I'm having trouble with the following code:
INSERT into `fun` ( funner)
SELECT YEAR(STR_TO_DATE(SUBSTRING(time,1,4), '%Y'))
FROM `orig`
returning the warning:
Incorrect datetime value: '1880' for function str_to_date
time is a varchar column in the table orig with the format yyyy/mm.
I want to extract the year section from this varchar and translate it into a year datatype using STR_TO_DATE
I would recommend using one of the usual date and time MySQL datatypes, instead of the rarely used YEAR datatype : DATE, DATETIME and TIMESTAMP.
If you want to turn your string to a date datatype, then :
STR_TO_DATE(my_column, '%Y/%m')
You can use the YEAR() function on this date, and it will return an integer value :
YEAR(STR_TO_DATE(my_column, '%Y/%m'))
Finally : if all you want is get the year from a date stored as string, then you can directly extract it the string using SUBSTR :
SUBSTR(my_column, 1, 4)
This returns a string (not an integer), that MySQL will implictely convert to a number when used in numeric context.
You can convert SUBSTRING(time,1,4) to integer:
SELECT CONVERT(SUBSTRING(time,1,4),UNSIGNED INTEGER) FROM orig
there is no need to convert it first to a date and then convert to integer.
I guess you need to return an integer value since you use the YEAR() function.
If not a simple SELECT SUBSTRING(time,1,4) FROM orig will do.
What does time look like? If year has the data type year, then you can insert a date into the column:
INSERT into `clean` (year)
SELECT DATE(CONCAT(SUBSTRING(time, 1, 4), '-01-01'))
FROM `orig` ;
I am not a fan of the year data type. You should just put the entire date into the column.
Related
How can a ISO datetime String timestamp be correctly parsed to time type column in mysql? I noticed the following:
select CAST('2013-09-05T10:10:02' as time) from mytable limit 1
Result incorrect:
00:20:13
select CAST(CAST('2013-09-05T10:10:02' as datetime) as time) from mytable limit 1
Result correct:
10:10:02
Why do I have to make a double CAST here to get the correct time? And more important: how is time parsing done property?
Because you have a string which you need to first cast it into date format.
If you cast it in time like below:
select CAST('2014-09-05T10:10:02' as time)
00:20:14
select CAST('2015-09-05T10:10:02' as time)
00:20:15
select CAST('2013' as time) --below casting string as time
00:20:13
If you monitor closely its treating it as string and getting year as time.
So you need to cast it datetime first then time.
select CAST(CAST('2013-09-05T10:10:02' as datetime) as time)
Basically when you try to convert something to a time that looks like an integer MySQL treats that as something in the form HHMMSS, so your 2013-09-05T10:10:02 becomes 00:20:13. To convert properly, the value needs to be a MySQL datetime, which you can do via CAST or you can use STR_TO_DATE to convert your date string to a MySQL date, then TIME to extract the time part of it:
SELECT TIME(STR_TO_DATE('2013-09-05T10:10:02', '%Y-%m-%dT%H:%i:%s'))
Output:
10:10:02
Demo on dbfiddle
I have created MySQL table :
CREATE TABLE EMP(
EMPID INTEGER NOT NULL (5),
SURNAME VARCHAR(25),
SAL INTEGER(5),
JON VARCHAR(25),
START_DATE DATE,
END_DATE DATE,
DEPNO INTEGER(5)
);
with following records:
INSERT INTO EMP
(EMPID,SURNAME,SALARY,JOB,START_DATE,END_DATE,DEPNO)
VALUES
('1','Vorosila','500000','COO','20150101',null,'1');
however I need to change date format from 2015 01 01 to 01 01 2015
Can anybody show me or tell me how to do that ?
THANK YOU IN ADVANCE
DATE values do not have a "format", they are objects that represent instants in time (or entire days, but still independent of formatting).
Formats are applied on input and output, so you just need to apply the correct format, which you can find in the MySQL manual, to the SELECT statement.
You cannot change the default date format in mysql.
I once hoped for the default date to be editable so I wouldn't have to jump through these hoops to get the date I actually wanted, mysql even has a date format system variable, but it is unused. Date Format Mysql - link
What you should really do is store it as the default format Year-Month-Date and then convert it on select.
The first thing I'd suggest is having your date columns as date types, which would give your dates the following format '2015-01-01'.
If you do this then you can use DATE_FORMAT - link - the second value in the DATE_FORMAT function allows you to customise the returned date, and there are many different thing you can do with this if you look at the link:
SELECT
DATE_FORMAT(`START_DATE`,'%d-%m-%Y')
AS `START_DATE`
FROM ...
The other option you have is to store your dates in the format that you already want as a char or varchar column.
HOWEVER, as should be obvious, this column will not be treated as storing dates, and so will not give you the correct comparisons in a where clause when using > < BETWEEN or the correct ordering in an order by clause. It is after all just a string of numbers in this case.
