If you have a situation where you want to add a column into a table in SQL Server, it would be a good idea to perform a check first if a column has already existed in a table. Otherwise, if you try to add a duplicate column, you may get an error message when you try to add a column via SQL query.
To replace a break line is pretty simple, The Carriage return is represented by CHAR(13), while the Line Feed is represented by CHAR(10). You can use the following example replace method to do it.
REPLACE(REPLACE(REPLACE(FIELD_VALUE, CHAR(13) + CHAR(10), 'something else'), CHAR(13), 'REPLACE_VALUE'), CHAR(10), 'REPLACE_VALUE')