The last argument of CONVERT seems to determine the format used for parsing. Consult MSDN docs for CONVERT.

111 - the one you are using is Japan yy/mm/dd.

I guess the one you are looking for is 103, that is dd/mm/yyyy.

So you should try:

 SELECT convert(datetime, '23/07/2009', 103)

SELECT CONVERT(char(10), GetDate(),126)

Limiting the size of the varchar chops of the hour portion that you don't want.

You don't need to convert the column as well. In fact, you better not convert the column, because using functions on columns prevents sql server from using any indexes that might help the query plan on that column. Also, you are converting a string to char(10) - better just convert it to date:

where date_column = convert(date, '2016-10-28', 126)

Also, if you are using a datetime data type and not date, you need to check that the datetime value is between the date you pass to the next date.

I understand your problem to be how to successfully convert the string into a DATE value. An undelimited string of integers is assumed to be Year-Month-Day order. (And, of course, I agree with the comments that dates should be stored in DATE data types in the database.)

Reviewing the MSDN CONVERT documentation does not show a built-in conversion for your string, but it is easy to work around.

http://msdn.microsoft.com/en-us/library/ms187928.aspx -- CAST and CONVERT

I changed the month to 8 to make it easier to double check. Using the CONVERT style option 3, you can do the following:

DECLARE @String VARCHAR(10);
DECLARE @DateValue DATE;
SET @String = '250809'; 

-- Convert your undelimited string DDMMYY into a DATE
-- First: Add / between the string parts.
SET @STRING = SUBSTRING(@String,1,2)+'/'+
     SUBSTRING(@String,3,2)+'/'+SUBSTRING(@String,5,2);
-- Second: Convert using STYLE 3 to get DD/MM/YY interpretation
SELECT @DateValue = CONVERT(Date, @String, 3);

-- Using the DATE 
-- Select the value in default Year-Month-Day
SELECT @DateValue AS DefaultFormat;    
-- Select the value formatted as dd/mm/yy
SELECT CONVERT(VARCHAR(20),@DateValue,3) AS [DD/MM/YY];

The results of the last two selects are:

DefaultFormat
-------------
2009-08-25

DD/MM/YY
--------
25/08/09

To get your DATE formatted in the way you want it, you have to insert the '/' delimiters then use the STYLE 3 in converting from the string to the DATE. (I am sure that there are other workarounds and conversion styles that would work as well.)

Likewise when displaying the DATE as you desire, you need to use STYLE 3

SELECT CONVERT(DATETIME,YourColumn,101) FROM YourTable

101 is mm/dd/yyyy format.

You zany backwards americans :)

To update your existing column

UPDATE YourTable 
SET YourNewColumn = CONVERT(DATETIME,YourOldColumn,101)

Since it appears you have invalid data, use this method to isolate it:

UPDATE YourTable 
SET YourNewColumn = CONVERT(DATETIME,YourOldColumn,101)
WHERE SomeTableKey BETWEEN ASmallCode AND ABiggerCode

Find a key in your table that you can use to divide up the data and try updating half the table... now halve it again and again until you find the offending data. Post the data here and we will come up with some code to allow for it.

Hi @Tim Mullady ,

would you please try

FORMAT(CONVERT(datetime, ColumnName, 101), 'MM/dd/yyyy')  

Thanks!

That task should be done by the next layer up in your software stack. SQL is a data repository, not a presentation system

You can do it with

CONVERT(VARCHAR(10), fmdate(), 101)

But you shouldn't

The error is happening because you (or whoever designed this table) have a bunch of dates in VARCHAR. Why are you (or whoever designed this table) storing dates as strings? Do you (or whoever designed this table) also store salary and prices and distances as strings?

To find the values that are causing issues (so you (or whoever designed this table) can fix them):

SELECT GRADUATION_DATE FROM mydb
  WHERE ISDATE(GRADUATION_DATE) = 0;

Bet you have at least one row. Fix those values, and then FIX THE TABLE. Or ask whoever designed the table to FIX THE TABLE. Really nicely.

ALTER TABLE mydb ALTER COLUMN GRADUATION_DATE DATE;

Now you don't have to worry about the formatting - you can always format as YYYYMMDD or YYYY-MM-DD on the client, or using CONVERT in SQL. When you have a valid date as a string literal, you can use:

SELECT CONVERT(CHAR(10), CONVERT(datetime, '20120101'), 120);

...but this is better done on the client (if at all).

There's a popular term - garbage in, garbage out. You're never going to be able to convert to a date (never mind convert to a string in a specific format) if your data type choice (or the data type choice of whoever designed the table) inherently allows garbage into your table. Please fix it. Or ask whoever designed the table (again, really nicely) to fix it.