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  • WPF简单的数据库查询

     做一个简单WPF连接数据库的

    控件类型和名称:DataGrid:dataGrid          Button1  :Button1              Button:   Button2               TextBox : txtuserName

     在引用App.config写数据库的连接字符串

    <?xml version="1.0" encoding="utf-8" ?>
    <configuration>
        <startup> 
            <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
        </startup>
       <appSettings>
        <!--数据库连接字符串-->
        <add key ="ConnString" value ="Data Source=.;initial Catalog=educ; user=sa; Password=123456;Pooling=true" />
      </appSettings>
    </configuration>
    <add key ="ConnString" value ="Data Source=.;initial Catalog=educ; user=sa; Password=123456;Pooling=true" />
    Data Source=.表示本机,可以写ip地址 initial Catalog=数据库名 user=用户名 Password=密码;

    写一个DataBaseHelper的数据库类
     1 namespace _03连接数据库
     2 {
     3     class DataBaseHelper
     4     {
     5 
     6         /// 数据库打开连接的方法
     7         /// 
     8         /// </summary>
     9         /// <returns></returns>
    10         public static SqlConnection getSqlConnection()
    11         {
    12             SqlConnection sqlConnection = new SqlConnection();          
    13             try
    14             {
    15                  //获取数据库字符串
    16                 sqlConnection.ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnString"];           
    17                 sqlConnection.Open();
    18                 sqlConnection.Close();
    19             }
    20             catch 
    21             {
    22 
    23                 throw new Exception("无法连接数据库服务器"); 
    24             }
    25           
    26             return sqlConnection;
    27         }
    28 
    29         /// sql增删改的方法
    30         /// 
    31         /// </summary>
    32         /// <param name="sqlstr"></param>
    33         /// <returns></returns>
    34         public static int GetNonQueryEffect(string sqlstr)
    35         {        
    36             SqlConnection sqlConnection = new SqlConnection();
    37             try
    38             {
    39                 sqlConnection.Open();
    40                 //创建要执行的语句
    41                 SqlCommand cmd = new SqlCommand(sqlstr, sqlConnection);
    42                 return cmd.ExecuteNonQuery();//返回执行语句中的错误
    43             }
    44             catch (Exception ex)
    45             {
    46                 throw new Exception(ex.ToString());
    47                 
    48             }
    49             finally
    50             {
    51                 sqlConnection.Close();
    52                 sqlConnection.Dispose();//释放资源
    53             }
    54           
    55         }
    56 
    57          ///  读取数据的的方法    
    58          ///  
    59          /// </summary>
    60          /// <param name="sqlstr"></param>
    61          /// <returns></returns>
    62         public static DataSet GetDataset(string sqlstr)
    63         {
    64             SqlConnection conn = getSqlConnection();
    65             try
    66             {
    67                 conn.Open();//打开数据库连接
    68                 SqlDataAdapter sda = new SqlDataAdapter(sqlstr ,conn );//更新数据库的命令
    69                 DataSet ds = new DataSet();
    70                 sda.Fill(ds);//填充
    71                 return ds;
    72             }
    73             catch (Exception ex)
    74             {
    75 
    76                 throw new Exception(ex.ToString ());
    77             }
    78             finally
    79             {
    80                 conn.Close();
    81                 conn.Dispose();
    82             }
    83         }    
    84     }
    85 }

     按键的代码

     1   private void Button_Click_1(object sender, RoutedEventArgs e)
     2         {
     3             string str = "select *FROM student";//查询的语句
     4             dataGrid.ItemsSource = DataBaseHelper.GetDataset(str).Tables[0].DefaultView;
     5             
     6         }
     7         private void Button_Click_2(object sender, RoutedEventArgs e)
     8         {
     9             if (txtuserName.Text.Trim()== " ")
    10             {
    11                 return;
    12             }
    13             string strr = string.Format("select *FROM student where sname='{0}'", txtuserName.Text);
    14             dataGrid.ItemsSource = DataBaseHelper.GetDataset(strr).Tables[0].DefaultView;
    15         }
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  • 原文地址:https://www.cnblogs.com/enduo/p/7793907.html
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