DataTable dt = new DataTable();
            DataColumn dc1 = new DataColumn("Id", typeof(string));
            DataColumn dc2 = new DataColumn("Name", typeof(string));
            dt.Columns.Add(dc1);
            dt.Columns.Add(dc2);
            DataRow dr = dt.NewRow();
            dr["Id"] = "1004125120";
            dr["Name"] = "丁鹏";
            dt.Rows.Add(dr);
            DataRow dr2 = dt.NewRow();
            dr2["Id"] = "1004125121";
            dr2["Name"] = "张乐";
            dt.Rows.Add(dr2);

            // 1. 类似sql的Where后面跟的条件的查询语句 like、in 也可以
            DataRow[] drs = dt.Select("Name = ‘张乐‘ and Id in (‘1004125121‘,‘1004125120‘)");//返回DataRow[]

            // 2. 位DT设置主键，Find(主键值)查询
            //PrimaryKey是DT的一个属性 类型是DataColumn[]
            dt.PrimaryKey = new DataColumn[] { dt.Columns["Id"] };
            DataRow drSelect = dt.Rows.Find("1004125120");//返回DataRow