PSQL query to comapre data from two instances of a database

Question

I have two instances of the same database from different days. All tables from one day are called tableA* and from the other tableB*. I would like to compare data to see what have changed. I would like to select all rows that don't match exactly. So for example if one value is different in tables tableA1 and tableB1 I would like to select a corresponding row from table A and mark it as 'new' and from table B and mark it as 'deleted'. I tried with a query like this:

SELECT 'new', ta1.name, ta2.name, ta3.name, ta4.name, ta5.name
FROM tableA1 ta1
LEFT JOIN tableA2 ta2 ON ta1.ta2_id = ta2.id
LEFT JOIN tableA3 ta3 ON ta1.ta3_id = ta3.id
LEFT JOIN tableA4 ta4 ON ta1.ta4_id = ta4.id
LEFT JOIN tableA5 ta5 ON ta5.ta1_id = ta1.id WHERE NOT EXISTS
(SELECT tb1.name, tb2.name, tb3.name, tb4.name, tb5.name
FROM tableB1 tb1
LEFT JOIN tableB2 tb2 ON tb1.tb2_id = tb2.id
LEFT JOIN tableB3 tb3 ON tb1.tb3_id = tb3.id
LEFT JOIN tableB4 tb4 ON tb1.tb4_id = tb4.id
LEFT JOIN tableB5 tb5 ON tb5.tb1_id = tb1.id WHERE 
tb1.name = ta1.name AND 
tb2.name = ta2.name AND 
tb3.name = ta3.name AND 
tb4.name = ta4.name AND 
tb5.name = ta5.name)
UNION
SELECT 'deleted', tb1.name, tb2.name, tb3.name, tb4.name, tb5.name
FROM tableB1 tb1
LEFT JOIN tableB2 tb2 ON tb1.tb2_id = tb2.id
LEFT JOIN tableB3 tb3 ON tb1.tb3_id = tb3.id
LEFT JOIN tableB4 tb4 ON tb1.tb4_id = tb4.id
LEFT JOIN tableB5 tb5 ON tb5.tb1_id = tb1.id WHERE NOT EXISTS
(SELECT ta1.name, ta2.name, ta3.name, ta4.name, ta5.name
FROM tableA1 ta1
LEFT JOIN tableA2 ta2 ON ta1.ta2_id = ta2.id
LEFT JOIN tableA3 ta3 ON ta1.ta3_id = ta3.id
LEFT JOIN tableA4 ta4 ON ta1.ta4_id = ta4.id
LEFT JOIN tableA5 ta5 ON ta5.ta1_id = ta1.id WHERE 
tb1.name = ta1.name AND 
tb2.name = ta2.name AND 
tb3.name = ta3.name AND 
tb4.name = ta4.name AND 
tb5.name = ta5.name)

Hoping that if I created the same stuructre and compare all the values I would get the anticipated result. Even if databases are the same I get a lot row selected.

Answer 1

Found the problem. When comparing two NULL values the result is FALSE, the query itself should be fine. So I should have added conditions to check whether values are NULL.