迁移后用于分析数据的SQL

Question

I have a lot of data migrated and now wants to check them for correctness.

Below is a simple example: I have migrated a table which was already filled in another. Now I want to check the number of both tables and compare. In addition I have created the following query:

SELECT 'Prüfung1' AS "Prüfung", (CASE 
    WHEN (SELECT count(*) FROM TableA) = (SELECT count(*) FROM TableB)
    THEN 'OK!' 
    ELSE '!!! Anzahl stimmt nicht überein !!!' END) "Ergebnis" FROM dual

However, I would carry out several such tests, and show as one result. If I will be replacements in a second test this appears as a column rather than a row.

SELECT * FROM (
    SELECT 'Prüfung1' AS "Prüfung", (CASE 
    WHEN (SELECT count(*) FROM TableA) = (SELECT count(*) FROM TableB)
    THEN 'OK!' 
    ELSE '!!! Anzahl stimmt nicht überein !!!' END) "Ergebnis" FROM dual) check1,
    (
    SELECT 'Prüfung2' AS "Prüfung", (CASE 
    WHEN (SELECT count(*) FROM TableC) = (SELECT count(*) FROM TableD)
    THEN 'OK!' 
    ELSE '!!! Anzahl stimmt nicht überein !!!' END) "Ergebnis" FROM dual) check2;

My Result should be:

|Tests|Result|
|Check1|Result1|
|Check2|Result2|
|Check3|Result3|
...

How can I do that best?

Sorry for my englsih! ;-)

Update for @vercelli

Here the query with the ORA-00904 Error:

with myTables as (select 'tableA' as tableName, count(*) as howMany from MIGRATION_OLDTABLE1 union all
              select 'tableB' as tableName, count(*) as howMany from OLDTABLE1 union all
              select 'tableC' as tableName, count(*) as howMany from MIGRATION_OLDTABLE2 union all
              select 'tableD' as tableName, count(*) as howMany from OLDTABLE2
              --....
              --select 'tableN' as tableName, count(*) from TableC
              ),
myRelations (select 'tableA' as newTable, 'tableB' as oldtable from dual union all
             select 'tableC' as newTable, 'tableD' as oldtable from dual )
select DECODE(a1.howMany, a2.howMany, 'OK', 'KO') as results , r.newTable ||' : ' || to_char(a1.howMany) ||' vs. '|| r.oldTable || ' : ' || to_char(a2.howMany) diff
from myTables a1 join myRelations r on a1.tableName = r.newTable
               join myTables a2 on a2.tableName = r.oldTable;

Answer 1

I'd create a subquery with the count(*) of all the tables with their tableName . Another subquery with all the relations ( newTable vs. oldTable ) Then join them and compare the count(*) .

with myTables as (select 'tableA' as tableName, count(*) as howMany from tableA union all
                  select 'tableB' as tableName, count(*) as howMany from tableB union all
                  ....
                  select 'tableN' as tableName, count(*) from tableN),
    myRelations as (select 'tableA' as newTable, 'tableB' as oldtable from dual union all
                 select 'tableC' as newTable, 'tableD' as oldtable from dual )
select DECODE(a1.howMany, a2.howMany, 'OK', 'KO') as results , r.newTable ||' : ' || to_char(a1.howMany) ||' vs. '|| r.oldTable || ' : ' || to_char(a2.howMany) diff
  from myTables a1 join myRelations r on a1.tableName = r.newTable
                   join myTables a2 on a2.tableName = r.oldTable
  ;

SAMPLE OUTPUT

results diff
  KO    tableA : 5624 vs. tableB: 5476
  OK    tableC : 1576 vs. tableD: 1576