c#学习（六）--dataTable使用_c# datatable

using MySql.Data.MySqlClient;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _05datable
{
    class Program
    {
        static void Main(string[] args)
        {
            //MySqlConnection connection = null;
            //connection = new MySqlConnection();
            //string str = ConfigurationManager.ConnectionStrings["conStri"].ConnectionString;
            //connection.ConnectionString = str;
            //1、独立创建与使用
            //DataTable dataTable = new DataTable();
            //dataTable.TableName = "news";
            //2、
            DataTable dataTable = new DataTable("news");
            DataColumn column1 = new DataColumn();
            column1.ColumnName = "id";
            column1.DataType = typeof(int);
            dataTable.Columns.Add(column1);
            dataTable.Columns.Add("title", typeof(string));//推荐添加一列
            dataTable.Columns.Add("contnt", typeof(string));
            dataTable.Columns.Add("insertime", typeof(DateTime));
            dataTable.Columns.Add("memberid", typeof(int));
            dataTable.PrimaryKey = new DataColumn[] { dataTable.Columns[0]};//设置主键
            dataTable.Constraints.Add(new UniqueConstraint(dataTable.Columns[1]));//定义约束
            //添加数据
            DataRow dataRow = dataTable.NewRow();
            dataRow["id"] = 3;
            dataRow["title"] = "标题";
            dataRow["contnt"] = "内容";
            dataRow["insertime"] = new DateTime();
            dataRow["memberid"] = 2;
            //这条数据并没有添加到datatable中 RowState  detached 不属于任何行孤立存在。
            dataTable.Rows.Add(dataRow);//添加到datatable里面；   在此之前 RowState  added
            dataRow["title"] = "修改";
            dataRow.AcceptChanges(); //RowState unchanged
            dataRow.Delete();  //RowState deleted
            dataRow.AcceptChanges();

            //dataTable.Clear(); //清除数据

           // dataTable.Copy();//复制架构和数据
           // dataTable.Clone();//只复制架构不包括数据
            Console.ReadKey();
        }
    }
}

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