黑马程序员+ADO.Net基础(下)

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12  优化导入数据
        /// <summary>

/// 优化导入操作

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void button3_Click(object sender, EventArgs e)

{

OpenFileDialog ofd = new OpenFileDialog();

if (ofd.ShowDialog()==DialogResult.OK)

{//创建一次连接

using (SqlConnection conn=new SqlConnection(conStr))

{

conn.Open();

using (SqlCommand cmd=conn.CreateCommand())

{

cmd.CommandText = "insert into T_Person values(@Name,@Age)";

using (FileStream stream = File.OpenRead(ofd.FileName))

{

using (StreamReader reader=new StreamReader(stream))

{

string lines = null;

while ((lines=reader.ReadLine())!=null)

{

string[] line = lines.Split('|');

string name = line[0];

int age = Convert.ToInt32(line[1]);

cmd.Parameters.Clear();//重要！

cmd.Parameters.Add(new SqlParameter("@Name",name));

cmd.Parameters.Add(new SqlParameter("@Age", age));

cmd.ExecuteNonQuery();

}

MessageBox.Show("导入数据成功！");

}

}

}

}

}

}

13  省市联级（DisplayMember  ComoBox加载时要显示的字段; DropDownStyle  ComoBox 只能下拉菜单;）      
       string conStr = @"Data Source=ZHANGLIANG\SQLEXPRESS;Initial Catalog=MyDB;Integrated Security=True";

/// <summary>

/// 加载省

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void Form1_Load(object sender, EventArgs e)

{

using (SqlConnection conn=new SqlConnection(conStr))

{

conn.Open();

using (SqlCommand cmd=conn.CreateCommand())

{

cmd.CommandText = "select * from promary ";

using (SqlDataReader reader=cmd.ExecuteReader())

{

while (reader.Read())

{

Promary promary = new Promary();

promary.ProID = reader.GetInt32(reader.GetOrdinal("proID"));

promary.ProName = reader.GetString(reader.GetOrdinal("proName"));

cmbpromary.Items.Add(promary);

}

}

}

}

}

/// <summary>

/// 加载市

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void cmbpromary_SelectedIndexChanged(object sender, EventArgs e)

{

City city=new City();

Promary promary = (Promary)cmbpromary.SelectedItem;

int i=promary.ProID;

using (SqlConnection conn=new SqlConnection(conStr))

{

conn.Open();

using (SqlCommand cmd=conn.CreateCommand())

{

cmd.CommandText = string.Format("select * from city where proID='{0}'",promary.ProID);

using (SqlDataReader reader=cmd.ExecuteReader())

{

cmbcity.Items.Clear();

while (reader.Read())

{

city.CityID = reader.GetInt32(reader.GetOrdinal("cityID"));

city.CityName = reader.GetString(reader.GetOrdinal("cityName"));

cmbcity.Items.Add(city);

}

}

}

}

}

}

class City {

public int CityID { get; set; }

public string CityName { get; set; }

}

class Promary {

public int ProID { get; set; }

public string ProName { get; set; }

}

14 读取配置中的连接字符串
  <connectionStrings>

<add name="ConnectionStr" connectionString=@"Data Source=ZHANGLIANG\SQLEXPRESS;Initial Catalog=MyDB;Integrated Security=True"/>

//获取配置连接字符串

</connectionStrings>

            stringconstr=ConfigurationManager.ConnectionStrings["ConnectionStr"].ConnectionString

 

15 号码归属地查询
private string constr = ConfigurationManager.ConnectionStrings["newconString"].ConnectionString;

private void button1_Click(object sender, EventArgs e)

{

using (SqlConnection conn=new SqlConnection(constr))

{

conn.Open();

using (SqlCommand cmd=conn.CreateCommand())

{

cmd.CommandText = "delete from T_Numbers";

cmd.ExecuteNonQuery();

}

}

FolderBrowserDialog fbd = new FolderBrowserDialog();

fbd.SelectedPath = @"F:\c#\c#基础\手机号码归属地";

if (fbd.ShowDialog() == DialogResult.OK)

{

string path = fbd.SelectedPath;

string[] files = Directory.GetFiles(path, "*.txt", SearchOption.AllDirectories);

using (SqlConnection conn = new SqlConnection(constr))

{

conn.Open();

using (SqlCommand cmd = conn.CreateCommand())

{

cmd.CommandText = "insert into T_Numbers values(@StartNumber,@EndNumber,@Name)";

foreach (var file in files)

{

string fileName = Path.GetFileNameWithoutExtension(file);

string[] lines = File.ReadAllLines(file, Encoding.Default);

foreach (var line in lines)

{

string[] str = line.Split('-');

string startNumber = str[0];

string endNumber = str[1];

string city = str[2];

cmd.Parameters.Clear();

cmd.Parameters.Add("@StartNumber", startNumber);

cmd.Parameters.Add("@EndNumber", endNumber);

cmd.Parameters.Add("@Name", fileName + city);

cmd.ExecuteNonQuery();

}

}

}

}

}

}

/// <summary>

/// 号码所属地查询

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void button2_Click(object sender, EventArgs e)

{

string No = txtNumber.Text.Trim();

using (SqlConnection conn=new SqlConnection(constr))

{

conn.Open();

using (SqlCommand cmd=conn.CreateCommand())

{

cmd.CommandText = "select * from T_Numbers where startnumber<=@No and @No<=endnumber ";

cmd.Parameters.Add("@No",No);

using (SqlDataReader reader=cmd.ExecuteReader())

{

while (reader.Read())

{

MessageBox.Show(reader.GetString(reader.GetOrdinal("name")));

}

}

}

}

}

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