打算写一个专门处理sql server 数据库类，不好的地方希望大神指点

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace TestDevExpressSolution
{
/// <summary>
/// Sql server 数据库操作类
/// Created by zhang.wenmin 2015-10-27
/// </summary>
public class SqlServerHelper
{
private static SqlServerHelper _Default;
public static SqlServerHelper Default
{
get
{
if (_Default == null)
_Default = new SqlServerHelper();
return _Default;
}
set
{
_Default = value;
}
}

#region 数据库配置项
private string _DBConfigStr = string.Empty;
public string DBConfigStr
{
get
{
return this._DBConfigStr;
}
set { this._DBConfigStr = value; }
}
#endregion

public SqlConnection Conn { get; set; }

public SqlConnection GetConnection()
{
if (string.IsNullOrWhiteSpace(this._DBConfigStr))
{
return null;
}
return new SqlConnection(this._DBConfigStr);
}
public object GetExecuteScalar(SqlConnection con, string sql, SqlParameter[] paramters, out string errorMsg)
{
object obj = null;
try
{
SqlCommand cmd = con.CreateCommand();
cmd.CommandText = sql;
cmd.Parameters.Clear();
if (paramters != null || paramters.Length > 0)
{
cmd.Parameters.AddRange(paramters);
}
con.Open();
obj = cmd.ExecuteScalar();
errorMsg = string.Empty;
cmd.Dispose();
}
catch (Exception ex)
{
errorMsg = ex.ToString();
}
finally
{
con.Close();
}
return obj;
}
public DataSet GetQueryData(SqlConnection con, string sql, SqlParameter[] paramters, out string errorMsg)
{
DataSet ds = new DataSet();
try
{
SqlCommand cmd = con.CreateCommand();
cmd.CommandText = sql;
cmd.Parameters.Clear();
if (paramters != null || paramters.Length > 0)
{
cmd.Parameters.AddRange(paramters);
}
con.Open();
SqlDataAdapter sda = new SqlDataAdapter(cmd);
sda.Fill(ds);
errorMsg = string.Empty;
cmd.Dispose();
}
catch (Exception ex)
{
errorMsg = ex.ToString();
}
finally
{
con.Close();
}
return ds;

}

public int ReturnExecuteResult(SqlConnection con, string sql, SqlParameter[] paramters, out string errorMsg)
{
int result = 0;
try
{
SqlCommand cmd = con.CreateCommand();
cmd.CommandText = sql;
cmd.Parameters.Clear();
if (paramters != null || paramters.Length > 0)
{
cmd.Parameters.AddRange(paramters);
}
con.Open();
result = cmd.ExecuteNonQuery();
errorMsg = string.Empty;
cmd.Dispose();
}
catch (Exception ex)
{
errorMsg = ex.ToString();
}
finally
{
con.Close();
}
return result;
}

//TODO 需要增加存储过程操作方法

public void CloseConnection(SqlConnection con)
{
if (con != null && con.State != ConnectionState.Closed)
con.Close();
}

}
}

 

 

//由于时间有限，今天就写到这里