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  • 我的SqlHelper类!

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

    namespace Dal
    {
        public class SqlHelper
        {
            /// <summary>
            /// 连接字符串
            /// </summary>
            private static readonly string connStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;

            /// <summary>
            /// 执行Sql语句,返回影响行数(主要用:insert,update,delete)使用查找语句:返回-1
            /// </summary>
            /// <param name="sql"></param>
            /// <param name="cmdtype"></param>
            /// <param name="para"></param>
            /// <returns></returns>
            public static int ExecuteNonQuery(string sql, CommandType cmdtype, params SqlParameter[] para)
            {
                using (SqlConnection conn = new SqlConnection(connStr))
                {
                    using (SqlCommand cmd = new SqlCommand(sql, conn))
                    {
                        cmd.CommandType = cmdtype;
                        if (para != null)
                        {
                            cmd.Parameters.AddRange(para);
                        }
                        if (conn.State != ConnectionState.Open)
                        {
                            conn.Close();
                            conn.Open();
                        }
                        return cmd.ExecuteNonQuery();
                    }
                }
            }
            /// <summary>
            /// 执行Sql语句,返回首行首列的值
            /// </summary>
            /// <param name="sql"></param>
            /// <param name="cmdtype"></param>
            /// <param name="para"></param>
            /// <returns></returns>
            public static object ExecuteScalar(string sql, CommandType cmdtype, params SqlParameter[] para)
            {
                using (SqlConnection conn = new SqlConnection(connStr))
                {
                    using (SqlCommand cmd = new SqlCommand(sql, conn))
                    {
                        cmd.CommandType = cmdtype;
                        if (para != null)
                        {
                            cmd.Parameters.AddRange(para);
                        }
                        if (conn.State != ConnectionState.Open)
                        {
                            conn.Close();
                            conn.Open();
                        }
                        return cmd.ExecuteScalar();
                    }
                }
            }
            /// <summary>
            /// 执行sql语句,返回SqlDataReader
            /// </summary>
            /// <param name="sql"></param>
            /// <param name="cmdtype"></param>
            /// <param name="para"></param>
            /// <returns></returns>
            public static SqlDataReader ExecuteReader(string sql, CommandType cmdtype, params SqlParameter[] para)
            {
                SqlConnection conn = new SqlConnection(connStr);
                using (SqlCommand cmd = new SqlCommand(sql, conn))
                {
                    cmd.CommandType = cmdtype;
                    if (para != null)
                    {
                        cmd.Parameters.AddRange(para);
                    }
                    try
                    {
                        if (conn.State != ConnectionState.Open)
                        {
                            conn.Close();
                            conn.Open();
                        }
                        return cmd.ExecuteReader(CommandBehavior.CloseConnection);
                    }
                    catch
                    {
                        conn.Close();
                        conn.Dispose();
                        throw;
                    }

                }
            }

            public static DataTable ExecuteDataTable(string sql, CommandType cmdtype, params SqlParameter[] para)
            {
                using (SqlConnection conn = new SqlConnection(connStr))
                {
                    using (SqlDataAdapter adt = new SqlDataAdapter(sql, conn))
                    {
                        DataTable dt = new DataTable();
                        adt.SelectCommand.CommandType = cmdtype;
                        if (para != null)
                        {
                            adt.SelectCommand.Parameters.AddRange(para);
                        }
                        if (conn.State != ConnectionState.Open)
                        {
                            conn.Close();
                            conn.Open();
                        }
                        adt.Fill(dt);
                        return dt;

                    }
                }
            }
        }
    }

    附上:WEB.CONFIG配置文件(数据库连接)
        <connectionStrings>
            <add name="Connstr" connectionString="Data Source=.;Initial Catalog=MALL;User Id=name;Password=pwd;" providerName="System.Data.SqlClient"/>
      </connectionStrings>

    持续更新更新~~

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  • 原文地址:https://www.cnblogs.com/jicheng/p/5950803.html
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