp to DATETIME. A Unix timestamp is a integer value of seconds since January 1, 1970 at midnight. For further explanation of Unix timestamps refer to Wikiepedia, UnixTimestamp.com or http://unixtimesta.mp/.

Note: This solution only work on dates prior to 2038-01-19 at 3:14:08 AM, where the …

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Disable ON UPDATE CURRENT_TIMESTAMP in MySQL
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In a few scenarios, I prefer using the data-type TIMESTAMP of MySQL, with the flag ON UPDATE CURRENT_TIMESTAMP. This is much easier and even faster than using a trigger which sets a specified column to NOW() or CURRENT_DATE(). I love this feature, when it comes to set last modified flags of tables. Now, I encountered a problem with a tagging table by using the flag. Every tag in the table has besides the tag-name, also the aggregated number of relations and a timestamp of last update (or the insert). Everything is okay, until you want to update the aggregated column, when the numbers are wrong for any reason. …

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Detecting invalid and zero temporal values
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I’ve been thinking a lot about invalid and zero temporal values and how to detect them with MySQL date and time functions because mk-table-checksum has to handle “everything” correctly and efficiently. The requirements are complex because we have to take into account what MySQL allows to be stored verses what it allows to be used in certain operations and functions, how it sorts a mix of real and invalid temporal values for MIN() and MAX(), how to detect a temporal value as equivalent to zero, and how different MySQL versions …

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Creating a MySQL plugin to produce an integer timestamp
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This article shows how to create a MySQL-plugin that can be used to create a function which can in turn be used in stored procedures. The function will produce an integer value representing the time (to the nearest usec).

I’m working on an article for conflict detection/resolution when using MySQL Cluster asynchronous replication which requires an integer column to store a timestamp for comparison purposes. In fact, it doesn’t actually need the timestamp to represent an absolute or even a relative point in time – all it cares about is that the if the function is called twice on 2 different hosts that the 2nd call will always …

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Once upon a timestamp(milliseconds)….
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Once upon a time`stamp`, in a `data`base far far away, someone filed a bug named: `Microseconds precision is not retained by TIME, DATETIME, and TIMESTAMP field types.` – Bug Number 8523. This was the beginning of 2005, yet now that we are approaching the end of 2009, after 4.5 years, many (including myself) are still asking for this.

In fairness sake, MySQL have indeed supplied a way to retain milli and micro seconds in a decimal field `DECIMAL(17,3)`, and it is also queryable as if it were a timestamp BUT why isn’t it possible to store in a `DATETIME` or `TIMESTAMP` field? Why can’t we run a ’select now()’ or ’select curtime()’ …

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Showing entries 1 to 10 of 13 3 Older Entries

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