关于SqlDbHelper的用法! 请高手指教,这个SqlDbHelper的具体用法是怎么用的?还有SqlDbHelper类是在哪个命名空间里?希望讲解详细一些。谢谢!!!! 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 SqlDbHelper其实就是一个封装了连接数据库方法的类,事实上SqlDbHelper类是不存在的,是要自己来写的 给你发一个帮助类吧using System;using System.Collections;using System.Collections.Specialized;using System.Data;using System.Data.SqlClient;using System.Configuration;using System.Data.Common;using System.Collections.Generic; /// <summary> /// 数据访问抽象基础类 /// Copyright (C) 2004-2008 By LiTianPing /// </summary> public abstract class DbHelperSQL { //数据库连接字符串(web.config来配置),可以动态更改connectionString支持多数据库. public static string connectionString =ConfigurationSettings.AppSettings["DSN"]; public DbHelperSQL() { } #region 公用方法 /// <summary> /// 判断是否存在某表的某个字段 /// </summary> /// <param name="tableName">表名称</param> /// <param name="columnName">列名称</param> /// <returns>是否存在</returns> public static bool ColumnExists(string tableName, string columnName) { string sql = "select count(1) from syscolumns where [id]=object_id('" + tableName + "') and [name]='" + columnName + "'"; object res = GetSingle(sql); if (res == null) { return false; } return Convert.ToInt32(res) > 0; } public static int GetMaxID(string FieldName, string TableName) { string strsql = "select max(" + FieldName + ")+1 from " + TableName; object obj = DbHelperSQL.GetSingle(strsql); if (obj == null) { return 1; } else { return int.Parse(obj.ToString()); } } public static bool Exists(string strSql) { object obj = DbHelperSQL.GetSingle(strSql); int cmdresult; if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { cmdresult = 0; } else { cmdresult = int.Parse(obj.ToString()); } if (cmdresult == 0) { return false; } else { return true; } } /// <summary> /// 表是否存在 /// </summary> /// <param name="TableName"></param> /// <returns></returns> public static bool TabExists(string TableName) { string strsql = "select count(*) from sysobjects where id = object_id(N'[" + TableName + "]') and OBJECTPROPERTY(id, N'IsUserTable') = 1"; //string strsql = "SELECT count(*) FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[" + TableName + "]') AND type in (N'U')"; object obj = DbHelperSQL.GetSingle(strsql); int cmdresult; if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { cmdresult = 0; } else { cmdresult = int.Parse(obj.ToString()); } if (cmdresult == 0) { return false; } else { return true; } } 继续 public static bool Exists(string strSql, params SqlParameter[] cmdParms) { object obj = DbHelperSQL.GetSingle(strSql, cmdParms); int cmdresult; if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { cmdresult = 0; } else { cmdresult = int.Parse(obj.ToString()); } if (cmdresult == 0) { return false; } else { return true; } } #endregion #region 执行简单SQL语句 /// <summary> /// 执行SQL语句,返回影响的记录数 /// </summary> /// <param name="SQLString">SQL语句</param> /// <returns>影响的记录数</returns> public static int ExecuteSql(string SQLString) { using (SqlConnection connection = new SqlConnection(connectionString)) { using (SqlCommand cmd = new SqlCommand(SQLString, connection)) { try { connection.Open(); int rows = cmd.ExecuteNonQuery(); return rows; } catch (System.Data.SqlClient.SqlException e) { connection.Close(); throw e; } } } } public static int ExecuteSqlByTime(string SQLString, int Times) { using (SqlConnection connection = new SqlConnection(connectionString)) { using (SqlCommand cmd = new SqlCommand(SQLString, connection)) { try { connection.Open(); cmd.CommandTimeout = Times; int rows = cmd.ExecuteNonQuery(); return rows; } catch (System.Data.SqlClient.SqlException e) { connection.Close(); throw e; } } } } /// <summary> /// 执行多条SQL语句,实现数据库事务。 /// </summary> /// <param name="SQLStringList">多条SQL语句</param> public static int ExecuteSqlTran(List<String> SQLStringList) { using (SqlConnection conn = new SqlConnection(connectionString)) { conn.Open(); SqlCommand cmd = new SqlCommand(); cmd.Connection = conn; SqlTransaction tx = conn.BeginTransaction(); cmd.Transaction = tx; try { int count = 0; for (int n = 0; n < SQLStringList.Count; n++) { string strsql = SQLStringList[n]; if (strsql.Trim().Length > 1) { cmd.CommandText = strsql; count += cmd.ExecuteNonQuery(); } } tx.Commit(); return count; } catch { tx.Rollback(); return 0; } } } 比较两个dataset? 可能是事务 HttpWebRequest可以模拟xmlhttp的post么 请教大家一个程序输出的问题 ★★如何区分同一个对象的不同实例?★ wcf 部署时的错误 搞的吃不好睡不好的,帮帮忙吧 问题:一次性更新多条数据。 关闭句柄窗口 c#开发通讯工具需要兼职工作人员 用c#更改系统时间 回调函数如何跳出问题 NPOI 的查找功能(或是查找与替换),如果有用FpSpread的朋友,我要的就是FpSpread.Search()方法的效果
事实上SqlDbHelper类是不存在的,是要自己来写的
using System;
using System.Collections;
using System.Collections.Specialized;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Data.Common;
using System.Collections.Generic;
/// <summary>
/// 数据访问抽象基础类
/// Copyright (C) 2004-2008 By LiTianPing
/// </summary>
public abstract class DbHelperSQL
{
//数据库连接字符串(web.config来配置),可以动态更改connectionString支持多数据库.
