Question

When we do SELECT * FROM table we get all records in a table, If I want to get only a row but do not know the number of columns

like

id   att1  att2  att3.... attx
-------------------------------
1     45     5      3        7

How do I do a select statement that returns all columns?
I know I must use

from INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'myTable'

and a Where clause: WHERE id = 1

but again I do not know the number of columns…

Answer 1

Just add a where clause to the end of the @sql statement to limit your selection to the rows you want:

declare @cols nvarchar(max)

select @cols = coalesce(@cols + ', ' + column_name, column_name)
from information_schema.COLUMNS
where TABLE_NAME = 'mytable'

declare @sql nvarchar(max)
select @sql = 'select ' + @cols + ' from myTable where Id = 1'

exec sp_executesql @sql