Question : Conditional Concatenation in a Query

To simplify things, let's say I have a table containing 2 columns.  Column 1 contains a character prefix.  Column 2 contains numbers.  Here is an example of some values the table might contain:

Column 1               Column 2
     A                         100                          
     A                         200
     B                         300
     C                         700

Using a SELECT query, I want to concatenate the values in Column 1 and Column 2 except for when the value in Column 1 is 'B'.  If the value in Column 1 is 'B', then do not concatenate that row. Just show the Column 2 value in the query results for 'B' records.
 Here are the expected query results using the values I listed above:

A100
A200
   300
C700

Notice how with the 'B' record, it does not get concatenated. Only the Column 2 value is included in the query results for 'B' records.  In other words, if value in Column 1 equals 'B', do not concatenate. Only display the Column 2 value for 'B' records. All other records, concatenate.

Answer : Conditional Concatenation in a Query

select Column1, iif([Column1]="B", [Column2], [Column1]&[Column2]) AS YourColumnName
from yourtable


hth