I am trying to convert dates in the format mm/dd/yyyy to the standard date format yyyy-mm-dd using the STR_TO_DATE function. Some fields in my date column are null and some contain a date.
For instance, 8/22/2011 should become 2011-8-22.
When I select my date column, it looks like this:
8/22/2011
8/10/2010
5/12/2012
etc.
I tried using the code
UPDATE table SET date = STR_TO_DATE(date, '%m/%d/%Y')
which filled the column with NULL values. Also tried
UPDATE table SET date = STR_TO_DATE(#date, '%m/%d/%Y')
with same result, although this time I did not get a warning message.
The first one is correct:
UPDATE table SET date = STR_TO_DATE(date, '%m/%d/%Y')
But if the date is not valid (not in %m/%d/%Y format) then it returns NULL
Try executing and then showing warnings. It tells you what is wrong:
UPDATE table SET date = STR_TO_DATE(date, '%m/%d/%Y');
SHOW WARNINGS;
Maybe some dates are not in format %m/%d/%Y (posibly %d/%m/%Y)
Related
I have a database, with around 500k rows, I don't know why but instead of using "Date" type on the column it uses "varchar". Now the date has a format - 01/02/2021 07:08:49 AM
My question is how should an SQL query look to delete this kind of "old" date rows from the table? Or in another hand how should I convert the column without losing the data and holding the same format to a Date type column?
I tried deleting with something like this:
DELETE FROM `visited` WHERE LEFT(`last_visit_date`, 2) != '01' OR LEFT(`last_visit_date`, 2) != '12';
However, this didn't fully clean the table.
Any help would be appreciated.
You may use STR_TO_DATE in your delete query to convert the text dates to bona fide dates:
DELETE
FROM visited
WHERE
STR_TO_DATE(last_visit_date, '%d/%m/%Y %h:%i:%s %p') < '2020-11-01';
Note that if your text dates actually have month before day, then use this call to STR_TO_DATE:
STR_TO_DATE(last_visit_date, '%m/%d/%Y %h:%i:%s %p')
If you don't want to lose the dates with the wrong format, you can update the table:
UPDATE visited
SET last_visit_date = STR_TO_DATE(last_visit_date, '%d/%c/%Y %r')
WHERE last_visit_date LIKE '__/__/____ __:__:__ __';
and change the data type of the column to DATETIME (if all the other values of last_visit_date are valid datetimes):
ALTER TABLE visited MODIFY last_visit_date DATETIME;
See a simplified demo.
The default date format in my SQL is : '2019-05-06'
and its fine but when i insert date to my table i want this format 2019-5-6 not the above format
It means month and day must be start 1 to 30 not 01 to 31.Is there any way to change default format in my sql?
You seem to be looking for the MySQL STR_TO_DATE function :
It takes a string str and a format string format. STR_TO_DATE() returns a DATETIME value if the format string contains both date and time parts, or a DATE or TIME value if the string contains only date or time parts.
So if the date coming out of your application is like '2019-5-6', to convert it to a MySQL date you need :
STR_TO_DATE('2019-5-6', '%Y-%c-%e')
In an INSERT statement :
INSERT INTO mytable VALUES(1, STR_TO_DATE('2019-5-6', '%Y-%c-%e'));
Tip :
%Y : Year as a numeric, 4-digit value
%c : numeric month name (0 to 12)
%e: day of the month as a numeric value (0 to 31)
The default way to store a date in a MySQL database is by using DATE. The proper format of a DATE is: YYYY-MM-DD. If you try to enter a date in a format other than the Year-Month-Day format, it might work but it won't be storing the dates as you expect.
In order to run a MySQL Insert command and add the current date into your table you can use MySQL's built-in function CURDATE() in your query.
An example of how to Insert a Date in MySQL using CURDATE
$query_auto = "INSERT INTO tablename (col_name, col_date) VALUE ('DATE: Auto CURDATE()', CURDATE() )";
Also, you can run a query to set the date manually
An example of how to Insert a Date in MySQL manually
$query_manual = "INSERT INTO tablename (col_name, col_date) VALUES ('DATE: Manual Date', '2008-7-04')";
It is recommended to do the date formatting when doing a query, like so:
SELECT DATE_FORMAT(BirthDate, "%W %M %e %Y") FROM Employees;
You can find more examples of formatting the date here:
https://www.w3schools.com/sql/func_mysql_date_format.asp
In mysql database,column name created.This "created " column is text datatype,I need to change this to datetime.Now this column have so many datas.Is it possible to convert it or?
