知识大全 网购系统——通用数据库访问函数
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一 try…catch…finally结构 [csharp] using System; using System Data; using System Data SqlClient; using System Configuration; using System Collections Generic; using WestGarden Model; namespace WestGarden Web public partial class Default : System Web UI Page protected void Page_Load(object sender EventArgs e) IList<CategoryInfo> catogories = new List<CategoryInfo>() string connectionString = ConfigurationManager ConnectionStrings[ NetShopConnString ] ConnectionString; string cmdText = SELECT * FROM Category ; SqlCommand cmd = new SqlCommand() SqlConnection conn = new SqlConnection(connectionString) try cmd Connection = conn; cmd CommandType = CommandType Text; cmd CommandText = cmdText; conn Open() SqlDataReader rdr = cmd ExecuteReader() while (rdr Read()) CategoryInfo category = new CategoryInfo(rdr GetString( ) rdr GetString( ) rdr GetString( )) catogories Add(category) rdr Close() finally conn Close() ddlCategories DataSource = catogories; ddlCategories DataTextField = Name ; ddlCategories DataValueField = CategoryId ; ddlCategories DataBind() using System; using System Data; using System Data SqlClient; using System Configuration; using System Collections Generic; using WestGarden Model; namespace WestGarden Web public partial class Default : System Web UI Page protected void Page_Load(object sender EventArgs e) IList<CategoryInfo> catogories = new List<CategoryInfo>() string connectionString = ConfigurationManager ConnectionStrings[ NetShopConnString ] ConnectionString; string cmdText = SELECT * FROM Category ; SqlCommand cmd = new SqlCommand() SqlConnection conn = new SqlConnection(connectionString) try cmd Connection = conn; cmd CommandType = CommandType Text; cmd CommandText = cmdText; conn Open() SqlDataReader rdr = cmd ExecuteReader() while (rdr Read()) CategoryInfo category = new CategoryInfo(rdr GetString( ) rdr GetString( ) rdr GetString( )) catogories Add(category) rdr Close() finally conn Close() ddlCategories DataSource = catogories; ddlCategories DataTextField = Name ; ddlCategories DataValueField = CategoryId ; ddlCategories DataBind() 二 using()结构 [csharp] using System; using System Data; using System Data SqlClient; using System Configuration; using System Collections Generic; using WestGarden Model; namespace WestGarden Web public partial class Default : System Web UI Page protected void Page_Load(object sender EventArgs e) IList<CategoryInfo> catogories = new List<CategoryInfo>() string connectionString = ConfigurationManager ConnectionStrings[ NetShopConnString ] ConnectionString; string cmdText = SELECT * FROM Category ; SqlCommand cmd = new SqlCommand() [nextpage] //简单地说 using()结构等同于前面的try…finally结构 隐式关闭了conn using(SqlConnection conn = new SqlConnection(connectionString)) cmd Connection = conn; cmd CommandType = CommandType Text; cmd CommandText = cmdText; conn Open() SqlDataReader rdr = cmd ExecuteReader() while (rdr Read()) CategoryInfo category = new CategoryInfo(rdr GetString( ) rdr GetString( ) rdr GetString( )) catogories Add(category) rdr Close() ddlCategories DataSource = catogories; ddlCategories DataTextField = Name ; ddlCategories DataValueField = CategoryId ; ddlCategories DataBind() using System; using System Data; using System Data SqlClient; using System Configuration; using System Collections Generic; using WestGarden Model; namespace WestGarden Web public partial class Default : System Web UI Page protected void Page_Load(object sender EventArgs e) IList<CategoryInfo> catogories = new List<CategoryInfo>() string connectionString = ConfigurationManager ConnectionStrings[ NetShopConnString ] ConnectionString; string cmdText = SELECT * FROM Category ; SqlCommand cmd = new SqlCommand() //简单地说 using()结构等同于前面的try…finally结构 隐式关闭了conn using(SqlConnection conn = new SqlConnection(connectionString)) cmd Connection = conn; cmd CommandType = CommandType Text; cmd CommandText = cmdText; conn Open() SqlDataReader rdr = cmd ExecuteReader() while (rdr Read()) CategoryInfo category = new CategoryInfo(rdr GetString( ) rdr GetString( ) rdr GetString( )) catogories Add(category) rdr Close() ddlCategories DataSource = catogories; ddlCategories DataTextField = Name ; ddlCategories DataValueField = CategoryId ; ddlCategories DataBind() 三 通用的数据库访问函数 [csharp] using System; using System Data; using System Data SqlClient; using System Configuration; using System Collections Generic; using WestGarden Model; namespace WestGarden Web public partial class Default : System Web UI Page protected void Page_Load(object sender EventArgs e) IList<CategoryInfo> catogories = new List<CategoryInfo>() string connectionString = ConfigurationManager ConnectionStrings[ NetShopConnString ] ConnectionString; string cmdText = SELECT * FROM Category ; SqlDataReader rdr = ExecuteReader(connectionString CommandType Text cmdText) while (rdr Read()) CategoryInfo category = new CategoryInfo(rdr GetString( ) rdr GetString( ) rdr GetString( )) catogories Add(category) rdr Close() ddlCategories DataSource = catogories; ddlCategories DataTextField = Name ; ddlCategories DataValueField = CategoryId ; ddlCategories DataBind() public static SqlDataReader ExecuteReader(string connectionString CommandType cmdType string cmdText) SqlCommand cmd = new SqlCommand() SqlConnection conn = new SqlConnection(connectionString) try cmd Connection = conn; cmd CommandType = cmdType; cmd CommandText = cmdText; conn Open() [nextpage] //如果创建了 SqlDataReader 并将 CommandBehavior 设置为 CloseConnection //则关闭 SqlDataReader 会自动关闭此连接 SqlDataReader rdr = cmd ExecuteReader(CommandBehavior CloseConnection) return rdr; catch conn Close() throw; //finally // // conn Close() // using System; using System Data; using System Data SqlClient; using System Configuration; using System Collections Generic; using WestGarden Model; namespace WestGarden Web public partial class Default : System Web UI Page protected void Page_Load(object sender EventArgs e) IList<CategoryInfo> catogories = new List<CategoryInfo>() string connectionString = ConfigurationManager ConnectionStrings[ NetShopConnString ] ConnectionString; string cmdText = SELECT * FROM Category ; SqlDataReader rdr = ExecuteReader(connectionString CommandType Text cmdText) while (rdr Read()) CategoryInfo category = new CategoryInfo(rdr GetString( ) rdr GetString( ) rdr GetString( )) catogories Add(category) rdr Close() ddlCategories DataSource = catogories; ddlCategories DataTextField = Name ; ddlCategories DataValueField = CategoryId ; ddlCategories DataBind() public static SqlDataReader ExecuteReader(string connectionString CommandType cmdType string cmdText) SqlCommand cmd = new SqlCommand() SqlConnection conn = new SqlConnection(connectionString) try cmd Connection = conn; cmd CommandType = cmdType; cmd CommandText = cmdText; conn Open() //如果创建了 SqlDataReader 并将 CommandBehavior 设置为 CloseConnection //则关闭 SqlDataReader 会自动关闭此连接 SqlDataReader rdr = cmd ExecuteReader(CommandBehavior CloseConnection) return rdr; catch conn Close() throw; //finally // // conn Close() // [nextpage] 四 完善一下通用数据库访问函数 [csharp] using System; using System Data; using System Data SqlClient; using System Configuration; using System Collections Generic; using WestGarden Model; namespace WestGarden Web public partial class Default : System Web UI Page protected void Page_Load(object sender EventArgs e) IList<CategoryInfo> catogories = new List<CategoryInfo>() string connectionString = ConfigurationManager ConnectionStrings[ NetShopConnString ] ConnectionString; string cmdText = SELECT * FROM Category ; SqlDataReader rdr = ExecuteReader(connectionString CommandType Text cmdText null) while (rdr Read()) CategoryInfo category = new CategoryInfo(rdr GetString( ) rdr GetString( ) rdr GetString( )) catogories Add(category) rdr Close() ddlCategories DataSource = catogories; ddlCategories DataTextField = Name ; ddlCategories DataValueField = CategoryId ; ddlCategories DataBind() public static SqlDataReader ExecuteReader(string connectionString