Pivot function and Missing expression error

Question

select * from (
select T.PAT_MRN_ID, T.ABBREVIATION,CONCEPT_VALUE from TBL_WORKLFOw T
pivot
max(concept_value)
for ABBREVIATION in (select ABBREVIATION from TBL_WORKLFOW )
this query is throwing "missing expression"..error.
Can some one help figuring out the problem.

Answer 1

Hi, Parth,
Parth Divekar wrote:
So your suggestion is to have it in a procedure ...form a dynamic sql using values from query and then execute the sql..That's one thing you can do.
You might also look into string aggregation, where you have one gargantuan column containing all the pivoted data from all the abbreviatons, no matter how many there are. That big column can be formatted so that it looks like several distinct columns.
Assuming dynamic SQL is the best answer, I find it easier to do in SQL*Plus, using files or substitution variables, as shown below. That's just my preference; you may like PL/SQL better.
How to Pivot a Table with a Dynamic Number of Columns
This works in any version of Oracle
The "SELECT ... PIVOT" feature introduced in Oracle 11
is much better for producing XML output.
Say you want to make a cross-tab output of
the scott.emp table.
Each row will represent a department.
There will be a separate column for each job.
Each cell will contain the number of employees in
     a specific department having a specific job.
The exact same solution must work with any number
of departments and columns.
(Within reason: there's no guarantee this will work if you
want 2000 columns.)
Case 0 "Basic Pivot" shows how you might hard-code three
job types, which is exactly what you DON'T want to do.
Case 1 "Dynamic Pivot" shows how get the right results
dynamically, using SQL*Plus. 
(This can be easily adapted to PL/SQL or other tools.)
PROMPT     ==========  0. Basic Pivot  ==========
SELECT     deptno
,     COUNT (CASE WHEN job = 'ANALYST'  THEN 1 END)     AS analyst_cnt
,     COUNT (CASE WHEN job = 'CLERK'    THEN 1 END)     AS clerk_cnt
,     COUNT (CASE WHEN job = 'SALESMAN' THEN 1 END)     AS salesman_cnt
FROM     scott.emp
WHERE     job     IN ('ANALYST', 'CLERK', 'SALESMAN')
GROUP BY     deptno
ORDER BY     deptno
PROMPT     ==========  1. Dynamic Pivot using Script  ==========
--     *****  Start of dynamic_pivot.sql  *****
-- Suppress SQL*Plus features that interfere with raw output
SET     FEEDBACK     OFF
SET     PAGESIZE     0
SPOOL     p:\sql\cookbook\dynamic_pivot_subscript.sql
SELECT     DISTINCT
     ',     COUNT (CASE WHEN job = '''
||     job
||     ''' '     AS txt1
,     'THEN 1 END)     AS '
||     job
||     '_CNT'     AS txt2
FROM     scott.emp
ORDER BY     txt1;
SPOOL     OFF
-- Restore SQL*Plus features suppressed earlier
SET     FEEDBACK     ON
SET     PAGESIZE     50
SPOOL     p:\sql\cookbook\dynamic_pivot.lst
SELECT     deptno
@@dynamic_pivot_subscript
FROM     scott.emp
GROUP BY     deptno
ORDER BY     deptno
SPOOL     OFF
--     *****  End of dynamic_pivot.sql  *****
EXPLANATION:
The basic pivot assumes you know the number of distinct jobs,
and the name of each one.  If you do, then writing a pivot query
is simply a matter of writing the correct number of ", COUNT ... AS ..."\
lines, with the name entered in two places on each one.  That is easily
done by a preliminary query, which uses SPOOL to write a sub-script
(called dynamic_pivot_subscript.sql in this example).
The main script invokes this sub-script at the proper point.
In practice, .SQL scripts usually contain one or more complete
statements, but there's nothing that says they have to.
This one contains just a fragment from the middle of a SELECT statement.
Before creating the sub-script, turn off SQL*Plus features that are
designed to help humans read the output (such as headings and
feedback messages like "7 rows selected.", since we do not want these
to appear in the sub-script.
Turn these features on again before running the main query.
PROMPT     ==========  2. Dynamic Pivot using Substitution Variable  ==========
--     *****  Preliminary Query:  *****
COLUMN     sql_txt_col     NEW_VALUE     sql_txt
WITH     all_jobs     AS
     SELECT DISTINCT
          job
     ,     DENSE_RANK () OVER (ORDER BY job)     AS r_num
     FROM     scott.emp
SELECT     SYS_CONNECT_BY_PATH ( job || '''     THEN 1 END) AS '
                      || job
                      || '_CNT'
                      || CHR (10)               -- Newline, for legibility only
                   , ', COUNT (CASE WHEN job = '''     -- Delimiter, goes before each entry
                   )                                       AS sql_txt_col
FROM     all_jobs
WHERE     CONNECT_BY_ISLEAF     = 1
START WITH     r_num = 1
CONNECT BY     r_num = PRIOR r_num + 1
--     *****  Main Query  *****
SELECT     deptno
&sql_txt     -- Ends with newline, so occupy that line
FROM     scott.emp
GROUP BY     deptno
ORDER BY     deptno
EXPLANATION:
Using a substitution variable is very similar to using a script.
The main difference is that the output of the preliminary query has to
go into one row.  This is done with SYS_CONNECT_BY_PATH, and getting
that requires that the jobs be numbered with consecutive integers, 1, 2, 3, ...
which we get from DENSE_RANK.
The NEWLINE character was added just to make the output line easier
to read during debugging.
*/