学习笔记之DataTable

思维导图

知识点

创建DataTable数据表

创建一个表名为yp的数据表：

DataTable NewTable = new DataTable(yp);

创建DataTable对象的实例yp

DataTable workTable = new DataTable("yp");

添加DataTable列(Columns属性)

DataTable workTable = new DataTable("Customers");

DataColumn workCol = workTable.Columns.Add("CustID");

workTable.Columns.Add("CustLName");

workTable.Columns.Add("CustFName");

workTable.Columns.Add("Purchases");

添加DataTable行

DataTable CustomersTable = new DataTable("Customers ");

DataRow arow = CustomersTable.NewRow();

arow[ColumnName] = DataValue;

CustomersTable.Rows.Add(arow);

新建行的赋值

DataRow dr = dt.NewRow();

dr[0] = "张三";//通过索引赋值

dr["column1"] = DateTime.Now;

dt.Rows[0][0] = "张三"; //通过索引赋值

dt.Rows[0]["column1"] = DateTime.Now;

取值

string name=dt.Rows[0][0].ToString();

string time=dt.Rows[0]["column1"].ToString();

案例代码如下：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace 药品工作站
{
    public partial class 追加入库 : Form
    {
        public 追加入库()
        {
            InitializeComponent();
            this.StartPosition = FormStartPosition.CenterScreen;                                             
            this.dgv.BackgroundColor = Color.White;                                                  
            this.dgv.AutoSizeColumnsMode =
                DataGridViewAutoSizeColumnsMode.AllCells;
        }private void button2_Click(object sender, EventArgs e)
        {
            SqlConnection sqlConnection = new SqlConnection();                                              
            sqlConnection.ConnectionString =
                "Server=(local);Database=药品工作站管理系统;Integrated Security=sspi";                             
            SqlCommand sqlCommand = new SqlCommand();                                                       
            sqlCommand.Connection = sqlConnection;                                                          
            sqlCommand.CommandText = "SELECT * FROM 药品入库表;";                                           
            SqlDataAdapter sqlDataAdapter = new SqlDataAdapter();                                           
            sqlDataAdapter.SelectCommand = sqlCommand;                                                      
            DataTable ypTable = new DataTable();                                                       
            sqlConnection.Open();                                                                         
            sqlDataAdapter.Fill(ypTable);                                                              
            sqlConnection.Close();                                                                         
            this.dgv.DataSource = ypTable; 
        }private void button3_Click_1(object sender, EventArgs e)
        {
            if (this.dgv.RowCount > 0)                                                               
            {
                DataRow                                                                                     
                currentypRow = ((DataRowView)this.dgv.CurrentRow.DataBoundItem).Row;          
                no.Text =Convert.ToString(currentypRow["入库编号"]);                                           
                ypno.Text = Convert.ToString(currentypRow["药品编号"]);
                number.Text = Convert.ToString(currentypRow["入库数量"]);
                time.Text = Convert.ToString(currentypRow["入库时间"]);
                man.Text = Convert.ToString(currentypRow["操作员"]);
            } 
        }
        private void button1_Click(object sender, EventArgs e)
        {
            if (this.no.Text.Trim() == "")                                                     
            {
                MessageBox.Show("编号不能为空！");                                                   
                this.no.Focus();                                                                
                return;                                                                               
            }
            if (this.ypno.Text.Trim() == "")                                                    
            {
                MessageBox.Show("药品编号不能为空！");                                                     
                this.ypno.Focus();                                                              
                return;                                                                                
            }
            if (this.number.Text.Trim() == "")                                                     
            {
                MessageBox.Show("数量不能为空！");                                                   
                this.number.Focus();                                                                
                return;                                                                               
            }
            if (this.time.Text.Trim() == "")                                                      
            {
                MessageBox.Show("时间不能为空！");                                                    
                this.time.Focus();                                                               
                return;                                                                                 
            }
            if (this.man.Text.Trim() == "")                                                     
            {
                MessageBox.Show("操作员不能为空！");                                                    
                this.man.Focus();                                                               
                return;                                                                                 
            }
            SqlConnection sqlConnection = new SqlConnection();                                             
            sqlConnection.ConnectionString =
            "Server=(local);Database=药品工作站管理系统;Integrated Security=sspi";                            
            SqlCommand sqlCommand = new SqlCommand();                                      
            sqlCommand.Connection = sqlConnection;
            SqlCommand updateCommand = new SqlCommand();                                                    
            updateCommand.Connection = sqlConnection;                                                       
            updateCommand.CommandText =                                                                     
                "UPDATE 药品入库表"
                + " SET 入库编号=@入库编号,药品编号=@药品编号,入库数量=@入库数量,入库时间=@入库时间,操作员=@操作员"
                + " WHERE 采购编号=@Old采购编号;";
            updateCommand.Parameters.Add("@入库编号", SqlDbType.Int, 0, this.no.Text.Trim());                               
            updateCommand.Parameters.Add("@药品编号", SqlDbType.Int, 0, this.ypno.Text.Trim());
            updateCommand.Parameters.Add("@入库数量", SqlDbType.Int, 0, this.number.Text.Trim());
            updateCommand.Parameters.Add("@入库时间", SqlDbType.Int, 0, time.ToString());
            updateCommand.Parameters.Add("@操作员", SqlDbType.Char, 0, this.man.Text.Trim());
            SqlDataAdapter sqlDataAdapter = new SqlDataAdapter();                         
            sqlDataAdapter.UpdateCommand = updateCommand;
            DataTable Table1 = (DataTable)this.dgv.DataSource;                                
            sqlConnection.Open();                                                                           
            int rowAffected = sqlDataAdapter.Update(Table1);                                      
            sqlConnection.Close();                                                                        
            MessageBox.Show("追加成功");
          }
        }
    }

结果如下：