ASP.NET Tutorial/ADO.net Database/OdbcCommand — различия между версиями

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Текущая версия на 11:56, 26 мая 2010

Create OdbcCommand and execute it (C#)

<%@ Page Language="C#" %>
<%@ import Namespace="System.Data" %>
<%@ import Namespace="System.Data.Odbc" %>
<script runat="server">
    void Page_Load(object sender, EventArgs e) {
        if (!Page.IsPostBack)
        {
            string ConnectionString = ConfigurationSettings.AppSettings["MySQLConnectString"];
            OdbcConnection myConnection = new OdbcConnection(ConnectionString);
    
            try{
                string CommandTextPublisher = "SELECT PublisherID, PublisherName FROM Publisher";
                OdbcCommand myCommandPublishers = new OdbcCommand(CommandTextPublisher, myConnection);
    
                myConnection.Open();
    
                DropDownList1.DataSource = myCommandPublishers.ExecuteReader();
                DropDownList1.DataTextField = "PublisherName";
                DropDownList1.DataValueField = "PublisherID";
                DropDownList1.DataBind();
                DropDownList1.Items.Insert(0, new ListItem("-- All Publishers --", "0"));
            } catch (Exception ex){
                throw(ex);
            } finally{
                myConnection.Close();
            }
        }
    }
    
    void ApplyFilter_Click(Object sender, EventArgs e) {
        string ConnectionString = ConfigurationSettings.AppSettings["MySQLConnectString"];
        OdbcConnection myConnection = new OdbcConnection(ConnectionString);
    
        try{
            string CommandTextBooks = "SELECT Book.BookTitle, Publisher.PublisherName FROM Book INNER JOIN Publisher on Book.BookPublisherID = Publisher.PublisherID";
            string filterValue = DropDownList1.SelectedValue;
            if (filterValue != "0")
                CommandTextBooks += " WHERE Book.BookPublisherID = " + filterValue;
            CommandTextBooks+=" ORDER BY Book.BookTitle";
            OdbcCommand myCommandBooks = new OdbcCommand(CommandTextBooks, myConnection);
            myConnection.Open();
            DataGrid1.DataSource = myCommandBooks.ExecuteReader();
            DataGrid1.DataBind();
        } catch (Exception ex){
            throw(ex);
        } finally{
            myConnection.Close();
        }
    }
</script>
<html>
<head>
</head>
<body>
    <form runat="server">
        
            Select a Publisher: 
            <asp:DropDownList id="DropDownList1" runat="server"></asp:DropDownList>
            &nbsp; 
            <asp:Button id="Button1" onclick="ApplyFilter_Click" runat="server" Text="Show Titles"></asp:Button>
        
        <asp:datagrid id="DataGrid1" runat="server" CellSpacing="1" GridLines="None" CellPadding="3" BackColor="White" ForeColor="Black" EnableViewState="False">
            <HeaderStyle font-bold="True" forecolor="white" backcolor="#4A3C8C"></HeaderStyle>
            <ItemStyle backcolor="#DEDFDE"></ItemStyle>
        </asp:datagrid>
    </form>
</body>
</html>
File: Web.config
<configuration>
    <appSettings>
        <add key="MySQLConnectString" value="driver={MySQL ODBC 3.51 Driver};server=localhost;database=Books;uid=YourID;pwd=letmein;" />
    </appSettings>
</configuration>


OdbcCommand and OdbcParameter

<%@ Page Language="C#" %>
<%@ import Namespace="System.Data" %>
<%@ import Namespace="System.Data.Odbc" %>
<script runat="server">
    void Page_Load(object sender, EventArgs e) {
        if (!Page.IsPostBack)
        {
            OdbcConnection myConnection = new OdbcConnection(@"driver={MySQL ODBC 3.51 Driver};server=localhost;database=books;uid=user;pwd=letmein;");
    
            try{
                string CommandTextPublisher = "SELECT PublisherID, PublisherName FROM Publisher";
                OdbcCommand myCommandPublishers = new OdbcCommand(CommandTextPublisher, myConnection);
    
                myConnection.Open();
    
                DropDownList1.DataSource = myCommandPublishers.ExecuteReader();
                DropDownList1.DataTextField = "PublisherName";
                DropDownList1.DataValueField = "PublisherID";
                DropDownList1.DataBind();
                DropDownList1.Items.Insert(0, new ListItem("-- All Publishers --", "0"));
            } catch (Exception ex){
                throw(ex);
            } finally{
                myConnection.Close();
            }
        }
    }
    
    void ApplyFilter_Click(Object sender, EventArgs e) {
        OdbcConnection myConnection = new OdbcConnection(@"driver={MySQL ODBC 3.51 Driver};server=localhost;database=books;uid=user;pwd=letmein;");
    
        try{
            string CommandTextBooks = "SELECT Book.BookTitle, Publisher.PublisherName FROM Book INNER JOIN Publisher on Book.BookPublisherID = Publisher.PublisherID WHERE ?=0 OR Book.BookPublisherID=? ORDER BY Book.BookTitle";
            OdbcCommand myCommandBooks = new OdbcCommand(CommandTextBooks, myConnection);
    
            OdbcParameter myParameter1 = new OdbcParameter();
            myParameter1.ParameterName = "@pub1";
            myParameter1.OdbcType = OdbcType.Int;
            myParameter1.Value = DropDownList1.SelectedValue;
            myCommandBooks.Parameters.Add (myParameter1);
    
            OdbcParameter myParameter2 = new OdbcParameter();
            myParameter2.ParameterName = "@pub2";
            myParameter2.OdbcType = OdbcType.Int;
            myParameter2.Value = DropDownList1.SelectedValue;
            myCommandBooks.Parameters.Add (myParameter2);
    
            myConnection.Open();
    
            DataGrid1.DataSource = myCommandBooks.ExecuteReader();
            DataGrid1.DataBind();
        } catch (Exception ex){
            throw(ex);
        } finally{
            myConnection.Close();
        }
    }
</script>
<html>
<head>
</head>
<body>
    <form runat="server">
        
            Select a Publisher: 
            <asp:DropDownList id="DropDownList1" runat="server"></asp:DropDownList>
            &nbsp; 
            <asp:Button id="Button1" onclick="ApplyFilter_Click" runat="server" Text="Show Titles"></asp:Button>
        
        <asp:datagrid id="DataGrid1" runat="server" EnableViewState="False">
            <HeaderStyle font-bold="True" forecolor="white" backcolor="#4A3C8C"></HeaderStyle>
            <ItemStyle backcolor="#DEDFDE"></ItemStyle>
        </asp:datagrid>
    </form>
</body>
</html>
Источник — «http://nfex.ru/index.php?title=ASP.NET_Tutorial/ADO.net_Database/OdbcCommand&oldid=2730»