You may need to change the SQL
"SELECT VALUE FROM dbo.COMMON_CONFIG WHERE VALUE = '" + src + "'";
you send the value and again select the value!!!
I think you may need get the value by Name
, something like below
"SELECT VALUE FROM dbo.COMMON_CONFIG WHERE Name= '" + src + "'";
change it accordingly, as your database column names, and this is apply to all your SQL strings
Note: Use SQL Parameters and using statements