How to use format function to update a column - sql

I have a column of date datatype (the column name is orderdate). I want to convert it to 'fa' culture using format function.
I wrote different kind of query such as below, but I got different conversion error.
UPDATE [dbo].[orderstest]
SET [OrderDate] = CAST(FORMAT([OrderDate], 'yyyy/MM/dd', 'fa') AS DATETIME)

try this:
UPDATE [dbo].[orderstest]
SET [OrderDate] = CAST(FORMAT([OrderDate], 'yyyy/MM/dd', 'fa-ir') AS DATETIME)
But this is not the trust way because you are converting the original date to a Persian and then converting it to date time!
I suggest saving all dates as us-date and everywhere you want to get it, convert to Persian

Related

SQL - Date format conversion issue (AUTO to 'MM/DD/YYYY')

In Snowflake, I have a column in a created table called "Date1", that has dates formatted as AUTO (ex. 2022-06-17). I am trying to query that column, but need the date formatted as 'MM/DD/YYYY', yet everything I've tried returns an error of some kind.
When I try date(Date1, 'MM/DD/YYYY) the error says that it can't parse 2022-06-17 for MM/DD/YYYY. When I try to_date(Date1 [MM/DD/YYYY]) or try_to_date(Date1 [MM/DD/YYYY]) the error says it doesn't recognize MM.
Any thoughts?
If you're trying to display the date using a specific format, you're converting to a varchar rather than a date:
select to_varchar(current_date, 'MM/DD/YYYY');
If you're trying to compare a column with a date to a formatted string in MM/DD/YYYY format then:
select current_date = try_to_date('08/04/2022', 'MM/DD/YYYY');
You should try to provide correct format to match 2022-06-17 literal:
SELECT TRY_TO_DATE(Date1, 'YYYY-MM-DD')
FROM tab_name;
Your column is already of type DATE. TO_DATE() and TRY_TO_DATE() convert non-date formats (string, integer) to a DATE type. They are not a means to format your DATE for presentation.
Date data type and presentation format are indepent.
You can alter your session to change the default display format of a date, but the underlying representation in the database remains the same.
alter session set DATE_INPUT_FORMAT='MM/DD/YYYY';
alter session set DATE_OUTPUT_FORMAT='MM/DD/YYYY';
select <col_name> from table; -- Now will show as MM/DD/YYYY for date columns

I have an oracle table which has date in dd-mm-yyyy and dd/mm/yyyy format in same field. Now i have to convert into one common format

I have an oracle table which has date in dd-mm-yyyy and dd/mm/yyyy format in same field. Now i have to convert into one common format.
Please suggest how to approach this?
I did tried but it is failing as it is failing due to invalid month.
Is there a way i can first identify what format the date is and then based on case statement i might convert.
or something easy way? Please
I trust you've learnt your lesson and you're now going to store these dates in the date data type.
Your two different date formats actually aren't important, Oracle already is a little over accepting when it comes to separating characters.
e.g
to_date('01/01/1900','dd-mm-yyyy')
Does not error
I did tried but it is failing as it is failing due to invalid month.
Your error is coming because you've allowed a value that doesn't match either of those formats into your string column.
If you are on version 12.2 at least (which you should be in 2020) then you can use the validate_conversion function to identify rows that don't convert to a date with your format (https://docs.oracle.com/en/database/oracle/oracle-database/12.2/sqlrf/VALIDATE_CONVERSION.html#GUID-DC485EEB-CB6D-42EF-97AA-4487884CB2CD)
select string_column
from my_table
where validate_conversion(string_column AS DATE,'dd/mm/yyyy') = 0
The other additional helper we got in 12.2 was the on conversion error clause of to_date. So you can do.
alter table my_table add my_date date;
update my_table set my_date = to_date(my_string default null on conversion error,'dd/mm/yyyy');
If you are confident that there is no other format than those two, a simple approach is replace():
update mytable set mystring = replace(mystring, '/', '-');
This turns all dates to format dd-mm-yyyy.
I would suggest taking a step forward and convert these strings to a date column.
alter table mytable add mydate date;
update mytable set mydate = to_date(replace(mystring, '/', '-'), 'dd-mm-yyyy');
This will fail if invalid date strings are met. I tend to consider that a good thing, since it clearly signals that this a problem with the data. If you want to avoid that, you can use on conversion error, available starting Oracle 12:
to_date(
replace(mystring, '/', '-') default null on conversion error,
'dd-mm-yyyy'
)
Then you can remove the string column, which is no longer needed.

