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Question

public DataTable SearchProduct(string Region,string ProductName, string Manufacturer)
        {
            string strSql = string.Empty;
            strSql = "SELECT " +
                        "Guid ," +
                        "ProductNumber ," +
                        "ProductName ," +
                        "ProductStyle ," +
                        "ProductOrigin ," +
                        "PackUnit ," +
                        "ReferencePrice ," +
当Region = NUll时候要求ReferencePrice 列的值都为*   该怎么修改？

Answer 1

 "ReferencePrice ," +
------> "ReferencePrice = case when Region is null then '*' else ReferencePrice end ," +

Answer 2

 SearchProduct(string Region,string ProductName, string Manufacturer)
是Region参数

Answer 3

...string strSql = string.Empty;
  strSql = "SELECT " +
  "Guid ," +
  "ProductNumber ," +
  "ProductName ," +
  "ProductStyle ," +
  "ProductOrigin ," +
  "PackUnit ," 
  if Region = string.Empty
     strSql =  strSql +
  "ReferencePrice ='*'," 
  else
     strSql =  strSql +
  "ReferencePrice ,"   strSql =  strSql + ...