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  • sqlHelper

    using System;
    using System.Text;
    using System.Data;
    using System.Data.Sql;
    using System.Data.SqlClient;
    using System.Collections;
    namespace GJ
    {
        using System.Configuration;
        using System.Data;//DatSet..Table SqlDataAdapter
        using System.Data.SqlClient;//SqlConnection Command DataReader
        
            public class SqlHelper
            {
                //连接字符串
                //1、添加引用 2、导入命名空间 为了使用ConfigurationManager
                private static string conStr = Properties.Resources.DBConnection;

                //增删改查
                //查找数据  ExecuteScalar()返回首行首列   ExecuteReader()  DataTable


                /// <summary>
                /// 返回DataTable
                /// </summary>
                /// <param name="sql">所用的sql语句</param>
                /// <param name="param">可变,可以传参也可以不传参数</param>
                /// <returns></returns>
                public static DataTable ExecuteDataTable(string sql, params SqlParameter[] param)
                {
                    DataTable dt = new DataTable();
                    using (SqlConnection con = new SqlConnection(conStr))
                    {
                        using (SqlDataAdapter adapter = new SqlDataAdapter(sql, con))
                        {
                            //添加参数
                            adapter.SelectCommand.Parameters.AddRange(param);
                            //1.打开链接,如果连接没有打开,则它给你打开;如果打开,就算了
                            //2.去执行sql语句,读取数据库
                            //3.sqlDataReader,把读取到的数据填充到内存表中
                            adapter.Fill(dt);
                        }
                    }
                    return dt;
                }
                /// <summary>
                /// 向数据库提交修改的数据
                /// </summary>
                /// <param name="dt"></param>
                /// <returns></returns>
                public static int ExecuteUpdate(string sql,DataTable dt)
                {
                    int lines=0;
                    using (SqlConnection con = new SqlConnection(conStr))
                    {
                        using (SqlDataAdapter adapter = new SqlDataAdapter(sql,con))
                        {
                            using (SqlCommandBuilder cb = new SqlCommandBuilder(adapter))
                            {
                                lines=adapter.Update(dt);
                            }
                            
                        }
                    }
                    return lines;
                }

                /// <summary>
                /// 执行查询,返回首行首列
                /// </summary>
                /// <param name="sql"></param>
                /// <param name="param"></param>
                /// <returns></returns>
                public static object ExecuteScalar(string sql, params SqlParameter[] param)
                {
                    object o = null;
                    using (SqlConnection con = new SqlConnection(conStr))
                    {
                        using (SqlCommand cmd = new SqlCommand(sql, con))
                        {
                            cmd.Parameters.AddRange(param);
                            con.Open();

                            o = cmd.ExecuteScalar();
                        }
                    }
                    return o;
                }


                /// <summary>
                /// 执行查询,返回SqlDataReader对象
                /// </summary>
                /// <param name="sql"></param>
                /// <param name="param"></param>
                /// <returns></returns>
                public static SqlDataReader ExecuteReader(string sql, params SqlParameter[] param)
                {
                    SqlDataReader reader = null;
                    using (SqlConnection con = new SqlConnection(conStr))
                    {
                        using (SqlCommand cmd = new SqlCommand(sql, con))
                        {
                            cmd.Parameters.AddRange(param);
                            con.Open();

                            reader = cmd.ExecuteReader();
                        }
                    }
                    return reader;
                }

                /// <summary>
                /// 执行增删改,返回受影响的行数
                /// </summary>
                /// <param name="sql"></param>
                /// <param name="param"></param>
                /// <returns></returns>
                public static int ExecuteNonQuery(string sql, params SqlParameter[] param)
                {
                    int n = -1;
                    using (SqlConnection con = new SqlConnection(conStr))
                    {
                        using (SqlCommand cmd = new SqlCommand(sql, con))
                        {
                            cmd.Parameters.AddRange(param);
                            con.Open();
                            n = cmd.ExecuteNonQuery();
                        }
                    }
                    return n;
                }

            }
        
    }

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  • 原文地址:https://www.cnblogs.com/clarklxr/p/9667443.html
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