Question : Find all records that don't exist n a table

I have a 2 tables; one is a lookup table that holds just an ID and a description. The other holds community data and dates and links to the lookup table by the budgetdefinitionidy. I want to find any communities that are missing one of the 11 budget description. Here is the query I started:

SELECT DISTINCT
      Bl.CommunityName,
      Bl.Datebegin,
      Bld.BudgetDescription
FROM LCSInsight_ExtractBudgetLeads Bl CROSS JOIN LCSInsight_ExtractBudgetLeadsDim Bld
ON Bl.BudgetDefinitionIDY = Bld.BudgetDefinitionIDY
WHERE
      BL.CommunityID = 10
AND Bld.BudgetDefinitionDescription NOT IN (SELECT
       BudgetDescription
FROM LCSInsight_ExtractBudgetLeadsDIM

Answer : Find all records that don't exist n a table

> I want to find any communities
that is defined by the field BL.CommunityID, which is the same for up to 11 rows?

if that is the design (not really good, but anyhow), what about this start:

                       
               SELECT B.CommunityID, Bld.BudgetDefinitionIDY 
    FROM (SELECT CommunityID FROM LCSInsight_ExtractBudgetLeads GROUP BY CommunityID ) B
    CROSS JOIN LCSInsight_ExtractBudgetLeadsDim Bld
    WHERE NOT EXISTS ( SELECT NULL FROM LCSInsight_ExtractBudgetLeads Bl
                       WHERE Bl.CommunityID = B.CommunityID
                         AND B1.BudgetDefinitionIDY = Bld.BudgetDefinitionIDY 
                     )