sqlstring.cs

精通SQL Server2005项目开发

using System;
using System.Collections;

namespace HRManager.DataAccessHelper
{
	/// <summary>
	/// SQLString 的摘要说明。
	/// </summary>
	public class SqlStringConstructor
	{
		/// <summary>
		/// 公有静态方法，将文本转换成适合在Sql语句里使用的字符串。
		/// </summary>
		/// <returns>转换后文本</returns>	
		public static String GetQuotedString(String pStr)
		{
			return ("'" + pStr.Replace("'","''") + "'");
		}

		/// <summary>
		/// 根据条件哈希表,构造SQL语句中的AND条件子句
		/// </summary>
		/// <param name="conditionHash">条件哈希表</param>
		/// <returns>AND关系条件子句</returns>
        public static String GetConditionClause(Hashtable queryItems)
        {

            int Count = 0;
            String Where = "";

            //根据哈希表，循环生成条件子句
            foreach (DictionaryEntry item in queryItems)
            {
                if (Count == 0)
                    Where = " Where ";
                else
                    Where += " And ";

                //根据查询列的数据类型，决定是否加单引号
                if (item.Value.GetType().ToString() == "System.String" || item.Value.GetType().ToString() == "System.DateTime")
                {
                    Where += item.Key.ToString()
                        + " Like "
                        + SqlStringConstructor.GetQuotedString("%"
                        + item.Value.ToString()
                        + "%");
                }
                else
                {
                    Where += item.Key.ToString() + "= " + item.Value.ToString();
                }
                Count++;
            }
            return Where;
        }
	}
}