What is max doing across fields in a de-duplication ?

[Jack]

Greetings folks,

Just curious if anyone knows what the following would produce:
SELECT
MAX( ECP_SUPPORT_DED _EMAIL.CD_TYP_C MPGN) CD_TYP_CMPGN,
MAX(ECP_SUPPORT _DED_EMAIL.CELL _ID) CELL_ID,
ECP_SUPPORT_DED _EMAIL.CLIC_CUS T_ID CUSTID,
MAX( ECP_SUPPORT_DED _EMAIL.ADDRESS) CONTACTED_PARTY ID,
MAX( ECP_SUPPORT_DED _EMAIL.CONTACTE D_PARTY_ID_TYPE )
FROM
ECP_SUPPORT_DED _EMAIL
group by CUSTID

For a given CUSTID, and assuming all fields are character and there
are duplicates, will it randomly select the MAX value of any of these
fields across duplicates, or will it randomly select a custID and
retain that row's attributes with integrity?

thanks!
Jack

[Jan]

I have no idea, but let`s guess - it will return the max values of the
rows for each custid?

ja***********@y ahoo.com (Jack) wrote in message news:<20******* *************** ****@posting.go ogle.com>...

Greetings folks,

Just curious if anyone knows what the following would produce:
SELECT
MAX( ECP_SUPPORT_DED _EMAIL.CD_TYP_C MPGN) CD_TYP_CMPGN,
MAX(ECP_SUPPORT _DED_EMAIL.CELL _ID) CELL_ID,
ECP_SUPPORT_DED _EMAIL.CLIC_CUS T_ID CUSTID,
MAX( ECP_SUPPORT_DED _EMAIL.ADDRESS) CONTACTED_PARTY ID,
MAX( ECP_SUPPORT_DED _EMAIL.CONTACTE D_PARTY_ID_TYPE )
FROM
ECP_SUPPORT_DED _EMAIL
group by CUSTID

For a given CUSTID, and assuming all fields are character and there
are duplicates, will it randomly select the MAX value of any of these
fields across duplicates, or will it randomly select a custID and
retain that row's attributes with integrity?

thanks!
Jack

[Ed prochak]

ja***@pobox.sk (Jan) wrote in message news:<81******* *************** ****@posting.go ogle.com>...

I have no idea, but let`s guess - it will return the max values of the
rows for each custid?

ja***********@y ahoo.com (Jack) wrote in message news:<20******* *************** ****@posting.go ogle.com>...

Greetings folks,

Just curious if anyone knows what the following would produce:
SELECT
MAX( ECP_SUPPORT_DED _EMAIL.CD_TYP_C MPGN) CD_TYP_CMPGN,
MAX(ECP_SUPPORT _DED_EMAIL.CELL _ID) CELL_ID,
ECP_SUPPORT_DED _EMAIL.CLIC_CUS T_ID CUSTID,
MAX( ECP_SUPPORT_DED _EMAIL.ADDRESS) CONTACTED_PARTY ID,
MAX( ECP_SUPPORT_DED _EMAIL.CONTACTE D_PARTY_ID_TYPE )
FROM
ECP_SUPPORT_DED _EMAIL
group by CUSTID

For a given CUSTID, and assuming all fields are character and there
are duplicates, will it randomly select the MAX value of any of these
fields across duplicates, or will it randomly select a custID and
retain that row's attributes with integrity?

thanks!
Jack

First there is nothing RANDOM about it.

MAX() returns the largest value of the COLUMN.

so for mytable:
cmpgn cell custid
xxxx abc 234
aaaa xyz 234

select max(cmpgn), max(cell), custid
from mytable group by custid ;

returns
max(cmpgn) max(cell) custid
xxxx xyz 234

hth,
ed