Using date separated colums to compare in mysql - mysql

I have three columns in a table to save a date, but now I need to compare those three columns as a date using the CONCAT and STR_TO_DATE function, but the comparision does not work, I don't see the error.
Query
SELECT * FROM mytable WHERE STR_TO_DATE(CONCAT(myyear,'-',mymonth,'-',myday),'%Y-%m-%d')>'2015-01-01'

For your example, why not just use this?
select *
from mytable
where myyear >= 2015

Related

Mysql selecting unique values in date type varchar

I have a column where the dates are type varchar. For example:
15-10-2018
16-10-2018
19-10-2018
23-10-2018
29-10-2018
8-11-2018
9-11-2018
10-11-2018
12-11-2018
when I consult with the following query
SELECT DISTINCT date FROM `test` WHERE date BETWEEN '15-10-2018' and '9-11-2018'.
I have the right result.
15-10-2018
16-10-2018
19-10-2018
23-10-2018
29-10-2018
8-11-2018
9-11-2018
but if the query is:
SELECT DISTINCT date FROM `test` WHERE date BETWEEN '15-10-2018' and '10-11-2018'.
or
SELECT DISTINCT date FROM `test` WHERE date BETWEEN '15-10-2018' and '12-11-2018'.
The answer I get is empty.
I think it's only validating the days in the sql.
I need to get the right dates.
I think the problem is the fact that the column is varchar, so it's comparing characters instead of a range of dates. I will recommend convert the column to date type and try again.
Alternative if you cannot change the type of the column you could cast it to date format like this:
SELECT DISTINCT `date` FROM `test` WHERE STR_TO_DATE(`date`,'%d-%m-%Y') BETWEEN '2018-10-15' AND '2018-11-10';
I tested with your data and it works. Of course this could put some extra effort on the database and will not use indexes.
You need to set the datatype to date and update your dates to be using date for a more reliable result. Once done you should be using the database format for the dates in your WHERE clause.
Try
SELECT DISTINCT date FROMtestWHERE date BETWEEN '2018-10-15' and '2018-11-10'

sql error using between operator with date between two dates

i have an events table having start date and end date I am trying retrieve all the records by giving a date that is between start and end dates.
eg :
SELECT *
FROM `events`
WHERE '2017-01-29' BETWEEN start_date='2017-01-28'
AND end_date='2017-01-31'
but response is syntax error can any one help me to finish the query
Just list the columns.
WHERE '2017-01-29' BETWEEN start_date AND end_date
The values come from the table, you don't put them into the query.
According to mysql documentation (https://dev.mysql.com/doc/refman/5.7/en/comparison-operators.html#operator_between) the syntax for BETWEN is
expr BETWEEN min AND max
it is not
expr BETWEEN blabla=min AND stuff=max
Also, it is rather pointless to be using constants in all three expressions, because in this case the result will be known in advance (either always TRUE or always FALSE) without having to consult the values in your table.
It is kind of hard to give you an example without knowing the structure of your table, but what you probably want is something like
WHERE '2017-01-29' BETWEEN start_date
AND end_date
(assuming start_date and end_date are columns in your table)
or something like
WHERE some_column BETWEEN '2017-01-28'
AND '2017-01-31'
(assuming some_column is a column in your table.)
I believe you're trying to find all the rows where a date is 2017-01-29, and so, your query could be:
SELECT *
FROM `events`
WHERE
date = '2017-01-29';
If, however, you want all rows with date between 2017-01-28 and 2017-01-31, then you could do:
SELECT *
FROM `events`
WHERE
date BETWEEN '2017-01-28' AND '2017-01-31';
Instead of putting 2017-01-29 before WHERE, put the name of the field you want to filter by date, such as EventDate (or whatever your field is named).

Filter dates stored as varchar in mysql

I am working with a MySQL database where dates are stored as varchar like this:
'2013-01-31' in column cl_223
I need to select only records from 2013 so I tried:
SELECT ..
FROM ....
Where cl_223 Like '2013'
But that does not seem to work.
Thanks for all help!
You must add % as a wildcard :
SELECT ..
FROM ....
WHERE cl_223 LIKE '2013%'
Storing a datettime value in a varchar column complicates some functionality on date time operations. But of course you can select your values writing such a query as follow
SELECT * FROM table_name WHERE cl_223 LIKE '2013%'
But if you don't have any performance issue you can convert the varchar column to a datetime value and write stronger typed query like this:
SELECT * FROM table_name WHERE STR_TO_DATE(cl_223,'%Y-%m-%d2') BETWEEN '2013-01-01' AND '2013-12-31'
But if you need a date time value as a date time in your process you'd better store it in a datetime column instead of a varchar column.
The query should be
SELECT ..
FROM ....
Where cl_223 Like '2013%'
However, the better solution would be to store the dates as DATE data types. If the dates in that column are always used in the format they're in now, the change would be backwards compatible. It would also allow for easier processing of the date values.

mysql select timestamps between a and b returning all or 0 timestamps

Tried this
select * from table where timestamp_field between 1330560000 and 1336170420
and this
select * from table where timestamp_field >=1330560000 and timestamp_field<=1336170420
both returning empty result set.
But this
select * from table where timestamp_field >= 1330560000
returns all the rows
To make things more absurd
select * from table where timestamp_field <= 1336170420
returns empty result set.
Of course, there exists timestamp values before, between and after 1336170420=4.may 2012. and 1330560000=1.march 2012.
Timestamp values are ok, at least phpmyadmin shows correct (human-readable) date-time values.
I created timestamps by parsing strings, with
UPDATE table SET timestamp_field = STR_TO_DATE(timestamp_string, '%d.%m.%Y')
Guess I'm missing something, but can't find what!?
MySQL expects date literals, not integer ones:
SELECT *
FROM table
WHERE DATE(timestamp_field) BETWEEN '2012-03-01' AND '2012-05-04'
To use integers (assuming that they are seconds since the UNIX epoch), first convert them using MySQL's FROM_UNIXTIME() function:
SELECT *
FROM table
WHERE timestamp_field BETWEEN FROM_UNIXTIME(1330560000)
AND FROM_UNIXTIME(1336170420)
Or else use UNIX_TIMESTAMP() to convert your column to its UNIX representation:
SELECT *
FROM table
WHERE UNIX_TIMESTAMP(timestamp_field) BETWEEN 1330560000 AND 1336170420
why not convert the timestamps from_unixtime(timestamp/1000) as dateTime while using your sql code? have you tried that?

How to select rows within some date range

I want to select rows that falls between some date range, I tried the following query but it didn't work.
SELECT * FROM tbl WHERE DATE_FORMAT(date_col, '%2011-%c-%e') BETWEEN '2011-11-28' AND '2011-12-5'
It doesn't seem like the BETWEEN keyword works on date. Please how do I get the results? Thanks
You don't need to use DATE_FORMAT if you want to compare dates.
SELECT *
FROM tbl
WHERE DATE(date_col) BETWEEN '2011-11-28' AND '2011-12-05'
Your code compares strings, assuming you use DATE_FORMAT(date_col, '%Y-%c-%e')
SELECT * FROM tbl WHERE DATE_FORMAT(date_col, '%Y-%m-%d') BETWEEN '2011-11-28' AND '2011-12-5'