sqlhelper.cs

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using System;
using System.Data;
using System.Data.SqlClient;
using System.Collections;
using System.Xml;

namespace corInfMan.Utility
{

	/// <summary>
	/// The SqlHelper class is intended to encapsulate high performance, 
	/// scalable best practices for common uses of SqlClient.
	/// </summary>
	public abstract class SQLHelper 
    {




        /* *********************************数据库连接字符串*******************************************
         * SQLServer 2005:
         *      Data Source=192.168.1.110;Initial Catalog=mydoc;Integrated Security=True
         *      Data Source=192.168.1.110;Initial Catalog=mydoc;Integrated Security=True
         * Access:
         *      Provider=Microsoft.Jet.OLEDB.4.0;Data Source=F:\MyDev\myArticle\myarticle.mdb;Persist Security Info=True;Jet OLEDB:Database Password=dlxdlx
         * SQLServer 2000:
         *      server=127.0.0.1;uid=sa;pwd=sql;database=dlx
         * *******************************************************************************************/

        //reading connection string from app.config file in VS2008
        //public static string connectionString = Properties.Settings.Default.ConnectionString;
        const string conStr = "Data Source=(local);Initial Catalog=dlxcorInfMan;Persist Security Info=True;User ID=sa;Password=sql";
        public static string connectionString = conStr;


        # region 获取指定表号SingleID:GetMaxID(字段名，表名)
        /// <summary>
        /// 重载方法GetMaxID给定表名、字段名获得最大值
        /// </summary>
        /// <param name="FieldName">字段名</param>
        /// <param name="TableName">表名</param>
        /// <returns></returns>
        public static int GetMaxID(string FieldName, string TableName)
        {
            #region 下面代码适应与Access等不能支持存储过程的数据库

            string strsql = "select max(" + FieldName + ")+1 from " + TableName;
            object obj = GetSingle(strsql);
            if (obj == null)
            {
                return 1;
            }
            else
            {
                return int.Parse(obj.ToString());
            }
            #endregion


        }
        #endregion

        #region 公用方法


        public static bool Exists(string strSql, params SqlParameter[] cmdParms)
		{
			object obj = GetSingle(strSql, cmdParms);
			//int cmdresult;
			if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
			{
				//cmdresult = 0;
                return false;
			}
			else
			{
                //cmdresult = 1;
                return true;
			}
            //if (cmdresult == 0)
            //{
            //    return false;
            //}
            //else
            //{
            //    return true;
            //}
		}
		#endregion

		#region  执行简单SQL语句

		/// <summary>
		/// 执行SQL语句，返回影响的记录数
		/// </summary>
		/// <param name="SQLString">SQL语句</param>
		/// <returns>影响的记录数</returns>
		public static int ExecuteSql(string SQLString)
		{
			using (SqlConnection connection = new SqlConnection(connectionString))
			{				
				using (SqlCommand cmd = new SqlCommand(SQLString,connection))
				{
                    try
                    {
                        connection.Open();
                        int rows = cmd.ExecuteNonQuery();
                        return rows;
                    }
                    catch (System.Data.SqlClient.SqlException E)
                    {
                        connection.Close();
                        throw new Exception(E.Message);
                    }
				}				
			}
		}
		

		/// <summary>
		/// 执行带一个存储过程参数的的SQL语句。
		/// </summary>
		/// <param name="SQLString">SQL语句</param>
		/// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
		/// <returns>影响的记录数</returns>
		public static int ExecuteSql(string SQLString,string content)
		{				
			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				SqlCommand cmd = new SqlCommand(SQLString,connection);		
				System.Data.SqlClient.SqlParameter  myParameter = new System.Data.SqlClient.SqlParameter ( "@content", SqlDbType.NText);
				myParameter.Value = content ;
				cmd.Parameters.Add(myParameter);
				try
				{
					connection.Open();
					int rows=cmd.ExecuteNonQuery();
					return rows;
				}
				catch(System.Data.SqlClient.SqlException E)
				{				
					throw new Exception(E.Message);
				}
				finally
				{
					cmd.Dispose();
					connection.Close();
				}	
			}
		}		
		/// <summary>
		/// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
		/// </summary>
		/// <param name="strSQL">SQL语句</param>
		/// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
		/// <returns>影响的记录数</returns>
		public static int ExecuteSqlInsertImg(string strSQL,byte[] fs)
		{		
			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				SqlCommand cmd = new SqlCommand(strSQL,connection);	
				System.Data.SqlClient.SqlParameter  myParameter = new System.Data.SqlClient.SqlParameter ( "@fs", SqlDbType.Image);
				myParameter.Value = fs ;
				cmd.Parameters.Add(myParameter);
				try
				{
					connection.Open();
					int rows=cmd.ExecuteNonQuery();
					return rows;
				}
				catch(System.Data.SqlClient.SqlException E)
				{				
					throw new Exception(E.Message);
				}
				finally
				{
					cmd.Dispose();
					connection.Close();
				}				
			}
		}
		
		/// <summary>
		/// 执行一条计算查询结果语句，返回查询结果（object）。
		/// </summary>
		/// <param name="SQLString">计算查询结果语句</param>
		/// <returns>查询结果（object）</returns>
		public static object GetSingle(string SQLString)
		{
			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				using(SqlCommand cmd = new SqlCommand(SQLString,connection))
				{
					try
					{
						connection.Open();
						object obj = cmd.ExecuteScalar();
						if((Object.Equals(obj,null))||(Object.Equals(obj,System.DBNull.Value)))
						{					
							return null;
						}
						else
						{
							return obj;
						}				
					}
					catch(System.Data.SqlClient.SqlException e)
					{						
						connection.Close();
						throw new Exception(e.Message);
					}	
				}
			}
		}
		/// <summary>
		/// 执行查询语句，返回SqlDataReader
		/// </summary>
		/// <param name="strSQL">查询语句</param>
		/// <returns>SqlDataReader</returns>
		public static SqlDataReader ExecuteReader(string strSQL)
		{
			SqlConnection connection = new SqlConnection(connectionString);			
			SqlCommand cmd = new SqlCommand(strSQL,connection);				
			try
			{
				connection.Open();	
				SqlDataReader myReader = cmd.ExecuteReader();
				return myReader;
			}
			catch(System.Data.SqlClient.SqlException e)
			{								
				throw new Exception(e.Message);
			}			
			
		}		
		/// <summary>
		/// 执行查询语句，返回DataSet
		/// </summary>
		/// <param name="SQLString">查询语句</param>
		/// <returns>DataSet</returns>
		public static DataSet Query(string SQLString)
		{
			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				DataSet ds = new DataSet();
				try
				{
					connection.Open();
					SqlDataAdapter command = new SqlDataAdapter(SQLString,connection);				
					command.Fill(ds,"ds");
				}
				catch(System.Data.SqlClient.SqlException ex)
				{				
					throw new Exception(ex.Message);                    
                    //return null;
				}			
				return ds;
			}			
		}



		/// <summary>
		/// 执行查询语句，返回DataSet-分页显示
		/// </summary>
		/// <param name="SQLString">查询语句</param>
		/// <returns>DataSet</returns>
		public static DataSet Query(string SQLString,int startpage,int pagesize)
		{
			using (SqlConnection connection = new SqlConnection(connectionString))
			{
				DataSet ds = new DataSet();
				try