How to SQL join tables, selecting the largest value in Access-VBA Function?

Question

I currently have the following Access VBA function, which operates as explained in a previous question (very useful for understanding this question):

Private Fun         


        

Answer 1

Encode value, decode max this way in SQL.

Currently you are building SQL command as (i replaced table name variables with arbitrary values, temp and tableName )

SELECT tbl_grp_by.*, [tableName].*  
INTO newTableName 
FROM (
    SELECT Max([temp].[Field1]) as [Field1], 
        Max([temp].[Field2]) as [Field2],  
        Max([temp].[Field3]) as [maxField3], 
        [temp].[Field4] as [Field4]  
    FROM [temp]
    INNER JOIN [tableName ]
       ON [temp].[commonField] = [tableName].[commonField] 
    GROUP BY [temp].[commonField]
 ) as tbl_grp_by  
INNER JOIN [tableName]
  ON [tableName].[commonField] = tbl_grp_by.[commonField]

Build it as

SELECT tbl_grp_by.[Field1],tbl_grp_by.[Field2],
    Switch( 
        tbl_grp_by.[maxfield3] = 0, '0',
        tbl_grp_by.[maxfield3] = 1, '>1 million',
        tbl_grp_by.[maxfield3] = 2 '0001-0010' 
    ) as [Field3],   
    tbl_grp_by.[Field4],
[tableName].*  
INTO newTableName 
FROM (
    SELECT Max([temp].[Field1]) as [Field1], 
        Max([temp].[Field2]) as [Field2],  
        Max(Switch(  
            [temp].[field3] = '0' , 0,
            [temp].[field3] = '>1 million' , 1,
            [temp].[field3] = '0001-0010', 2  
         ))as [maxField3], 
        [temp].[Field4] as [Field4]  
    FROM [temp]
    INNER JOIN [tableName ]
       ON [temp].[commonField] = [tableName].[commonField] 
    GROUP BY [temp].[commonField]
 ) as tbl_grp_by  
INNER JOIN [tableName]
  ON [tableName].[commonField] = tbl_grp_by.[commonField]   

So [field3] is encoded under max() in the inner query and that max is decoded in outer query.