How to concatenate in SQL Server

Question

My database doesn\'t have a specific column so I created a column in my query by switch. What I need is to concatenate this column with another column in the database:

Answer 1

you must try this SQL query to contact the columns. Here I concat three columns of user table named (name_first, name_middle, name_last) and got the result into a single column named FULLNAME.

Here is the image of result