多表查询实例

public static DataTable GetAllFlow_Run_PrcsByPrcsFlagAndUserId(int prcsFlag, string userId)
 

       {

            string sqlAll = "select a.*,b.*,c.* from Flow_Run a,Flow_Type b,Flow_Run_Prcs c where a.RunId=c.RunId and a.FlowId=b.FlowId and c.PrcsFlag=" + prcsFlag + " and c.UserId='" + userId + "'";
              
            SqlCommand cmd = new SqlCommand(sqlAll, DBHelper.Connection);
                SqlDataReader dr = cmd.ExecuteReader();
                DataTable dt = new DataTable();
                dt.Columns.Add("RunId", typeof(System.Int32));
                dt.Columns.Add("RunName", typeof(System.String));
                dt.Columns.Add("FlowId", typeof(System.Int32));
                dt.Columns.Add("BeginUser", typeof(System.String));
                dt.Columns.Add("FlowName", typeof(System.String));
                dt.Columns.Add("FlowType", typeof(System.Int32));
                dt.Columns.Add("PrcsId", typeof(System.Int32));
                dt.Columns.Add("UserId", typeof(System.String));
                dt.Columns.Add("OpFlag", typeof(System.Int32));
                do
                {
                    while (dr.Read())
                    {
                        DataRow dtr = dt.NewRow();
                        dtr["RunId"] = dr["RunId"];
                        dtr["RunName"] = dr["RunName"];
                        dtr["FlowId"] = dr["FlowId"];
                        dtr["BeginUser"] = dr["BeginUser"];
                        dtr["FlowName"] = dr["FlowName"];
                        dtr["FlowType"] = dr["FlowType"];
                        dtr["PrcsId"] = dr["PrcsId"];
                        dtr["UserId"] = dr["UserId"];
                        dtr["OpFlag"] = dr["OpFlag"];
                        dt.Rows.Add(dtr);
                    }
                }
                while (dr.NextResult());
                return dt;
            }
    }