The dates in my database are stored as dd/mm/YYYY
How can I construct a simple mySQL query to pull dates within a certain range:
e.g.
SELECT * FROM metric WHERE date BETWEEN '31/01/2016' AND '01/02/2017'
You can use str_to_date but remember that now the server can't use index on the date column if any.
select *
from metric
where str_to_date(date,'%d/%m/%Y') between '2016-01-31'
and '2017-02-01'
It's better to store the date as date or if string then in standard format yyyy-mm-dd.
You should do the following:
Update all the columns that hold a date as a string to a date column
UPDATE metric SET `dateColumn` = str_to_date(`dateColumn`,'%d/%m/%Y');
Alter table
ALTER TABLE metric MODIFY `dateColumn` DATE;
Modify your code to insert valid dates to mysql
Use built in mysql date functions for your task
SELECT * FROM metric WHERE date BETWEEN '2016-01-31' AND '2017-02-01'
Related
I have the following code, with the column SaleDate in a datetime format, and I am trying to update it in the table to a date datatype instead
UPDATE nashhousing
SET SaleDate = CONVERT(SaleDate, DATE)
and
UPDATE nashhousing
SET SaleDate = CAST(SaleDate AS DATE)
I've tried both cast and convert, but neither modifies the table, does anyone know what's wrong?
You need to ALTER the table structure for that:
ALTER TABLE nashhousing Modify column SaleDate date
This will try to convert the date strings into real dates. Check the data afterwards if it succeeded. If not, you need to change the strings first to the right format. The default date format that always works is YYYY-MM-DD.
Of course if this is live data you should test that with a backup table first.
In my database the column type is varchar(30) which stores date (24/02/2018), having multiple records.
i want the maximum date e.g i have 10/01/2016, 20/03/2017, 24/02/2018.
I am using the below query:
SELECT MAX(receipt_date) as rd FROM tblname
which returns me 10/01/2016 which is wrong.
i also tried to convert it to date format. but failed. mysql gives me syntax error.
SELECT CONVERT(varchar, mycolumn, 105) FROM tblname
but failed.
This is what I'd do:
ALTER TABLE tblname ADD COLUMN receipt_date2 DATE;
UPDATE tblname SET receipt_date2 = STR_TO_DATE(receipt_date, '%d/%m/%Y');
ALTER TABLE tblname DROP COLUMN receipt_date,
CHANGE receipt_date2 receipt_date DATE;
SELECT MAX(receipt_date) AS rd FROM tblname;
You can't use dates effectively in MySQL if you store than as VARCHAR in dd-mm-yyyy format. You should use a DATE data type. MySQL's DATE data type stores dates in yyyy-mm-dd format only. This way it can search for MAX() easily, it can sort them, it can do date arithmetic.
How can i use the alter query to change a DATE format in mysql
for example
ALTER table userdata ADD column DateofBirth DATE SET = '%d-%m-%Y';
I tried this and it didnt work.
If your dates are stored in column with type DATE. You can set date format in SELECT query:
SELECT DATE_FORMAT(DateofBirth ,'%d-%m-%Y') AS DateofBirth FROM userdata;
There is no "date format" specified with the DATE datatype. It's not possible to specify a format with the column definition.
MySQL does provide a couple of useful functions... STR_TO_DATE and DATE_FORMAT that convert between DATE and string representations, in a variety of formats.
Reference: http://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_date-format
If am not wrong, you need a update statement
Update userdata set DateofBirth = DATE_FORMAT(DateofBirth ,'%d-%m-%Y')
But it is better to store dates in DATE datatype
A very simple Insert statement with a topic and a date I would like to insert the date as a certain format "MM/DD/YY" Don't know if it's possible or not?
$sql = "INSERT INTO Topic (Topic,date) VALUES ('$Topic',NOW())";
No, it is not possible using just NOW(). That format is not the standard date format for MySQL so you have to store it as a string. But that is a bad idea because you can use any of MySQL's date functions without first converting back into a valid date which is tedious.
Just store your dates in the date data type and then when you want to retrieve them use DATE_FORMAT() to transform them into MM/DD/YY format.
SELECT DATE_FORMAT(date, "%m/%d/%y") as date FROM ....
-- date is now in MM/DD/YY format
I have one column date1 which is varchar type
I want this column to date type.
I tried changing field but all date is converted to 0000-00-00.
format is dd-mm-yyyy but in varchar.
How can I convert the same date format but with date format using sql queries or similar but at database level ?
UPDATE `table`
SET `column` = str_to_date( `column`, '%d-%m-%Y' );
More about STR_TO_DATE function.
Since your column name is date1, you can replace column with date1 in the above syntax, and the code shall be:
UPDATE `table`
SET `date1` = str_to_date( `date1`, '%d-%m-%Y' );
The other answers here are risky, because if they go wrong you'll lose your data. A safer way to do this is to create a new field on your database with a DATE (or DATETIME if you need time as well) format, then to run a query like
UPDATE `table` SET `my_new_date_field` = STR_TO_DATE( `my_old_data_field`, '%d/%m/%Y');
In this way, if the %d/%m/%Y bit is wrong, you won't lose your data.
Once you're happy, you can delete the old data field and rename the new one.
use STR_TO_DATE Function of MySQL
FIRST you will need to update the value in date format.
UPDATE `tbl` SET `date1` = STR_TO_DATE(`date1`, '%d-%m-%Y') WHERE 1=1
THEN Convert the field to date.
Most importantly remember to insert date as Y-m-d format, after then.