找到了2年前我封装的一个SqlHelper.cs,常规使用没有任何问题，仅供参考：
#region
// ===============================================================================
// Project Name :
// Project Description :
// ===============================================================================
// Class Name : SqlHelper
// Class Version : v1.0.0.0
// Class Description : SQL语句辅助类
// CLR : 4.0.30319.18408
// Author : shanzm
// Create Time : 2018-8-14 18:22:59
// Update Time : 2018-8-14 18:22:59
// ===============================================================================
// Copyright © SHANZM-PC 2018 . All rights reserved.
// ===============================================================================
#endregion
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
namespace _16StoreProcedure
{
public class SqlHelper
{
private static readonly string connStr =
ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
/// <summary>
/// 返回查询结果的的表
/// </summary>
/// <param name="sql">SQL语句或存储过程</param>
/// <param name="type">执行类型</param>
/// <param name="param">参数</param>
/// <returns></returns>
public static DataTable GetDataTable(string sql, CommandType type, params SqlParameter[] param)
{
using (SqlConnection conn = new SqlConnection(connStr))
{
using (SqlDataAdapter adapter = new SqlDataAdapter(sql, conn))
{
if (param != null)
{
adapter.SelectCommand.Parameters.AddRange(param);
}
adapter.SelectCommand.CommandType = type;
DataTable da = new DataTable();
adapter.Fill(da);
return da;
}
}
}
/// <summary>
/// 返回影响行数
/// </summary>
/// <param name="sql">SQL语句或存储过程</param>
/// <param name="type">执行类型</param>
/// <param name="param">参数</param>
/// <returns></returns>
public static int ExecuteNonquery(string sql, CommandType type, params SqlParameter[] param)
{
using (SqlConnection conn = new SqlConnection(connStr))
{
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
if (param != null)
{
cmd.Parameters.AddRange(param);
}
cmd.CommandType = type;
conn.Open();
return cmd.ExecuteNonQuery();
}
}
}
/// <summary>
/// 返回查询结果的第一行第一个单元格的数据
/// </summary>
/// <param name="sql">SQL语句或存储过程</param>
/// <param name="type">执行类型</param>
/// <param name="param">参数</param>
/// <returns></returns>
public static object ExecuteScalar(string sql, CommandType type, params SqlParameter[] param)
{
using (SqlConnection conn=new SqlConnection (connStr ))
{
using (SqlCommand cmd=new SqlCommand (sql,conn))
{
if (param !=null )
{
cmd.Parameters.AddRange(param);
}
cmd.CommandType = type ;
conn.Open();
return cmd.ExecuteScalar();
}
}
}
}
}
