Connecting two queries using UNION ALL - sql

Question

I want to connect the following two queries with union all.
First query is following:
WITH
week_source
AS
(SELECT week_desc,
TO_CHAR (day_date, 'IYYY') || 'W' || TO_CHAR (day_date, 'IW')
week,
(SELECT DISTINCT day_number
FROM period_day
WHERE day_key = d.day_key AND day_number NOT IN ('H', 'W') AND WEEK_NUM !=to_char(sysdate, 'WW')
)
workdays_count
FROM period_day d
WHERE TO_CHAR (day_date, 'IYYYIW') BETWEEN TO_CHAR (
(SYSDATE - 1) - 28,
'IYYYIW')
AND TO_CHAR (
(SYSDATE - 1),
'IYYYIW')
)
SELECT DISTINCT week_desc, week, workdays_count
FROM week_source
WHERE workdays_count IS NOT NULL
ORDER BY week;
It gives following table
The second query is:
SELECT 'W' || TO_CHAR (SYSDATE - 1, 'IW') WEEK_DESC,
TO_CHAR (SYSDATE - 1, 'IYYYIW') WEEK,
COUNT (day_date) WORKDAYS_COUNT
FROM period_day
WHERE day_number NOT IN ('H', 'W')
AND TO_CHAR (day_date, 'IYYYIW') =
TO_CHAR ((SYSDATE - 1), 'IYYYIW')
AND day_date <= (SYSDATE - 1)
which gives the following table
Any help?

Answer 1

You have to put order by clauseat the end.
If the first query returns 3 columns with data types varchar, int, varchar then the second query has to return columns of same data types.
WITH week_source AS
(SELECT week_desc,
TO_CHAR (day_date, 'IYYY') || 'W' || TO_CHAR (day_date, 'IW') week,
(SELECT DISTINCT day_number
FROM period_day
WHERE day_key = d.day_key
AND day_number NOT IN ('H', 'W')
AND WEEK_NUM !=to_char(sysdate, 'WW')) workdays_count
FROM period_day d
WHERE TO_CHAR (day_date, 'IYYYIW') BETWEEN
TO_CHAR ((SYSDATE - 1) - 28, 'IYYYIW')
AND
TO_CHAR ((SYSDATE - 1),'IYYYIW'))
SELECT DISTINCT week_desc, week, workdays_count
FROM week_source
WHERE workdays_count IS NOT NULL
union all
SELECT 'W' || TO_CHAR (SYSDATE - 1, 'IW') WEEK_DESC,
TO_CHAR (SYSDATE - 1, 'IYYYIW') WEEK,
to_char(COUNT(day_date)) WORKDAYS_COUNT
FROM period_day
WHERE day_number NOT IN ('H', 'W')
AND TO_CHAR (day_date, 'IYYYIW') = TO_CHAR ((SYSDATE - 1), 'IYYYIW')
AND day_date <= (SYSDATE - 1)
ORDER BY week
In this DEMO you can see the errors returning when the order by is located after the first query. Also you can see what error you get if I just remove the order by clause and this second error is because data types that first query is returning is different that the data types second row is returning. That is why I have added to_char to your count function in your second query. You could of also add to_number in your first query like this: SELECT DISTINCT to_number(day_number).