SELECT

"Union"."Date" AS "Date",

"Union"."GL Number" AS "GL Number",

"Union"."Value" AS "Value",  

SUM("Union"."Value") OVER(PARTITION BY "Union"."GL Number"  ORDER BY "Union"."Date" ASC  ROWS  BETWEEN  UNBOUNDED  PRECEDING  AND  CURRENT  ROW ) AS "Balance"

FROM(

SELECT

"tblJournal"."dteJournalDate" AS "Date",

"tblJournalEnt"."intGLNumber" AS "GL Number",

"tblJournalEnt"."decDebits"-"tblJournalEnt"."decCredits" AS "Value"

FROM "tblJournal"

LEFT JOIN "tblJournalEnt" ON "tblJournal"."lngJourID" = "tblJournal"."lngJourID"

UNION ALL SELECT

"tblJournalLY"."dteJournalDate" AS "Date",

"tblJournalEntLY"."intGLNumber" AS "GL Number",

"tblJournalEntLY"."decDebits"-"tblJournalEntLY"."decCredits" AS "Value"

FROM "tblJournalLY"

LEFT JOIN "tblJournalEntLY" ON "tblJournalLY"."lngJourID" = "tblJournalLY"."lngJourID"

UNION ALL SELECT

"tblJournalHist"."dteJournalDate" AS "Date",

"tblJournalEntHist"."intGLNumber" AS "GL Number",

"tblJournalEntHist"."decDebits"-"tblJournalEntHist"."decCredits" AS "Value"

FROM "tblJournalHist"

LEFT JOIN "tblJournalEntHist" ON "tblJournalHist"."lngJourID" = "tblJournalHist"."lngJourID")

AS "Union"