However you can then use STR_TO_DATE - link if you did need to use a where or order by on this column to change it back to a date within the query - in this case the second value is the custom format of your 'dates' in the column. Keep in mind with a where you will need to compare it with the correct mysql format as shown below:
SELECT
`START_DATE`
FROM table
WHERE STR_TO_DATE(`START_DATE`,'%d-%m-%Y') BETWEEN '2015-01-01' and '2016-01-01'
In MySQL you can change the format of a date using DATE_FORMAT method which is similar to to_char in Oracle.
DATE_FORMAT(SYSDATE(), '%DD-%MM-%YYYY');
For more information about specifiers check this thread http://www.sqlines.com/oracle-to-mysql/to_char_datetime
You can do what you probably want by creating a view and referring to that instead of the (underlying) table.
CREATE VIEW emp_view AS
SELECT empid,
surname,
sal,
jon,
date_format(start_date, '%d-%m-%Y') as start_date,
date_format(end_date, '%d-%m-%Y') as end_date,
depno
FROM emp;
Note that this changes the type of the date columns to varchar, so comparisons will no longer work as expected:
SELECT * FROM emp_view WHERE start_date > '01-12-1924'; // fails!
SELECT STR_TO_DATE('1.1.2000 0:00:00','%e.%c.%Y') will end up like 2000-01-01
but when I'm trying to do the same on column with values 1.1.2000 0:00:00 by running
SELECT
FirstDisplayedDate,
FirstDisplayedDate = STR_TO_DATE(FirstDisplayedDate,'%e.%c.%Y')
FROM product
I will get zero (NOT NULL!) in every row.
What am I doing wrong? :(
You get what you write: FirstDisplayedDate = STR_TO_DATE(FirstDisplayedDate,'%e.%c.%Y') compares FirstDisplayedDate with STR_TO_DATE(FirstDisplayedDate,'%e.%c.%Y') and if they are not equal returns zero. I think you want to use alias here so:
SELECT
FirstDisplayedDate,
STR_TO_DATE(FirstDisplayedDate,'%e.%c.%Y') AS FirstDisplayedDate2
FROM product
The STR_TO_DATE() function is the inverse of the DATE_FORMAT() 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.
If the date, time, or datetime value extracted from str is illegal, STR_TO_DATE() returns NULL and produces a warning.
The server scans str attempting to match format to it. The format string can contain literal characters and format specifiers beginning with %. Literal characters in format must match literally in str. Format specifiers in format must match a date or time part in str.
And, the reason to get zero is that unspecified date or time parts have a value of 0, so incompletely specified values in str produce a result with some or all parts set to 0, for example:
mysql> SELECT STR_TO_DATE('abc','abc');
-> '0000-00-00'
mysql> SELECT STR_TO_DATE('9','%m');
-> '0000-09-00'
mysql> SELECT STR_TO_DATE('9','%s');
-> '00:00:09'
Check in your query which format to use for date/time matching and make sure your database rows contains strings, which can be converted as dates and do not assign output values from the function to the same database field:
SELECT
FirstDisplayedDate,
STR_TO_DATE(FirstDisplayedDate,'%e.%c.%Y') AS Converted
FROM product
Here and here is more information how to use the function properly.
I have an issue in regards to trying to run a sql statement that returns the values of a column called month(of which I have defined as a varchar type, but only has integer values 1-12) as the associated month name. So, for example, the query would return a value of 1 as january. The issue I have is I am trying to use date_format
select date_format(month,'%M')from db.table name
but the values return as null. I was informed that the month values have to be a 'date' type in order for date_format to work. However, the values in this column 'month' are simply integers. So I run into the issue of not being able to assign the date type to the month columns because they're just integers and not correct format for dates? How could I take these single integers and return the month then?
Syntax
DATE_FORMAT(date,format)
Requires date as first param
Check out MySQL date function here:
http://www.w3schools.com/sql/sql_dates.asp
For this you can use this,
SELECT col as MonthNumber,
MONTHNAME(STR_TO_DATE(col, '%m')) as MonthName
FROM table_name
WHERE col <= 12
I'm having some troubles with converting varchar types to date types.
In SQL-server 2008 I'm having a table with different types of dates in type VARCHAR.
For example:
DDMMYYYY (05032013)<br/>
MMDDYYYY (03052013)<br/>
YYYYMMDD (20130305)<br/>
...
I have to convert these different string types to type "date" using a SQL-query.
Any suggestions how I can do this?
These are my records:
TYPE || FORMAT
____________________
DDMMYYYY||05032013
MMDDYYYY||03052013
YYYYMMDD||20130305
Try this
SELECT case
when type='DDMMYYYY' then convert(date,STUFF(STUFF('05032013',3,0,'-'),6,0,'-'),105)
when type='MMDDYYYY' then cast(substring('03052013',5,4)+'-'+substring('03052013',0,3)+'-'+substring('03052013',3,2) as date)
when type='YYYYMMDD' then cast(STUFF(STUFF('20130305',5,0,'-'),8,0,'-') as date)
end
If you can identify every row which date format is, you can convert them to date type. Otherwise i don't think that it will be completely correct. For example you can't implement logic for the following record - (03052013) can be 2013-05-03 or 2013-03-05.