How to add dynamic column to an existing table

Question

I have 2 tables 1st table contains following columns,

 id code    Name
 1  c1  chk1
 2  c2  chk2
 3  c3  chk3

2nd table contains following columns,

id,Name,Chk1,chk2,Chk3

i have to add the column 'Chk4' into table2 if table1 is updated with value '4,'c4','ch4' dynamically.How to write procedure to perform this?

i've tried the following procedure but its not working fine.

         create proc Add_Check
          as 
          begin
          declare @Column varchar(50)
          declare @query varchar(255)
          declare @query1 varchar(255)
          set @Column= (select top 1 QUOTENAME(Name)
            from table1 where id=(Select MAX id) from table1))
          if exists(select 1 from table1
         where Name=@Column) 
         begin
         set @query = 'alter table table2 add ' + @Column + ' Varchar (50)'
         set @query1 = 'alter table table2 add ' + @Column + '_CompletedDate Varchar (50)'
         exec(@query)
         end
         end

Solution

use this query as procedure.

CREATE PROC ADD_CHECK
AS 
BEGIN
    DECLARE @COLUMN VARCHAR(50)
    DECLARE @QUERY VARCHAR(255)
    DECLARE @QUERY1 VARCHAR(255)

    SET @COLUMN= (SELECT TOP 1 NAME FROM TABLE1 WHERE ID=(SELECT MAX (ID)     FROM TABLE1))

    IF EXISTS(SELECT 1 FROM TABLE1 WHERE NAME=@COLUMN) 
    BEGIN
        SET @QUERY = 'ALTER TABLE TABLE2 ADD ' + @COLUMN + ' VARCHAR (50)'
        SET @QUERY1 = 'ALTER TABLE TABLE2 ADD ' + @COLUMN + '_COMPLETEDDATE VARCHAR     (50)'
        EXEC(@QUERY)
    END
END

Comments

[Ritesh Khatri]

like my answer if you satisfied withmy answer

[Ritesh Khatri]

it's about create procedure than why use to trigger.

[user2514925]

Its getting execute but the new column not getting added

[Ritesh Khatri]

you use QUOTENAME() function that why it's create problm. remove QUOTENAME() than you get successfully result

[user2514925]

i have declared another variable and added '_COMPLETEDDATE' string in it.its working fine now.Thank you..