SQL Date_Format Month Number to Month Name - mysql

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

Related

Mysql returns some records null in field of date as date have multiple format

I am trying to analyze order_Date column and column have multiple date format i want to convert all those date in same format which wull make be easier to analyze the order_date.
I am trying to analyze the order_date however this column have multiple date format 2019/07/15 and 1/13/2014
Howeever, while converting different format date with one format yyyy/mm/dd with query.
select date_format(order_date, '%y/%m/%d'),orderid from superstore;
it shows null values like this.
i have tried to use `CAST as well but it shows every single value as null.
select case when order_date like '%Y' then date_format(order_date, '%Y/%m/%d') else null end as newdate from superstore;
date_format funtion is used to format a date datatype you should use https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_str-to-date any null values returned by str_to_date either failed or started as null. You will need to examine these and adjust the str_to_date parameters appropriately. There is a catch though is 20/2/20 y/m/d or d/m/y (for example) and how can you differentiate month and day where both are <=12?
For example
drop table if exists t;
create table t
(dt varchar(10));
insert into t values
('1/1/2020'),('2020/1/12'),('12/12/12'),(null),('13-14-15');
select dt,
case when length(substring_index(dt,'/',-1)) = 4 then str_to_date(dt,'%d/%m/%Y')
when length(substring_index(dt,'/',1)) = 4 then str_to_date(dt,'%Y/%m/%d')
when length(substring_index(dt,'/',1)) = 2 then str_to_date(dt,'%y/%m/%d')
else str_to_date(dt,'%y/%m/%d')
end dateformatted
from t;
https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=553219f33ad9e9a4404fc4c0cb6571c9
note in no case can I identify month and day and sometimes year..

SQL STR_TO_DATE

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.

How can i do a count of two columns in mysql?

i want to do a count of two columns in mysql. One of the columns is a string but another is a date like 06/08/2017 and when i do my query i get 0 results.
SELECT count(*) FROM `castigos` WHERE inicio_normal=05/06/2017 AND cod_emplazamiento=1
I have entries of that data but its dont show me anything. Maybe the type of data in the date is wrong?
What should i do?
Add the date field to your select and group by it. Otherwise mysql extensions doesn't recognize you want to group by the date and will aggregrate all the results into 1 column. And since you are getting 0 count, you're where clause must not be working.
Your date format seems malformed. usually YYYY/MM/DD format (standard format);
or specify a format using SELECT STR_TO_DATE('17/09/2010','%d/%m/%Y');
MySQL retrieves and displays DATE values in 'YYYY-MM-DD' format. The supported range is '1000-01-01' to '9999-12-31'.
the below uses the implicit casting and default date format to convert the string date to a valid date.
SELECT inicio_normal, count(*)
FROM `castigos`
WHERE inicio_normal='2017/05/06'
AND cod_emplazamiento=1
GROUP BY inicio_normal
Otherwise its doing math and comparing that date to the number stored for the date.
Understand dates should be stored in a date datatype and when you query dates you're passing in a string that is being cast to a date datatype for comparison. So you need to use the standard format, or cast your string to a date so the db engine knows how to convert your format to a date.
Try this :
SELECT count(*) FROM `castigos` WHERE inicio_normal="05/06/2017" AND cod_emplazamiento=1 GROUP BY inicio_normal
WHERE inicio_normal=05/06/2017
If you divide 3 by 6 then by 2017 you get a very small value indeed. OTOH if you reformat this as a date (e.g. 20170605, if you gave us a European formatted date - dd/mm/yyyy) then your query will find the rows you showed us.

