How to concatenate in SQL Server

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庸人自扰
庸人自扰 2021-01-28 01:34

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:



        
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  • 2021-01-28 01:41

    To concatenate strings in SQL Server you can simply use the + operator.
    Note that if one of the substrings is null then the entire concatenated string will become null as well. therefor, use COALESCE if you need a result even if one substring is null.

    select certificateDuration,
           ' DurationType = '+ 
           COALESCE(case
                         when certificateDurationType = 0 then 'Day' 
                         when certificateDurationType = 1 then 'Month'
                         when certificateDurationType = 2 then 'Year'
                         end, '') As DurationType 
    from Scientific_Certification
    

    Note: I've used coalesce on your case clause since you have no default behavior (specified by else). this means that if certificateDurationType is not 0, 1 or 2 the case statement will return null.

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  • 2021-01-28 01:44

    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

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  • 2021-01-28 01:48

    You just need to try + operator or CONCAT function

    1. + for all SQL Server versions

      DurationType = ' + 'some text'
      
    2. CONCAT for SQL Server 2012 +

      CONCAT('DurationType = ', 'some text')
      

    Your query should be something like this

    SELECT certificateDuration
           ,'DurationType = ' + 
           CASE certificateDurationType
               WHEN 0 THEN 'Day'
               WHEN 1 THEN 'Month'
               WHEN 2 THEN 'Year'
           END
    FROM Scientific_Certification
    
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