merge问题
定义ds用于存储最后结果
DataSet ds = new DataSet();
DataTable dt = new DataTable();
dt.Columns.Add(new DataColumn("油种", System.Type.GetType("System.String")));
dt.Columns.Add(new DataColumn("提单日", System.Type.GetType("System.DateTime")));
dt.Columns.Add(new DataColumn("入关日", System.Type.GetType("System.DateTime")));
dt.Columns.Add(new DataColumn("入关港口", System.Type.GetType("System.String")));
dt.Columns.Add(new DataColumn("提单分量(桶)", System.Type.GetType("System.Decimal")));
dt.Columns.Add(new DataColumn("提单分量(吨)", System.Type.GetType("System.Decimal")));
ds.Tables.Add(dt);
sql = "select YyJc as 油种,TdRq as 提单日,RgRq as 入关日期,RgGk as 入关港口,Tdflt as 提单分量(桶),Tdfld as 提单分量(吨) from ImportOil where ..."
importOilDS = importoil.GetInfo(sql);
ds.Merge(importOilDS); //此时异常“dataSet”参数不能为空
怎么解决?