Database look like
created
18-11-15 18:21:25
Expecting ouput is
created
2018-11-15 18:21:25
When am doing
ALTER TABLE invoices MODIFY created datetime
This query giving wrong data.its converting from 15-09-18 03:03:43 to 2015-09-18 03:03:43
If the original data is not in MySQL Datetime format (YYYY-MM-DD HH:MM:SS), you cannot just change the column datatype from Varchar/Text to Date/Datetime. Otherwise, there will be an irreparable Data loss.
This will be a multi-step process. You will first need to convert the date string to MySQL date format (YYYY-MM-DD HH:MM:SS). We can use STR_TO_DATE() function for this.
Your sample date string (18-11-15 18:21:25) is basically in %y-%m-%d %T format. Following format specifiers can be used:
%d Day of the month as a numeric value (01 to 31)
%m Month name as a numeric value (00 to 12)
%y Year as a numeric, 2-digit value
%T Time in 24 hour format (hh:mm:ss)
The query to update the date would look as follows:
UPDATE invoices
SET created = STR_TO_DATE(created, '%y-%m-%d %T');
Now, you can use Alter Table to change the data type from Text type to Datetime.
ALTER TABLE invoices
MODIFY COLUMN created datetime;
The best thing to do here is to not store your dates as text. Assuming you have already done this, we can cope by calling STR_TO_DATE to generate a bona fide date:
SELECT
STR_TO_DATE(created, '%y-%m-%d %h:%i:%s') AS created_out
FROM yourTable;
Since the output you expect is standard date output, we can stop here and avoid also calling DATE_FORMAT to generate a different output.
you want to convert output or database records ? for second you can use sql query :
UPDATE 'table_name' SET 'created' = CONCAT('20', 'created')
You will need first to interchange the day with the year in the created column, as follows:
UPDATE invoices
SET created = CONCAT(SUBSTR(created, 7, 2), '-', SUBSTR(created, 4, 2), '-', SUBSTR(created, 1, 2));
Then, you convert the column to DATETIME, as follows:
ALTER TABLE invoices MODIFY created DATETIME;
Hope this helps.
How to convert a timestamp into custom formated string with timezone in MySQL?
This is how I am selecting the timestamp right now. Its correctly formated, but lacks timezone. updated is the name of the timestamp field.
SELECT DATE_FORMAT(updated, '%e.%c.%Y %T') AS updated FROM table;
returns strings like this:
29.1.2015 12:43:16
Then I tried adding timezone like this, but I am getting NULLs as return values.
SELECT DATE_FORMAT(CONVERT_TZ(updated, 'GMT', 'Europe/Helsinki'), '%e.%c.%Y %T') AS updated FROM table;
i use 1383123123 instead timestamp field
Select FROM_UNIXTIME(1383123123);
the result is '2013-10-30 10:52:03'
Select CONVERT_TZ(FROM_UNIXTIME(1383123123), '+00:00', '+02:00')
the result is '2013-10-30 12:52:03'
'Europe/Helsinki' time zone means "gmt+2"
I have a table which is populated with data from an external source. The problem is I am getting two different format of dates for the same column, there are some records in '%Y-%m-%d %H:%i' format and other in '%Y-%d-%m %H:%i%s' format and they are all VARCHAR type.
I know how to convert a string type date field to a date/datetime field but how do I handle discrepancies in the way the dates are coming? Is it possible to Update dates on the basis of their individual format, so that I can apply a WHERE condition for updates to take place ONLY WHERE date_field is of '%Y-%m-%d %H:%i' format, and then another query to make updates for date field in '%Y-%d-%m %H:%i%s' format?
Right now when I try updating the tables with a common query I get error for the fields which donot match the format:
UPDATE my_table
SET my_date_field = STR_TO_DATE(my_date_field,'%Y-%m-%d %H:%i:%s');
RESPONSE: Error Code: 1411. Incorrect datetime value: '10-22-12 15:00' for function str_to_date
UPDATE my_table
SET my_date_field = STR_TO_DATE(my_date_field,'%Y-%d-%m %H:%i');
RESPONSE: Error Code: 1292. Truncated incorrect datetime value: '2010-01-01 00:00:00'
for this value 10-22-12 15:00 you should use, %y-%d-%m %H:%i
while for 2010-01-01 00:00:00, it should be %Y-%m-%d %H:%i:%s
so your query will use CASE
UPDATE my_table
SET my_date_field = (CASE WHEN CHAR_LENGTH(my_date_field) = 14
THEN STR_TO_DATE(my_date_field,'%y-%d-%m %H:%i')
ELSE STR_TO_DATE(my_date_field,'%Y-%m-%d %H:%i:%s')
END)
See SQLFiddle Demo
Other Source
DATE Formats
you can not update like that because if there is data in that column and it is of different type then you can not update table column so you should delete the column or make a procedure for that in that you can check and the replace or update table.