问题
I want to fetch records from oracle DB where column value is NULL
. Also i am using unpivot
in my query. Somehow NULL
values are not getting selected because of unpivot
keyword. Can you please help me about how to get rows for the same when using unpivot
.
EDIT:
SELECT a.emp_id, a.emp_dept, b.emp_location
FROM employee a,
location b UNPIVOT (emp_id
FOR dummy_id
IN (emp_id AS 'EMP_ID', last_date AS 'LAST_DATE'))
WHERE emp_id = 123 AND b.emp_loc_id = 'india' AND b.location IS NULL;
回答1:
Use UNPIVOT INCLUDE NULLS:
SQL Fiddle
Oracle 11g R2 Schema Setup:
CREATE TABLE test ( id, a, b, c, d ) AS
SELECT 1, 1, 2, 3, 4 FROM DUAL UNION ALL
SELECT 2, 1, NULL, 3, NULL FROM DUAL;
Query 1:
SELECT *
FROM test
UNPIVOT INCLUDE NULLS ( value FOR name IN ( a, b, c, d ) )
Results:
| ID | NAME | VALUE |
|----|------|--------|
| 1 | A | 1 |
| 1 | B | 2 |
| 1 | C | 3 |
| 1 | D | 4 |
| 2 | A | 1 |
| 2 | B | (null) |
| 2 | C | 3 |
| 2 | D | (null) |
来源:https://stackoverflow.com/questions/46763223/oracle-querying-null-values-in-unpivot-query