I'm trying to select with reference to one column changing its time in MySQL, but I don't know how.
How will I do it?
Example:
Time original: 2015-07-20 22:10:52
Updated: 2015-07-20 23:59:59
You can use timestamp to join the current timestamp's date with the time you want to set:
UPDATE mytable
SET mytimestamp = TIMESTAMP(DATE(mytimestamp), '23:59:59')
To update with no reference to previous column value, it's no different from other columns. To update with it, and based on certain part (second, month, year, whatever), you can use DATE_ADD or DATE_SUB function. Any other function in the same page might be useful, too, depending on your needs.
It doesn't matter what type of column you have, your table can be modified with a standard UPDATE statement.
You can also use the some special time/date functions to help you get the right format.
UPDATE mytable SET mytimestamp = mytimestamp::date + '23:59:59'::time;
it should work.
Related
I have a table and have a column name as dates, data type is varchar(50).
like this:
dates
-------
16/06/2017
25/05/2017
03/06/2017
17/06/2017
03/06/2017
12/06/2017
05/06/2017
06/06/2017
15/06/2017
13/06/2017
29/04/2017
21/05/2017
I tried this:
select s.date
from add_vehicle a
left join services s
ON a.vid=s.vid
where date BETWEEN '01/04/2017' AND '19/06/2017'
I only get 6th month data only.
If I change the '19/06/2017' to '30/06/2017' then I get balance results.
What is the problem? How to fix it?
Guide me please.
Note:sqlfiddle not working
Fix your data! Databases support date/time data types for a reason. That is because you should use them. In your case, you can do:
UPDATE t
SET dates = date_format(str_to_date(date, '%d-%m-%Y'), '%Y-%m-%d');
Then, alter the data type:
ALTER TABLE t MODIFY dates date;
Voila! Your code will start working.
Don't write overly complicated queries to get around a problem in the data. Fix the data.
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).
I know how using STR_TO_DATE(str,fmt); will change the format of a specific string, but if I have a column of all different dates in a text format (ex. 1/11/2016, 1/25/2016, 6/27/2015...) how do I convert all of the data in the column to DATE format? From everything I'm reading, it seems you need to provide the exact value to be converted each time.
You can use multiple ifnull fuction for this.
select ifnull(STR_TO_DATE(a,'%Y-%m-%d'),sTR_TO_DATE(a,'%Y-%d-%m')) from [YourTable];
update [YourTable] set timestamp=ifnull(STR_TO_DATE([Colum],'%Y-%m-%d'),sTR_TO_DATE(a,'%Y-%d-%m')) ;
Hope this helps.
Thanks Mark B.
str_to_date(yourfield, '%d/%m/%Y'), done. you can use fields in a record as part of the update query, e.g. update foo set bar=bar+1 is completely legitimate/valid.
So I used:
update [My_Table]
set Create_Date = str_to_date(Create_Date, '%d/%m/%Y')
Help! One column in my database is for dates. All of my dates are unfortunately in the String form (YYYY.MM.DD). I have a MASSIVE database (300+GB) so ideally would like to avoid transformations.
Is there a way I can select rows for dates in between YYYY.MM.DD and YYYY.MM.DD? What would the script look like?
Thank you!
If the months and days are stored with leading zeroes, the BETWEEN operator will work as expected. So will ORDER BY.
create table your_table (
date_value varchar(10) not null
);
insert into your_table values
('2013.01.01'), ('2013.01.13'), ('2013.01.30'), ('2013.01.31'),
('2013.02.01'), ('2013.02.13'), ('2013.02.28'), ('2013.02.31'),
('2013.03.01'), ('2013.03.15'), ('2013.03.30'), ('2013.03.31');
select date_value
from your_table
where date_value between '2013.01.01' and '2013-01-31'
order by date_value;
2013.01.01
2013.01.13
2013.01.30
One of the main problems with your structure is that you lose type safety. Look at this query.
select date_value
from your_table
where date_value between '2013.02.01' and '2013.02.31'
order by date_value;
2013.02.01
2013.02.13
2013.02.28
2013.02.31
If you'd used a column of type date or datetime or timestamp, the dbms would not have allowed inserting the values '2013.02.31', because that's not a value in the domain of date. It is a value in the domain of varchar. (And so is "Arrrrgh!", unless you've got a CHECK constraint on that column that severely restricts the acceptable values.)
Not good solution, but works (cost much performance).
You have formated date in order year, month, day (good order to compare strings, without transformation to datetime), so you can try
SELECT * FROM Table WHERE StringDate > '2013.07.10' AND StringDate < '2013.07.14'
It returns bad results if there are dates before year 1000 without leading zero ('999.07.14').
But I dont know how it works on big database.
SQL Fiddle
Between in SQL is inclusive of both bounds. If that is what you want, you can just use between:
where col between 'YYYY.MM.DD' and 'YYYY.MM.DD'
Where the two constants are whatever values you are looking for.
If you have an index on the column, then between (as well as >, >=, and so on) will use the index. You do not need to transform the values. If your constants are dates of one form or another, then you can use date_format() to create a string in the right format. For instance, to get dates within the past week:
where col >= date_format(adddate(now(), -7), '%Y.%m.%d')
I have a 300.000 rows table; one of the columns is a varchar() but it really contains a date xx/xx/xxxx or x/x/xxxx or similar. But executing the following test yields an error:
SELECT CAST(MyDate as Datetime) FROM MyTable
The problem is that it doesn’t tell me in which row…
I have executed a series of “manual” updates by trial an error and performed simple updates to fix those, but there’s got to be some weird values that need to either be deleted or fixed.
For example I performed a simple test that fixed about 40 rows:
UPDATE MyTable SET MyDate = REPLACE(MyDate, '/000','/200') FROM MyTable WHERE MyDate like ('%/000%’)
UPDATE MyTable SET MyDate = REPLACE(MyDate, '/190','/199') FROM MyTable WHERE MyDate like ('%/190%’)
This fixed quite a few weird rows that had dates like 01/01/0003 and such. (Dates range from 1998 to 2010).
However, I’d like to know which rows are failing in the above select.
What would be the best way to print those so I can either delete them, edit them or see what to do? Thanks.
SELECT
*
FROM
MyTable
WHERE
ISDATE(MyDate) = 0
From the ISDATE(Transact-SQL) documentation ISDATE(...)
Returns 1 if the expression is a valid datetime value; otherwise, 0.
ISDATE returns 0 if the expression is a datetime2 value.
Did you try the ISDATE function?
Careful with IsDate. I have 1 bad record in a table of thousands. It says 8201-11-30 is a valid date. IsDate should have a YEAR limitation.
ISDATE doesn't seem to be working always.
the following returns 1 in SQL server 2008 R2
Select ISDATE('04- December 20')
But trying to cast the same value to date will fail.
Select cast('04- December 20' as date)
Conversion failed when converting date and/or time from character string.