数据多表连接问题,请指教
我先建两个表人员表和部门表,它们通过iDrpDepID进行连接
CREATE TABLE TDrpPerson( iDrpPersonID INT NOT NULL IDENTITY,
cName VARCHAR(20) NOT NULL, --姓名
iDrpDepID INT NOT NULL) --所属部门
CREATE TABLE TDrpDep (iDrpDepID INT NOT NULL IDENTITY,
cName VARCHAR(60) NOT NULL) --部门名称
接下去是C#代码,建立这两个表的连接,它提示这些列当前不具有唯一值,代码如下
string myConnectionString="";
if(myConnectionString == "")
{
myConnectionString = "Initial Catalog=drpkt;Data Source=localhost;Integrated Security=SSPI;";
}
SqlConnection myConnection = new SqlConnection(myConnectionString);
myConnection.Open();
string SQL="select * from tdrpperson;select * from tdrpdep";
string SQL1="select * from tdrpdep;";
SqlDataAdapter da=new SqlDataAdapter(SQL,myConnection);
SqlDataAdapter da1=new SqlDataAdapter(SQL1,myConnection);
dataSet1=new DataSet ();
da.Fill(dataSet1,"tdrpperson");
da1.Fill(dataSet1,"tdrpdep");
System.Data.DataRelation dr;
System.Data.DataColumn dc1;
System.Data.DataColumn dc2;
dc1 = dataSet1.Tables["tdrpperson"].Columns["iDrpDepID"];
dc2 = dataSet1.Tables["tdrpdep"].Columns["iDrpDepID"];
//问题处
dataSet1.Relations.Add("persondep", dc1, dc2);
myConnection.Close();