quick question. In the DATETIME column in a MYSQL table, the format is, YYYY-MM-DD. So If i put insert today's date, as 2014-01-09, MYSQL will understand... But will it understand if i insert data like this?
YYYY/MM/DD or 2014/01/09
From the manual:
MySQL permits a “relaxed” format for values specified as strings, in which any punctuation character may be used as the delimiter between date parts or time parts.
So it would seem the answer is, yes.
mysql> select date('2016/06/16');
+--------------------+
| date('2016/06/16') |
+--------------------+
| 2016-06-16 |
+--------------------+
1 row in set (0.01 sec)
Related
I have a column dateofbirth_string which is a VARCHAR containing dates in format dd/mm/yyyy. I would like to convert these values into format DATE (yyyy-mm-dd) and place in field dateofbirth_date in the same row.
Note, some values in dateofbirth_string may be in a bad format e.g. 10/02/15 or 100215. For these values, they can be ignored and I will enter manually.
Thanks in advance for your help!
STR_TO_DATE is your goal.
SELECT STR_TO_DATE('22/04/2020', '%d/%c/%Y');
Sample
MariaDB [(none)]> SELECT STR_TO_DATE('22/04/2020', '%d/%c/%Y');
+---------------------------------------+
| STR_TO_DATE('22/04/2020', '%d/%c/%Y') |
+---------------------------------------+
| 2020-04-22 |
+---------------------------------------+
1 row in set (0.02 sec)
MariaDB [(none)]>
The actor table in the salika sample schema defines column last_update as a timestamp. I want to render that column using JSON_ARRAY in ISO8601 format. - First shouldn't that be the default rendering for JSON_ARRAY.
From reading the documentation and comments on this website and others it appears that the answer is to use FROM_UNXTIME with an output mask that generates ISO8601 Format.
Unfortunately FROM_UNIXTIME() appears to always return NULL on my database
mysql> select current_timestamp();
+---------------------+
| current_timestamp() |
+---------------------+
| 2018-10-03 17:15:03 |
+---------------------+
1 row in set (0.00 sec)
mysql> select from_unixTime(current_timestamp())
-> ;
+------------------------------------+
| from_unixTime(current_timestamp()) |
+------------------------------------+
| NULL |
+------------------------------------+
1 row in set (0.00 sec)
mysql>
I suspect this may be caused by the fact that I have not installed the timezone configuration files.. However when I try that I get...
mysql -u root -p****** sys <timezone_posix.sql
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 1146 (42S02) at line 1: Table 'sys.time_zone' doesn't exist
Sure I've missed something obvious here....
Just try this:
SELECT FROM_UNIXTIME(UNIX_TIMESTAMP(CURRENT_TIMESTAMP()));
As mysql doc says, function FROM_UNIXTIME(unix_timestamp[,format]) only accept parameter as a UNIX_TIMESTAMP, but not a TIMESTAMP.
Luckily, there's a function UNIX_TIMESTAMP(date) transforming various types such as DATE, TIMESTAMP and so on into UNIX_TIMESTAMP. So call UNIX_TIMESTAMP(date) first, and then `FROM_UNIXTIME(
This worked for me in the end...
select json_array("actor_id","first_name","last_name",DATE_FORMAT(convert_tz("last_update", ##session.time_zone, '+00:00'),'%Y-%m-%dT%T%fZ')) "json" from "sakila"."actor"
/
which gives
[
1,
"PENELOPE",
"GUINESS",
"2006-02-15T12:34:33000000Z"
],
[
2,
"NICK",
"WAHLBERG",
"2006-02-15T12:34:33000000Z"
]
I am trying to convert a TIMESTAMP to the DATETIME, DATE and TIME MySQL types using the FROM_UNIXTIME field. I noticed that the values for TIME and DATETIME fields have different time information on them.
