Oracle compare tables to the previous day - sql

Question

I have been tasked with comparing some tables in my DB with how they were the previous day, in terms of number of rows mainly.
I guess I could write manually a procedure storing the number of rows in the tables and then going the day after and comparing against the stored numbers looking for unexpected variations, but.
Is there any standard way in Oracle that would do this in a cleaner way?

Answer 1

If it is about some dayly table statistics and if you have a date column in your table that you can use (date of document or update or insert or....) you could try something like here:
Select DISTINCT
d.TABLE_DATE,
Sum(CASE WHEN t.DELIVERY_DATE < d.TABLE_DATE THEN 1 ELSE 0 END) OVER(Partition By d.TABLE_DATE Order By d.TABLE_DATE DESC) "ROWS_BEFORE",
Sum(CASE WHEN t.DELIVERY_DATE = d.TABLE_DATE - 1 THEN 1 ELSE 0 END) OVER(Partition By d.TABLE_DATE Order By d.TABLE_DATE DESC) "ROWS_YESTERDAY",
Sum(CASE WHEN t.DELIVERY_DATE = d.TABLE_DATE THEN 1 ELSE 0 END) OVER(Partition By d.TABLE_DATE Order By d.TABLE_DATE DESC) "ROWS_TODAY",
Sum(CASE WHEN t.DELIVERY_DATE <= d.TABLE_DATE THEN 1 ELSE 0 END) OVER(Partition By d.TABLE_DATE Order By d.TABLE_DATE DESC) "TOTAL_ROWS",
TRUNC(SYSDATE) "REPORTING_DATE"
From dates d
Left Join tbl t ON(1 = 1)
Order By d.TABLE_DATE DESC
If we try it with data like below:
WITH
tbl(ID, ITEM_ID, ITEM_NAME, DELIVERY_DATE ) AS
(
Select 1 "ID", 1 "ITEM_ID", 'Item 1' "ITEM_NAME", To_Date('24.01.2023', 'dd.mm.yyyy') "DELIVERY_DATE" From Dual Union All
Select 2, 1, 'Item 1', To_Date('21.01.2023', 'dd.mm.yyyy') From Dual Union All
Select 3, 1, 'Item 1', To_Date('20.01.2023', 'dd.mm.yyyy') From Dual Union All
Select 4, 1, 'Item 1', To_Date('20.01.2023', 'dd.mm.yyyy') From Dual Union All
Select 5, 1, 'Item 1', To_Date('19.01.2023', 'dd.mm.yyyy') From Dual Union All
Select 3, 2, 'Item 2', To_Date('19.01.2023', 'dd.mm.yyyy') From Dual Union All
Select 4, 3, 'Item 3', To_Date('18.01.2023', 'dd.mm.yyyy') From Dual Union All
Select 5, 3, 'Item 3', To_Date('23.01.2023', 'dd.mm.yyyy') From Dual Union All
Select 6, 3, 'Item 3', To_Date('22.01.2023', 'dd.mm.yyyy') From Dual
),
dates AS
( Select TRUNC(SYSDATE) - (LEVEL - 1) "TABLE_DATE" From DUAL CONNECT BY LEVEL <= 7 )
ID
ITEM_ID
ITEM_NAME
DELIVERY_DATE
1
1
Item 1
24-JAN-23
5
3
Item 3
23-JAN-23
6
3
Item 3
22-JAN-23
2
1
Item 1
21-JAN-23
3
1
Item 1
20-JAN-23
4
1
Item 1
20-JAN-23
3
2
Item 2
19-JAN-23
5
1
Item 1
19-JAN-23
4
3
Item 3
18-JAN-23
... dates is a CTE defining how many days before sysdate you want to get.
R e s u l t :
TABLE_DATE
ROWS_BEFORE
ROWS_YESTERDAY
ROWS_TODAY
TOTAL_ROWS
REPORTING_DATE
26-JAN-23
9
0
0
9
26-JAN-23
25-JAN-23
9
1
0
9
26-JAN-23
24-JAN-23
8
1
1
9
26-JAN-23
23-JAN-23
7
1
1
8
26-JAN-23
22-JAN-23
6
1
1
7
26-JAN-23
21-JAN-23
5
2
1
6
26-JAN-23
20-JAN-23
3
2
2
5
26-JAN-23