Converting Varchar to Int error I came across an issue today, and while I was able to fix it, I am unsure what caused the issue to happen.

I have a column that is Varchar(20).  It is used to store just year data (2010, 2011, etc.)  it is being converted to an Int data type, but when the command below is ran, an error code happens.

ALTER TABLE mytable ALTER COLUMN1 int NULL


The error displayed is: Conversion failed when converting the varchar value '2010.          ' to data type int.

There are 3 rows in the table with the value of 2010 in Column1, but NO rows with '2010.          ' (period and 10 spaces) as a value.  I ran 

select len(Column1) from MyTable where Column1 like '%2010%'


I got 2 rows with a length of 4, and 1 with a length of 5.  After updating the row with 5 length to have 2010 as the value, the table could be altered.  

I am curious where the period and spaces came from here.  Also curious how 1 character length increase results in a period and 10 spaces.  I am thinking something along the lines of a carriage return or line feed, but I can't find any data to back that up, its just a hunch.
LEN() in most SQL distributions do not include spaces.  You would want to use something like DATALENGTH() for that. 
https://stackoverflow.com/questions/1151693/len-vs-datalength-in-sql-server-2005
As for where the '.' and spaces came from, we would need more information like how is that field being populated?  What app, directly via SQL, etc.
Also, it would be helpful to know what distribution you are using.  I assumed SQL Server.