Question

is it possible to do dynamic declarations?
I will explain: I have a table COLUMNAMES:

ID|Name
 1|Country
 2|City
 3|District
 4|Neighbourhood

For each record in that table I would like to do something like:

declare @i int = 1
declare @number int
set @number = (SELECT count(*) FROM COLUMNNAMES)

While @i <= @number
BEGIN
Execute ('Declare column' + @i +'varchar(25)')
Execute ('set column' + @i +' = (Select NAME from COLUMNAMES where id = ' + @i)
set @i = @i + 1
END

The idea is that I get a list of variables (strings) that I can use to create SELECT statements with dynamic table-aliases:

 Execute ('Select SOMECOLUMN as ' + @columname +  @i +', ANOTHERCOLUMN as ' + @columname +  @i +', ATHIRDCOLUMN as ' + @columname +  @i + ' FROM SOMETABLE')

Can this be done? If so, how?

Answer 1

This is not complete solution but a direction . you need to get the value ‘SomeColumn’ dynamically someway ,likely the way you are getting the aliases in the below solution.

declare @i int = 1
declare @number INT
DECLARE @ColName VARCHAR(25)
DECLARE @SQL VARCHAR(4000)=''
DECLARE @ColumnsWithAlias VARCHAR(4000) = ''
set @number = (SELECT count(*) FROM COLUMNNAMES)

   While @i <= @number
  BEGIN

Select @ColName= NAME from COLUMNAMES where id =  @i)

SET @ColumnsWithAlias =@ColumnsWithAlias + 'SomeColumn'+ ' AS '+ @ColName + ' , '

   set @i = @i + 1
   END

   SET @SQL= 'SELECT '@ColumnsWithAlias+' FROM  TableName'

  EXECUTE(@SQL)