将xml文件上传到sql，关闭命令中的主键

我搜索了谷歌和youtube，当然在这里也找不到答案。我需要打开和关闭标识插入，但不知道如何在ADO.Net项目的sql命令中做到这一点。我相信这对你们这些经验丰富的人来说一定非常容易。

我正在使用c#、visual studio和sql server的其他信息，我不知道这是否有助于缩小问题范围？

这是我在ado.net项目中尝试的sql命令。

sql = "SET IDENTITY_INSERT HomeCareVisit ON insert into HomeCareVisit values(" 
       + VisitRefNo + ",'" + PatientNo + "','" + ScheduledDateTime + "','" 
       + TreatmentInstructions + "','" + MedicalStaffID + "','" + Priority + "','" 
       + ActualVisitDateTime + "','" + TreatmentProvided + "','" + Prescription 
       + "','" + AdvisoryNotes + "'," + (FurtherVisitRequired ? "1" : "0") + " );"; 

并给出错误

违反PRIMARY KEY约束"PK_VisitRefNo"。无法在对象"dbo.HomeCareVisit"中插入重复的密钥。语句已终止。

下面的代码显示了列的数据类型

VisitRefNo = ds.Tables[0].Rows[i].ItemArray[0].ToString();
PatientNo = Convert.ToInt32(ds.Tables[0].Rows[i].ItemArray[1]);
ScheduledDateTime = Convert.ToDateTime(ds.Tables[0].Rows[i].ItemArray[2]);
TreatmentInstructions = ds.Tables[0].Rows[i].ItemArray[3].ToString();
MedicalStaffID = Convert.ToInt32(ds.Tables[0].Rows[i].ItemArray[4]);
Priority = ds.Tables[0].Rows[i].ItemArray[5].ToString();
ActualVisitDateTime = Convert.ToDateTime(ds.Tables[0].Rows[i].ItemArray[6]);
TreatmentProvided = ds.Tables[0].Rows[i].ItemArray[7].ToString();
Prescription = ds.Tables[0].Rows[i].ItemArray[8].ToString();
AdvisoryNotes = ds.Tables[0].Rows[i].ItemArray[9].ToString();
FurtherVisitRequired = Convert.ToBoolean(ds.Tables[0].Rows[i].ItemArray[10]);

SET IDENTITY_INSERT YourTable ON

sql = "SET IDENTITY_INSERT HomeCareVisit ON insert into HomeCareVisit(column_names) values(" 
       + VisitRefNo + ",'" + PatientNo + "','" + ScheduledDateTime + "','" 
       + TreatmentInstructions + "','" + MedicalStaffID + "','" + Priority + "','" 
       + ActualVisitDateTime + "','" + TreatmentProvided + "','" + Prescription 
       + "','" + AdvisoryNotes + "'," + FurtherVisitRequired + " );";