Duplicating rows based on a count column SQL Server
Below is an example using a join to a tally CTE. It would be better to create a materialized tally/numbers table to facilitate this sort of task going forward and improve performance too.

WITH
     t10 AS (SELECT n FROM (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) t(n))
    ,tally AS (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 0)) AS num FROM t10 AS a CROSS JOIN t10 AS b CROSS JOIN t10 AS c)
    ,codes AS (SELECT Code, SUM(CodeCount) AS CodeCount FROM dbo.MyTable WHERE Code = '1234A' AND PlaceID = 1 GROUP BY Code)
SELECT Code
FROM codes
JOIN tally ON tally.num &lt;= codes.CodeCount;