将一个表中的列值连接到另一个表的新列中的行

Question

I am trying to write a SQL query in SQL Server 2008 that will match the column values from a single query into a new column on a table where the column headers are stored as row values.

I have two queries:

KEY	VALUE
COL01	25
COL02	71
COL03	13

The same row values listed under the KEY column from table 1 are the column names for table 2.

COL01	COL02	COL03
XX	YY	ZZ

Desired result:

KEY	VALUE	NEW_COL
COL01	25	XX
COL02	71	YY
COL03	13	ZZ

Answer 1

Hmmm. . . I would suggest unpivoting and joining:

select t1.*, t2.val
from table2 t2 cross join
     (values (t2.col01, 'col01'), (t2.col02, 'col02'), (t2.col03, 'col03')
     ) v(val, which) join
     table1 t1
     on t2.which = t1.key;