Fill data gaps - UNION, PARTITION BY, or JOIN?

Problem

There are data gaps that n开发者_Go百科eed to be filled. Would like to avoid UNION or PARTITION BY if possible.

Query Statement

The select statement reads as follows:

SELECT
  count( r.incident_id ) AS incident_tally,
  r.severity_cd,
  r.incident_typ_cd
FROM
  report_vw r
GROUP BY
  r.severity_cd, r.incident_typ_cd
ORDER BY
  r.severity_cd,
  r.incident_typ_cd

Data Sources

The severity codes and incident type codes are from:

• severity_vw
• incident_type_vw

The columns are:

• incident_tally
• severity_cd
• incident_typ_cd

Actual Result Data

36  0   ENVIRONMENT
1   1   DISASTER
27  1   ENVIRONMENT
4   2   SAFETY
1   3   SAFETY

Required Result Data

36  0   ENVIRONMENT
0   0   DISASTER
0   0   SAFETY
27  1   ENVIRONMENT
0   1   DISASTER
0   1   SAFETY
0   2   ENVIRONMENT
0   2   DISASTER
4   2   SAFETY
0   3   ENVIRONMENT
0   3   DISASTER
1   3   SAFETY

Question

How would you use UNION, PARTITION BY, or LEFT JOIN to fill in the zero counts?

How about something like

SELECT  COUNT(r.incident_id),
        crsjn.severity_cd,
        crsjn.incident_typ_cd
FROM    (
            SELECT  severity_cd,
                    incident_typ_cd
            FROM    severity_vw,
                    incident_type_vw
        ) crsjn LEFT JOIN
        report_vw r     ON  crsjn.severity_cd = r.severity_cd 
                        AND crsjn.incident_typ_cd = r.incident_typ_cd
GROUP BY crsjn.severity_cd,
        crsjn.incident_typ_cd
ORDER BY crsjn.severity_cd,
        crsjn.incident_typ_cd

The easiest would be if you had incident type and incident severity in another table.

SELECT COALESCE(sub.incident_tally), s.severity_cd, i.incident_type_cd
FROM incident_type i
CROSS JOIN incident_severity s
LEFT JOIN (
   ... your original sql statement...
) sub ON i.incident_typ_cd = sub.incident_type_cd
  AND s.severity_cd = sub.severity_cd

And if you didn't have those tables, you could do something like this. I don't understand why the no UNION restriction. But this works.

CREATE TYPE VARCHAR_TABLE AS TABLE OF VARCHAR2(60);
CREATE TYPE NUMBER_TABLE AS TABLE OF NUMBER;

WITH inc AS (
  SELECT /*+ CARDINALITY(nt1 3) */ column_value AS incident_type_cd
  FROM TABLE(varchar_table('ENVIRONMENT', 'DISASTER', 'SAFETY')) nt1
),
sev AS (
  SELECT /*+ CARDINALITY(nt2 4) */ column_value AS severity_cd
  FROM TABLE(number_table(0,1,2,3)) nt2
) 
SELECT *
FROM inc
CROSS JOIN sev
LEFT JOIN (
   ... your original sql statement...
) sub ON i.incident_typ_cd = sub.incident_type_cd
  AND s.severity_cd = sub.severity_cd

4

The only way i can think of is to further normalise that table and use a left join.