using System;
using System.Collections;

namespace HRManager.DataAccessHelper
{
	/// <summary>
	/// SQLString 的摘要說明。
	/// </summary>
	public class SqlStringConstructor
	{
		/// <summary>
		/// 公有靜態方法，將文本轉換成適合在Sql語句里使用的字符串。
		/// </summary>
		/// <returns>轉換后文本</returns>	
		public static String GetQuotedString(String pStr)
		{
			return ("'" + pStr.Replace("'","''") + "'");
		}

		/// <summary>
		/// 根據條件哈希表,構造SQL語句中的AND條件子句
		/// </summary>
		/// <param name="conditionHash">條件哈希表</param>
		/// <returns>AND關系條件子句</returns>
        public static String GetConditionClause(Hashtable queryItems)
        {

            int Count = 0;
            String Where = "";

            //根據哈希表，循環生成條件子句
            foreach (DictionaryEntry item in queryItems)
            {
                if (Count == 0)
                    Where = " Where ";
                else
                    Where += " And ";

                //根據查詢列的數據類型，決定是否加單引號
                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;
        }
	}
}