zoukankan      html  css  js  c++  java
  • [原]DbHelper-SQL数据库访问助手

    using System;
    using System.Data;
    using System.Data.SqlClient;
    
    namespace Whir.Software.Framework.Ultimate
    {
        /// <summary>
        ///     数据库访问助手
        /// </summary>
        public class DbHelper
        {
            #region 判断连接是否成功
            /// <summary>
            ///     判断连接是否成功!
            /// </summary>
            /// <param name="con"> 链接字符串</param>
            /// <returns>true 表示链接成功,false表示连接失败</returns>
            public static bool IsConnected(string con)
            {
                bool flag;
                var conn = new SqlConnection(con);
                try
                {
                    conn.Open();
                    flag = true;
                }
                catch (Exception)
                {
                    flag = false;
                }
                finally
                {
                    conn.Close();
                }
                return flag;
            }
            #endregion
            #region 执行不带参数sql语句
            /// <summary>
            ///     执行不带参数sql语句
            /// </summary>
            /// <param name="sql">增,删,改sql语句</param>
            /// <param name="con"></param>
            /// <returns>返回所影响的行数</returns>
            public static bool Execute(string sql, string con)
            {
                var cmd = new SqlCommand();
                var connection = new SqlConnection(con);
                try
                {
                    using (connection)
                    {
                        cmd.Connection = connection;
                        cmd.CommandText = sql;
                        connection.Open();
                        cmd.ExecuteNonQuery();
                        return true;
                    }
                }
                catch (Exception)
                {
                    return false;
                }
            }
            #endregion
            #region 执行SQL语句返回DataTable
            /// <summary>
            ///     执行SQL语句返回DataTable
            /// </summary>
            /// <param name="sql"></param>
            /// <param name="con"></param>
            /// <returns></returns>
            public static DataTable ExcuteDataTable(string sql, string con)
            {
                var cmd = new SqlCommand();
                var connection = new SqlConnection(con);
                try
                {
                    using (connection)
                    {
                        cmd.Connection = connection;
                        cmd.CommandText = sql;
                        connection.Open();
                        var da = new SqlDataAdapter(cmd);
                        var ds = new DataSet();
                        da.Fill(ds);
                        return ds.Tables[0];
                    }
                }
                catch (Exception ex)
                {
                    var dt = new DataTable();
                    dt.Columns.Add("异常信息");
                    DataRow row = dt.NewRow();
                    row["异常信息"] = ex.Message;
                    dt.Rows.Add(row);
                    return dt;
                }
            }
            #endregion
            #region 执行SQL语句查询单条记录
            /// <summary>
            ///     执行SQL语句查询单条记录
            /// </summary>
            /// <param name="sql"></param>
            /// <param name="con"></param>
            /// <returns></returns>
            public static object ExecuteScalar(string sql, string con)
            {
                var cmd = new SqlCommand();
                var connection = new SqlConnection(con);
                try
                {
                    using (connection)
                    {
                        cmd.Connection = connection;
                        cmd.CommandText = sql;
                        connection.Open();
                        return cmd.ExecuteScalar();
                    }
                }
                catch (Exception)
                {
                    return string.Empty;
                }
            }
            #endregion
            #region 取得表最大Id
            /// <summary>
            ///     取得表最大Id
            /// </summary>
            /// <param name="tableName"></param>
            /// <param name="fieldName"></param>
            /// <param name="con"></param>
            /// <returns></returns>
            public static int GetMaxId(string tableName, string fieldName, string con)
            {
                string sql = "SELECT NVL(MAX({0}),0)+1 FROM {1}";
                try
                {
                    sql = string.Format(sql, fieldName, tableName);
                    int result;
                    Int32.TryParse(ExecuteScalar(sql, con).ToString(), out result);
                    return result;
                }
                catch (Exception)
                {
                    return -1;
                }
            }
            #endregion
        }
    }

    作者:a497785609 发表于2014-6-1 15:06:22 原文链接
    阅读:8 评论:0 查看评论
  • 相关阅读:
    c++函数模板
    C++左移运算符重载
    and or bool and a or b 原理解释
    Python的垃圾回收机制
    《C++ 101条建议》学习笔记——第一章快速入门
    在应用中嵌入Python:转
    使用C++扩展Python的功能 转自:http://blog.csdn.net/magictong/article/details/8897568#comments
    python扩展实现方法--python与c混和编程 转自:http://www.cnblogs.com/btchenguang/archive/2012/09/04/2670849.html
    python文件头的#-*- coding: utf-8 -*- 的作用
    Pythhon 字典 key in dict 比 dict.has_key (key)效率高 为什么?
  • 原文地址:https://www.cnblogs.com/zhangqs008/p/3763825.html
Copyright © 2011-2022 走看看