Instead of the insert statement to the table, I am replacing it with a simple select statement that prints the values:
select FROM_UNIXTIME('1468561341') as timestamp_datetime,FROM_UNIXTIME('1468561341','%d/%m/%y') as timestamp_date, FROM_UNIXTIME('1468561341','%h:%m:%s %p') as timestamp_time
The results look like this:
timestamp_datetime: 2016-07-15 05:42:21.000000
timestamp_date 15/07/16
timestamp_time 05:07:21 AM
How can I get consistent time value in both these columns?
the issue is with letter m
it should be i
mysql> select FROM_UNIXTIME(1468561341) as timestamp_datetime,FROM_UNIXTIME(1468561341,'%d/%m/%y') as timestamp_date, FROM_UNIXTIME(1468561341,'%h:%i:%s %p') as timestamp_time;
+---------------------+----------------+----------------+
| timestamp_datetime | timestamp_date | timestamp_time |
+---------------------+----------------+----------------+
| 2016-07-15 05:42:21 | 15/07/16 | 05:42:21 AM |
+---------------------+----------------+----------------+
1 row in set (0.05 sec)
Your problem is that in your FROM_UNIXTIME you are essentially telling it to do
hours-months-seconds -AM/PM
But you want
hours-minutes-seconds -AM/PM
So change it to
FROM_UNIXTIME(1468561341,'%h:%i:%s %p')
instead.
Reference guide for all the time parameters and usage of time functions in MySQL here: https://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html
I need to treat a date field in mySQL as if it is a string. For the purposes of using the date in a LIKE statement:
select * from table where dob like some_string;
Doing this currently produces the following warning:
mysql> show warnings;
+---------+------+--------------------------------------------------------+
| Level | Code | Message |
+---------+------+--------------------------------------------------------+
| Warning | 1292 | Incorrect date value: '1492' for column 'dob' at row 1 |
+---------+------+--------------------------------------------------------+
1 row in set (0.00 sec)
I would use DATE_FORMAT to get a string representation of your DATE column:
SELECT
*
FROM
yourtable
WHERE
DATE_FORMAT(dob, '%Y-%m-%d') LIKE '1492%';
and use the pattern that suits your need best. You find the specifiers right in the linked manual page.
Note:
MySQL can't use an index for this kind of query, so it will be slow.
Use a cast
Select *
From Table
Where Cast(dob as nvarchar(20)) Like some_string;
using the date in a LIKE statement
No. Things that this approach does wrong:
Wastes CPU time converting dates to strings.
Wastes time doing string comparisons when integer comparisons could be done.
Throws away any index on dob that might otherwise make the query more efficient.
A better approach would be something like:
SELECT *
FROM table
WHERE dob BETWEEN '1492-01-01' AND '1492-12-31'
You will always want to do as few type conversions as possible and keep the table data as-is so that indexes are properly utilized.
I found some very strange mysql behavior.
If I run the following command:
mysql> select left(concat("A", "B®"), 3);
Then the output is as expected:
+-----------------------------+
| left(concat("A", "B®"), 3) |
+-----------------------------+
| AB® |
+-----------------------------+
1 row in set (0.00 sec)
However, if I change "A" with some number (1 in this case):
mysql> select left(concat(1, "B®"), 3);
The unicode character "®" becomes corrupted:
+---------------------------+
| left(concat(1, "B®"), 3) |
+---------------------------+
| 1B? |
+---------------------------+
1 row in set (0.00 sec)
Anybody knows how to explain this strange behavior and how to avoid it?
The example above is only a reproduction, in the real life it's a concat of numbers together with strings unknown ahead (not hard-coded strings).
Thanks a lot!
Mysql doesn't convert integer to strings literally. It converts number into the binary representation of it, which is not the same. "if the arguments include any binary strings, the result is a binary string. A numeric argument is converted to its equivalent binary string form; if you want to avoid that, you can use an explicit type cast, as in this example:
SELECT CONCAT(CAST(int_col AS CHAR), char_col);
Refer this for details.
I would also like to read from others if someone has different opinion.