ADO复习4(3)

//定义数据集ds

DataSet ds=new DataSet();

//定义数据适配器和连接对象

SqlConnection cn = new SqlConnection(connstr);

SqlDataAdapter da = new SqlDataAdapter(\From subject\

da.Fill(ds, \

cbSubject.DataSource=ds.Tables[\ cbSubject.DisplayMember=\ cbSubject.ValueMember=\ } } }

63.select classID,COUNT(*) FROM student GROUP BY classID

64.DataSet ds = new DataSet();

DataTable dt = new DataTable(\ds.Tables.Add(dt);

DataColumn dc1 = new DataColumn(\dt.Columns.Add(dc1);

DataColumn dc2 = new DataColumn(\dt.Columns.Add(dc2);

DataColumn dc3 = new DataColumn(\dt.Columns.Add(dc3);

DataRow newrow1 = dt.NewRow(); newrow1[\newrow1[\newrow1[\

dt.Rows.Add(newrow1);

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