column doesn't get calculated

this must be a problem with my sql, but this one has me stumped. the column:
Debit."cumm_dbt_blnce" - Credit."cumm_crd_blnce" in the long sql statement
below comes out as the literal: Debit."cumm_dbt_blnce" -
Credit."cumm_crd_blnce" rather than as the calculated value. WHY!?!?!

this works with simple sql:

select a."field1" - b."field2" from (select field1 as "field1" from
someTable) as a, (select field2 as "field2" from someOtherTable) as b;

but with my more complex sql, it doesn't. it comes out as a literal string.
it's almost like postgresql forgot to process this column.

select
cred_vend_acct_table.num as "num" ,
cred_vend_acct_table.name as "name" ,
abs_vend_acct_type_table.name as "name" ,
Debit."cumm_dbt_blnce" - Credit."cumm_crd_blnce" as "undefined" ,
Debit."cumm_dbt_blnce" as "cumm_dbt_blnce" ,
Credit."cumm_crd_blnce" as "cumm_crd_blnce" ,
cred_vend_acct_table.objid as "__OBJID__" ,
cred_vend_acct_table.clsref as "__CLSREF__"
from
only cred_vend_acct_table ,
abs_vend_acct_type_table ,
( select
daily_acct_blnce_table.cumm_dbt_blnce as "cumm_dbt_blnce"
from
only daily_acct_blnce_table
where
( ( ( daily_acct_blnce_table.company_objid *= 2147483647 ) ) and
( ( daily_acct_blnce_table.status = 'e' ) ) and
( daily_acct_blnce_table.abs_acct_objref[2] =
cred_vend_acct_table.objid ) and
( daily_acct_blnce_table.abs_acct_objref[1] =
cred_vend_acct_table.clsref ) and
daily_acct_blnce_table.dte =
( select
max(daily_acct_blnce_table.dte) as "dte"
from
only daily_acct_blnce_table
where
( ( ( daily_acct_blnce_table.company_objid *=
147483647 ) ) and
( ( daily_acct_blnce_table.status = 'e' ) ) and
( daily_acct_blnce_table.abs_acct_objref[2] =
cred_vend_acct_table.objid ) and
( daily_acct_blnce_table.abs_acct_objref[1] =
cred_vend_acct_table.clsref ) ) ) ) )
as Debit ,
( select
daily_acct_blnce_table.cumm_crd_blnce as "cumm_crd_blnce"
from
only daily_acct_blnce_table
where
( ( ( daily_acct_blnce_table.company_objid *= 2147483647 ) )
and
( ( daily_acct_blnce_table.status = 'e' ) ) and
( daily_acct_blnce_table.abs_acct_objref[2] =
cred_vend_acct_table.objid ) and
( daily_acct_blnce_table.abs_acct_objref[1] =
cred_vend_acct_table.clsref ) and
daily_acct_blnce_table.dte =
( select
max(daily_acct_blnce_table.dte) as "dte"
from
only daily_acct_blnce_table
where
( ( ( daily_acct_blnce_table.company_objid *=
2147483647 ) ) and
( ( daily_acct_blnce_table.status = 'e' ) ) and
( daily_acct_blnce_table.abs_acct_objref[2] =
cred_vend_acct_table.objid ) and
( daily_acct_blnce_table.abs_acct_objref[1] =
cred_vend_acct_table.clsref ) ) ) ) )
as Credit
where
( ( ( cred_vend_acct_table.company_objid *= 2147483647 ) and
( abs_vend_acct_type_table.company_objid *= 2147483647 ) ) and
( ( cred_vend_acct_table.status = 'e' ) and
( abs_vend_acct_type_table.status = 'e' ) ) and
cred_vend_acct_table.owner_objref[1] = 100110 and
cred_vend_acct_table.owner_objref[2] = 2147483647 and
( ( ( cred_vend_acct_table.abs_acct_type_objref[1] =
abs_vend_acct_type_table.clsref ) and
( cred_vend_acct_table.abs_acct_type_objref[2] =
abs_vend_acct_type_table.objid ) ) ) )
order by 2 asc
limit 100

Regards,

Floyd Shackelford
4 Peaks Technology Group, Inc.
VOICE: 334.735.9428
FAX: 702.995.6462
EMAIL: FloydS(at)4PeaksTech(dot)com
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PGP Fone at private.fwshackelford.com on request

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