Database check condition with day,month,year columns

I have table that contains first three columns day, month, year. I have kept it separated instead of making single column date, because this table contains information about subscription analysis. So by keeping separated I can analyze data on daywise. Now I have situation where I want to reset few data. Example like I want to reset data which day, month, year comes between date 2008-01-01 and 2010-10-01. So how can I make where condition in mysql query for separated day, month and year columns?
Please try the following...
WHERE STR_TO_DATE( CONCAT( yearValue,
'-',
monthValue,
'-',
dayValue ) ) BETWEEN '2008-01-01' AND
'2010-10-01'
This clause uses the CONCAT() function to form a string representation of the date being examined, then the STR_TO_DATE() function to convert that string to a DATE value which is then compared to the range specified.
If you have any questions or comments, then please feel free to post a Comment accordingly.
Further Reading
https://dev.mysql.com/doc/refman/5.7/en/comparison-operators.html#operator_between (on MySQL's BETWEEN operator)
https://dev.mysql.com/doc/refman/5.7/en/string-functions.html#function_concat (on MySQL's CONCAT() function)
https://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_str-to-date (on MySQL's STR_TO_DATE() function)
You should really store the value as a date. But you can still do what you want. Here is one way:
where year * 10000 + month * 100 + day between 20080101 and 20101001
Note that values are all integers. A date would be better because the query could take advantage of an index.
You may concatenate your three INT columns with the TO_CHAR function. The transform that into a date using TO_DATE, and then compare.
WHERE TO_DATE(TO_CHAR(year || month || day), 'yyyymmdd') BETWEEN '20080101' AND '20100101';

Retrieving all records based on a specific month in MySQL

my dates in my table are strings in the format:
"10/12/2009"
Now how would one get all the records from a month, lets say June (number "6" being provided)?
Check the MySQL function STR_TO_DATE.
You should not store dates as string, however. Use the type DATE.
The short answer to your question is that you can use the STR_TO_DATE and MONTH functions to 1) convert the string representation into a DATE, and 2) extract the month component from the date:
SELECT t.*
FROM mytable t
WHERE MONTH(STR_TO_DATE(t.dateasstringcol,'%M/%d/%Y')) = 6
(This is assuming here that by '10/12/2009', you are specifying Oct 12, and not Dec 10. You'd need to adjust the format string if that's not the case.)
Alternatively, if month is indeed the leading part of the date, you could do a simple string comparison, if the month is the leading component:
SELECT t.*
FROM mytable t
WHERE t.dateasstringcol LIKE '6/%'
OR t.dateasstringcol LIKE '06/%'
(You could eliminate one of those predicates, if you have an exact format specified for the striing value representing the date: either if month is always stored as two digits -OR- the month is never stored with a leading zero.)
If you are passing in an argument for the month, e.g. '6', then you could construct your statement something like this:
WHERE t.dateasstringcol LIKE '6' + '/%'
If month is the second component of the date, then you could use:
SELECT t.*
FROM mytable t
WHERE t.dateasstringcol LIKE '%/' + '6' + '/%'
OR t.dateasstringcol LIKE '%/' + '06' + /%'
NOTE:
All of the previous example queries will return rows for June of any year (2009, 2010, 2011)
You can extend those examples, and do something similar with the year, using the YEAR function in place of the MONTH function, or for string comparison
AND t.dateasstringcol LIKE '%/%/2011'
Normally, we'd extract rows for a particular month for a particular year, using a date range, for example:
SELECT t.*
FROM mytable t
WHERE MONTH(STR_TO_DATE(t.dateasstring,'%M/%d/%Y')) >= '2011-06-01'
AND MONTH(STR_TO_DATE(t.dateasstring,'%M/%d/%Y')) < '2011-07-01'
Of course, when the date value is stored as a DATE datatype rather than as a VARCHAR, this means we don't need the STR_TO_DATE and MONTH functions, we can specify a comparison to the native DATE column. This approach allows us to make use of an index on the date column, which can improve query performance on large tables.
SELECT t.*
FROM mytable t
WHERE t.realdatecol >= '2011-06-01'
AND t.realdatecol < '2011-07-01'
The STR_TO_DATE function is your friend here:
SELECT * FROM my_table
WHERE STR_TO_DATE('10/12/2009','%M/%d/%Y') >= '2012-06-01';
MONTH should help here if we want current month or particular month data. e.g:
$month = date('m'); OR particular month.
SELECT * FROM users WHERE MONTH(str_to_date("10/12/2009",'%e/%m/%Y')) = $month;