DatabaseOper/SQLHelper.cs

这里只显示每个文件的开头 60 行。登录后可以解锁完整代码。

微信扫码关注公众号，代码整理好后第一时间通知你。

// ===============================================================================
// 本例程示范了SqlHelper和SqlHelperParameterCache类的执行.

using System; 
using System.Data;
using System.Xml;
using System.Data.SqlClient;
using System.Collections;
//51-aspx
namespace Microsoft.ApplicationBlocks.Data
{
	/// <summary>	
        /// SqlHelper类意在综合SqlClient一般使用中的高性能和最好的应用能力.
	/// </summary>
    public sealed class SqlHelper
    {
        #region private utility methods & constructors

        // Since this class provides only static methods, make the default constructor private to prevent 
        // instances from being created with "new SqlHelper()"
        // 因为本类只提供静态方法，从而使得默认的私有构建器（constructor）防止由"new SqlHelper()"来创建实例.

        private SqlHelper() {}

        /// <summary>
        /// This method is used to attach array of SqlParameters to a SqlCommand.
        /// 
        /// 本方法用于将SqlParameters参数集赋予SqlCommand.
        /// This method will assign a value of DbNull to any parameter with a direction of
        /// InputOutput and a value of null.  
        /// 本方法将一个DbNull值赋予任意的具有输入输出方向和null值的参数.
        /// 
        /// This behavior will prevent default values from being used, but
        /// this will be the less common case than an intended pure output parameter (derived as InputOutput)
        /// where the user provided no input value.
        /// 这样就可以避免默认值被使用，但是更多的情况是用户有意只提供输出参数而不提供输入值.
        /// 
        /// </summary>
        /// <param name="command">The command to which the parameters will be added</param>
        /// <param name="command">将被赋予参数的命令</param>
        /// 
        /// <param name="commandParameters">An array of SqlParameters to be added to command</param>
        /// <param name="commandParameters">将被赋予命令的SqlParameters参数集</param>
        /// 
        private static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters)
        {
			if( command == null ) throw new ArgumentNullException( "command" );
			if( commandParameters != null )
			{
				foreach (SqlParameter p in commandParameters)
				{
					if( p != null )
					{
						// Check for derived output value with no value assigned
                                                // 检测没有被赋值的输出值
						if ( ( p.Direction == ParameterDirection.InputOutput || 
							p.Direction == ParameterDirection.Input ) && 
							(p.Value == null))
						{
							p.Value = DBNull.Value;