C#—DataTable常见用法

DataTable dt_new= new DataTable();

dt_new.Columns.Add("column1", typeof(string));
dt_new.Columns.Add("column2", typeof(string));
dt_new.Columns.Add("column3", typeof(Double));

DataRow dr = dt_new.NewRow();
dr["column1"] = column1_value;
dr["column2"] = column2_value;
dr["column3"]=Convert.ToDouble(column3_value);
//将DataRow加入数据表
dt_new.Rows.Add(dr);

//复制DataTable 结构不包含数据
DataTable dt_temp = dt_new.Clone();

dt_temp .Columns["column1"].DataType = typeof(Double);//更改列数据类型

//填充数据
foreach (DataRow row in dt_new.Rows)
{
if (!row["column1"].ToString().Equals("NULL"))
{
dte_temp.ImportRow(row);//添加进新表
}

}

DataTable dt_tmp = new DataTable();
//注意，字符串值要加引号
string filterExpression = "device_id= '" + task.CompareDeviceID+"'";

DataRow[] arrayDR = dt_fix.Select(filterExpression);
if (arrayDR != null)
{
//转换成DataTable
dt_tmp = ToDataTable(arrayDR);
}

//dt_fix和dt_fix_temp 为DataTable
dt_fix.DefaultView.Sort = "device_id asc";//根据ID排序 升序,desc降序
dt_fix_temp = dt_fix.DefaultView.ToTable();