CommandType cmdType string cmdText params SqlParameter[] mandParameters) SqlCommand cmd = new SqlCommand() SqlConnection conn = new SqlConnection(connectionString) try //cmd Connection = conn; //cmd CommandType = cmdType; //cmd CommandText = cmdText; //conn Open() PrepareCommand(cmd conn null cmdType cmdText mandParameters) //如果创建了 SqlDataReader 并将 CommandBehavior 设置为 CloseConnection //则关闭 SqlDataReader 会自动关闭此连接 SqlDataReader rdr = cmd ExecuteReader(CommandBehavior CloseConnection) cmd Parameters Clear() return rdr; catch conn Close() throw; //finally // // conn Close() // private static void PrepareCommand(SqlCommand cmd SqlConnection conn SqlTransaction trans CommandType cmdType string cmdText SqlParameter[] cmdParms) if (conn State != ConnectionState Open) conn Open() cmd Connection = conn; cmd CommandText = cmdText; if (trans != null) cmd Transaction = trans; cmd CommandType = cmdType; if (cmdParms != null) foreach (SqlParameter parm in cmdParms) cmd Parameters Add(parm) using System; using System Data; using System Data SqlClient; using System Configuration; using System Collections Generic; using WestGarden Model; namespace WestGarden Web public partial class Default : System Web UI Page protected void Page_Load(object sender EventArgs e) [nextpage] IList<CategoryInfo> catogories = new List<CategoryInfo>() string connectionString = ConfigurationManager ConnectionStrings[ NetShopConnString ] ConnectionString; string cmdText = SELECT * FROM Category ; SqlDataReader rdr = ExecuteReader(connectionString CommandType Text cmdText null) while (rdr Read()) CategoryInfo category = new CategoryInfo(rdr GetString( ) rdr GetString( ) rdr GetString( )) catogories Add(category) rdr Close() ddlCategories DataSource = catogories; ddlCategories DataTextField = Name ; ddlCategories DataValueField = CategoryId ; ddlCategories DataBind() public static SqlDataReader ExecuteReader(string connectionString CommandType cmdType string cmdText params SqlParameter[] mandParameters) SqlCommand cmd = new SqlCommand() SqlConnection conn = new SqlConnection(connectionString) try //cmd Connection = conn; //cmd CommandType = cmdType; //cmd CommandText = cmdText; //conn Open() PrepareCommand(cmd conn null cmdType cmdText mandParameters) //如果创建了 SqlDataReader 并将 CommandBehavior 设置为 CloseConnection //则关闭 SqlDataReader 会自动关闭此连接 SqlDataReader rdr = cmd ExecuteReader(CommandBehavior CloseConnection) cmd Parameters Clear() return rdr; catch conn Close() throw; //finally // // conn Close() // private static void PrepareCommand(SqlCommand cmd SqlConnection conn SqlTransaction trans CommandType cmdType string cmdText SqlParameter[] cmdParms) [nextpage] if (conn State != ConnectionState Open) conn Open() cmd Connection = conn; cmd CommandText = cmdText; if (trans != null) cmd Transaction = trans; cmd CommandType = cmdType; if (cmdParms != null) foreach (SqlParameter parm in cmdParms) cmd Parameters Add(parm) 五 使用Reapter显示分类名称 窗体代码 [] <asp:Repeater ID= repCategories runat= server > <HeaderTemplate> <table cellspacing= border= > </HeaderTemplate> <ItemTemplate> <tr> <td> <asp:HyperLink runat= server ID= lnkCategory NavigateUrl= <%# string Format( ~/Items aspx?page= &categoryId= Eval( CategoryId )) %> Text= <%# Eval( Name ) %> /><asp:HiddenField runat= server ID= hidCategoryId Value= <%# Eval( CategoryId ) %> /> </td> </tr> </ItemTemplate> <FooterTemplate> </table> </FooterTemplate> </asp:Repeater> <asp:Repeater ID= repCategories runat= server > <HeaderTemplate> <table cellspacing= border= > </HeaderTemplate> <ItemTemplate> <tr> <td> <asp:HyperLink runat= server ID= lnkCategory NavigateUrl= <%# string Format( ~/Items aspx?page= &categoryId= Eval( CategoryId )) %> Text= <%# Eval( Name ) %> /><asp:HiddenField runat= server ID= hidCategoryId Value= <%# Eval( CategoryId ) %> /> </td> </tr> </ItemTemplate> <FooterTemplate> </table> </FooterTemplate> </asp:Repeater> 代码页绑定代码 [csharp] repCategories DataSource = catogories; repCategories DataBind() cha138/Article/program/net/201311/13382相关参考