public static string connectionString =ConfigurationSettings.AppSettings["DSN"];
public DbHelperSQL()
{
} #region 公用方法
/// <summary>
/// 判断是否存在某表的某个字段
/// </summary>
/// <param name="tableName">表名称</param>
/// <param name="columnName">列名称</param>
/// <returns>是否存在</returns>
public static bool ColumnExists(string tableName, string columnName)
{
string sql = "select count(1) from syscolumns where [id]=object_id('" + tableName + "') and [name]='" + columnName + "'";
object res = GetSingle(sql);
if (res == null)
{
return false;
}
return Convert.ToInt32(res) > 0;
}
public static int GetMaxID(string FieldName, string TableName)
{
string strsql = "select max(" + FieldName + ")+1 from " + TableName;
object obj = DbHelperSQL.GetSingle(strsql);
if (obj == null)
{
return 1;
}
else
{
return int.Parse(obj.ToString());
}
}
public static bool Exists(string strSql)
{
object obj = DbHelperSQL.GetSingle(strSql);
int cmdresult;
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
cmdresult = 0;
}
else
{
cmdresult = int.Parse(obj.ToString());
}
if (cmdresult == 0)
{
return false;
}
else
{
return true;
}
}
/// <summary>
/// 表是否存在
/// </summary>
/// <param name="TableName"></param>
/// <returns></returns>
public static bool TabExists(string TableName)
{
string strsql = "select count(*) from sysobjects where id = object_id(N'[" + TableName + "]') and OBJECTPROPERTY(id, N'IsUserTable') = 1";
//string strsql = "SELECT count(*) FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[" + TableName + "]') AND type in (N'U')";
object obj = DbHelperSQL.GetSingle(strsql);
int cmdresult;
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
cmdresult = 0;
}
else
{
cmdresult = int.Parse(obj.ToString());
}
if (cmdresult == 0)
{
return false;
}
else
{
return true;
}
}
public static bool Exists(string strSql, params SqlParameter[] cmdParms)
{
object obj = DbHelperSQL.GetSingle(strSql, cmdParms);
int cmdresult;
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
cmdresult = 0;
}
else
{
cmdresult = int.Parse(obj.ToString());
}
if (cmdresult == 0)
{
return false;
}
else
{
return true;
}
}
#endregion #region 执行简单SQL语句 /// <summary>
/// 执行SQL语句,返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
using (SqlCommand cmd = new SqlCommand(SQLString, connection))
{
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.SqlClient.SqlException e)
{
connection.Close();
throw e;
}
}
}
} public static int ExecuteSqlByTime(string SQLString, int Times)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
using (SqlCommand cmd = new SqlCommand(SQLString, connection))
{
try
{
connection.Open();
cmd.CommandTimeout = Times;
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.SqlClient.SqlException e)
{
connection.Close();
throw e;
}
}
}
}
/// <summary>
/// 执行多条SQL语句,实现数据库事务。
/// </summary>
/// <param name="SQLStringList">多条SQL语句</param>
public static int ExecuteSqlTran(List<String> SQLStringList)
{
using (SqlConnection conn = new SqlConnection(connectionString))
{
conn.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
SqlTransaction tx = conn.BeginTransaction();
cmd.Transaction = tx;
try
{
int count = 0;
for (int n = 0; n < SQLStringList.Count; n++)
{
string strsql = SQLStringList[n];
if (strsql.Trim().Length > 1)
{
cmd.CommandText = strsql;
count += cmd.ExecuteNonQuery();
}
}
tx.Commit();
return count;
}
catch
{
tx.Rollback();
return 0;
}
}
}