Date format value not updating from previous format to new format after update

When I update a column from a table with a date format of MMM DD,YYYY to a new format. The format doesn't change to the desired format which is YYYY-MM-DD HH:MM:SS. Even when update different value like GETDATE(). The date will change but the format will remain the same.
Current value & format from column the type is varchar
DueDate
Jun 27 2020 12:00AM
Desired format
DueDate
2020-06-27 00:00:00.000
Update statement
update TableName
set
DueDate = CAST([DueDate] AS smalldatetime),
LastSyncDateTime = GETDATE()
where CaseGuid = 'DA2CE6A1-0394-463E-8E8D-962F3A24ADC8'
There is a huge confusion between "Date displaying format" and "Date storing format". The VERY short explanation is that what you mentioned is only a client side displaying format, while SQL Server have specific format which is used for storing dates (remember that the server stores zero and one only).
You can insert dates to a table using different styles (the official name for the displaying format is STYLE), and you can present the dates in the client side using different style, but it will always be stored the same from the "SQL Server point of view" according to the DATE type which is used.
In order to solve your original needs, all that you needed to do is to provide the server the information about the style which you use in the client side (in the query). This is done by using explicit CONVERT with the third parameter, which is the STYLE.
For example if you use in the client side an Israeli format like dd/MM/yyyy, then you should use CONVERT(DATE, '27/02/2021', 103).
For more information on different STYLEs you can check this documentation.
Note: If you want to display the dates in specific format which is not covered by the existing STYLEs then you can use the function FORMAT() in your query. This function is fully flexible to return the data in your specific format. Remember that this function returns the data as string and it will not be date anymore.
For example, let's say that I want to use the format: "Day:dd,Month:MM,Year:yyyy". So if the date is '27/02/2021' then I expect to get "Day:27,Month:02,Year:2021". In this case use below:
DECLARE #D DATE
SET #D = CONVERT(DATE, '27/02/2021', 103) -- convert string to date for storing
select FORMAT(#D, 'Day:dd, Month:MM, Year:yyyy') -- convert date to string for displaying
Solution use the format function
update TableName
set
DueDate = FORMAT (CAST([DueDate] AS smalldatetime),'yyyy-MM-dd HH:mm:ss'),
LastSyncDateTime = GETDATE()
where CaseGuid = 'DA2CE6A1-0394-463E-8E8D-962F3A24ADC8'
https://www.sqlshack.com/a-comprehensive-guide-to-the-sql-format-function/

Convert from varchar into date in SQL Server

This looks easy solution but I can't seem to figure out as to why this is not working for me. I have a column that has data like this:
DateField
----------
12/16/2016
11/06/2016
All I want to do is to convert from varchar into a date column, but I am getting this error:
Conversion failed when converting date and/or time from character string.
Here is my simple query:
select convert (date, DateField) as convertedField
from myTable
Nothing wrong with the two examples you have given. There are some bad dates in your table which cannot be converted to date.
Use TRY_CONVERT function for bad dates it will return NULL
select TRY_Convert(date,DateField)
From myTable
You should always store dates in DATE/DATETIME datatype.
If you want to see the records which cannot be converted to date then
select DateField
From myTable
Where TRY_Convert(date,DateField) IS NULL
If working with a specific date format like mm/dd/yyyy You can specify it in Convert() function like the following
CONVERT(DATETIME,DATAFIELD,101)
If it still is not working, use TRY_CONVERT() to get which rows are throwing this exception:
SELECT *
FROM TBL
WHERE TRY_CONVERT(DATETIME, DATAFIELD, 101) IS NULL
This will return rows that cannot be converted
TRY_CONVERT() will return NULL if conversion failed
Read more about DateTime formats here:
SQL Server CONVERT() Function tutorial
Read TRY_CONVERT MSDN Article
You need to specify the format of date time while formatting. The date in your table is currently in U.S format so you should pass the third argument 101 in your convert function.
SELECT CONVERT(date,[DateField],101) FROM myTable;
Working Fiddle here http://rextester.com/NYKR49788
More info about date time style here: https://msdn.microsoft.com/en-us/library/ms187928.aspx

Convert Date Against Where Clause

I have Following dummy table with data:
ACID srno date(mm/dd/yyyy) name
3 1 04/12/2010 mahesh
3 2 04/12/2010 mahendra
Now if I try with Following SQL Transact:
select srno from dummy
where name = 'mahesh'
and date= convert(datetime,'12/04/2010',101) –- I have date in dd/MM/yyyy Format
and ACID=3
It’s Not returning the srno of the table. That means Date is not execute convert statement as above
What’s the reason?
Try using style 103 instead of 101.
select srno from dummy
where name = 'mahesh'
and date= convert(datetime,'12/04/2010',103) –- I have date in dd/MM/yyyy Format
and ACID=3
If you convert 12/04/2010 using format 101, you get date "December 4, 2010", which is not in your database. Use format 103 to convert a date in format dd/mm/yyyy to DateTime.
The database stores dates using the DateTime type which is format-agnostic. It does have a default format for string conversions, which seems to be mm/dd/yyyy (101) on your database.
However, when you convert a string to add it to your table, you want to specify the format of your input string, in your example dd/mm/yyyy (103).
Take a look at the MSDN article for CAST and CONVERT which details all format styles that you can use with dates.
To be honest, if you want to specify a DATE LITERAL in SQL Server, please stick with the simplest YYYYMMDD format, e.g.
and dummy.date = '20100412'
It is robust and works for all regional, user language and dateformat settings. This assumes the other side of the comparison is already a date column. Even if you had to CAST it, using this format you don't need to specify a format
and dummy.date = cast('20100412' as datetime)