如何在SQL中为标识符设置别名

Question

Concept example:

declare @x varchar(max)

set @x = 'top 1 *'

select @x from table

---

Result wanted:

For the script to function as:

select top 1 * from table

To return the first row in table.

---

Actual result:

The script functions as:

select 'top 1 *' from table

Many rows return with values 'top 1 *'

---

Use case:

In a more complex scenario, the x variable would be a much longer string that would need to be called upon several times later in the script. Instead of pasting that long variable over and over, I want to set an alias for it. Is this possible?

Answer 1

I think you want this:

declare @x varchar(max), @sql varchar(max)

set @x = 'top 1 *'

set @sql = 'select '+ @x +' from table'

PRINT @sql;

--EXECUTE (@sql) -- Uncomment this when you are sure of your query