Invalid Identifier -- SQL compilation error with multiple joins - snowflake-cloud-data-platform

Question

I am trying to run query with Multiple joins.
EX -
SELECT * FROM SC1.TABLE1 IHF
JOIN SC1.TABL2 IAF ON IHF.COL1 = IAF.COL1
AND IAF.COL2 = 'N'
AND IAF.COL2 = 2001
AND IHF.COL1 = 'N'
AND IAF.COL2 = 2001
LEFT OUTER JOIN SC1.TABL3 AID ON IAF.COL1 = AID.COL1
AND AID.COL2 = 2001
LEFT OUTER JOIN (
SELECT COL1 AS ID,UPPER(TRIM(COL2)) FROM SC1.TABLE4
WHERE COL3 = 'ADV' AND COL4 = 2001) AEM
ON COALESCE((UPPER(TRIM(AID.COL3))),'') = UPPER(TRIM(AEM.COL3));
But after running 2nd left join it gives SQL compilation error -invalid identifier c.col1
First left join works but 2nd gives error

Answer 1

so in Snowflake, using some made up data in the CTE it runs just for me.
with table1(col1) as (
select * from values
(1),(2),(3)
), table2(col2) as (
select * from values
(1),(2),(3)
), table3(col1, col2) as (
select * from values
(1,''),(2,'not empty'),(3,'')
)
Select
a.col1,
b.col2,
c.col1
from table1 a
join table2 b
ON a.col1 = b.col2
left outer join (
select col1 from table3 where col2=''
) c
on a.col1 = c.col1;
gives me the result:
COL1
COL2
COL1_2
1
1
1
2
2
null
3
3
3
can you provide better example data that triggers your problem, to scope your question better to which system (t-sql, snowflake) is giving you the problem, and again with what data.
Code update:
So two problems I can see inside AEM you output two columns, the second has no alias/label, And in the ON clause AEM.col3 correctly does not exist. Nether you need to select that also so it can be used OR the second select was meant to be aliased to that.
but if I rewrite your SQL:
SELECT
ihf.*,
iaf.*,
aid.*,
aem.id,
aem.clean_col2
FROM sc1.table1 AS ihf
JOIN sc1.tabl2 AS iaf
ON ihf.col1 = iaf.col1
AND iaf.col2 = 'N'
AND iaf.col2 = 2001
AND ihf.col1 = 'N'
AND iaf.col2 = 2001
LEFT OUTER JOIN SC1.TABL3 AID
ON IAF.COL1 = AID.COL1
AND AID.COL2 = 2001
LEFT OUTER JOIN (
SELECT
COL1 AS ID,
UPPER(TRIM(COL2)) as clean_col2,
col3
FROM SC1.TABLE4
WHERE COL3 = 'ADV' AND COL4 = 2001
) AEM
ON COALESCE((UPPER(TRIM(AID.COL3))),'') = UPPER(TRIM(AEM.COL3));
You can see I gave a name to the cleaned up col2 of AEM, but I would suggest you should move those "clean-ups" used in the ON into the related selects, so it can be a equi-join. But the join ON of IAF is broken as it stands:
JOIN sc1.tabl2 AS iaf
ON ihf.col1 = iaf.col1
AND iaf.col2 = 'N'
AND iaf.col2 = 2001
AND ihf.col1 = 'N'
AND iaf.col2 = 2001
how can iaf.col2 = 'N' AND iaf.col2 = 2001 at which point I would guess that was a typo, and it should read
JOIN sc1.tabl2 AS iaf
ON ihf.col1 = iaf.col1
AND iaf.col1= 'N'
AND iaf.col2 = 2001
AND ihf.col1 = 'N'
AND iaf.col2 = 2001
but that feels somewhat redundant, but at least Snowflake should push the filters to the correct spot.
but really I would tend to write the code as, for performance reasons:
SELECT
ihf.*,
iaf.*,
aid.*, -- mimus clean_col3
aem.id,
aem.clean_col2
FROM sc1.table1 AS ihf
JOIN sc1.tabl2 AS iaf
ON ihf.col1 = iaf.col1
AND iaf.col1 = 'N'
AND iaf.col2 = 2001
AND ihf.col1 = 'N'
AND iaf.col2 = 2001
LEFT OUTER JOIN (
SELECT *,
COALESCE((UPPER(TRIM(col3))),'') AS clean_col3
FROM sc1.tabl3
) AS aid
ON iaf.col1 = aid.col1
AND aid.col2 = 2001
LEFT OUTER JOIN (
SELECT
col1 AS id,
UPPER(TRIM(col2)) AS clean_col2,
UPPER(TRIM(aem.col3)) AS clean_col3
FROM sc1.table4
WHERE col3 = 'ADV' AND col4 = 2001
) AEM
ON AID.clean_col3 = AEM.clean_col3;