C#的DbHelper ACCESS数据库
DbHelper ACCESS数据库
using System;
using System.Text;
using System.Collections;
using System.Collections.Specialized;
using System.Data;
using System.Data.OleDb;
using System.Configuration;
namespace NMJU.Web.DBUtility
{ ///
/// 数据访问抽象基础类(ACCESS)
/// Copyright (C) 2006-2007 https://www.wendangku.net/doc/aa14480540.html,
/// All rights reserved
///
public abstract class DbHelperACE
{
//数据库连接字符串(web.config来配置)
//public static string connectionString = ConfigurationManager.AppSettings["ConnectionString"];
// public static string connectionString = System.Web.HttpContext.Current.Server.MapPath(ConfigurationManager.AppSettings["AccessConnectionString"]);
public static string connectionString = ConfigurationManager.AppSettings["AccessConnectionString"];
//public static string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=namedb.mdb";
public DbHelperACE()
{
}
#region 公用方法
///
/// 获取最大id
///
///
///
///
public static int GetMaxID(string FieldName, string TableName)
{
string strsql = "select max(" + FieldName + ")+1 from " + TableName;
object obj = DbHelperACE.GetSingle(strsql);
if (obj == null)
{
return 1;
}
else
{
return int.Parse(obj.ToString());
}
}
///
/// 查询记录是否存在 1
///
///
///
public static bool Exists(string strSql)
{
object obj = DbHelperACE.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;
}
}
///
/// 查询记录是否存在 2
///
///
///
///
public static bool Exists(string strSql, params OleDbParameter[] cmdParms)
{
object obj = DbHelperACE.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
///
/// 执行SQL语句，返回影响的记录数
///
/// SQL语句
///
public static int ExecuteSql(string SQLString)
{
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
using (OleDbCommand cmd = new OleDbCommand(SQLString, connection))
{
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.OleDb.OleDbException E)
{
connection.Close();
throw new Exception(E.Message);
}
}
}
}
///
/// 执行SQL语句，可以设置命令的执行等待时间
///
///
///
///
public static int ExecuteSqlByTime(string SQLString, int Times)
{
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
using (OleDbCommand cmd = new OleDbCommand(SQLString, connection))
{
try
{
connection.Open();
https://www.wendangku.net/doc/aa14480540.html,mandTimeout = Times;
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.OleDb.OleDbException E)
{
connection.Close();
throw new Exception(E.Message);
}
}
}
}
///
/// 执行多条SQL语句，实现数据库事务。
///
/// 多条SQL语句
public static void ExecuteSqlTran(ArrayList SQLStringList)
{
using (OleDbConnection conn = new OleDbConnection(connectionString))
{
conn.Open();
OleDbCommand cmd = new OleDbCommand();
cmd.Connection = conn;
OleDbTransaction tx = conn.Begi
nTransaction();
cmd.Transaction = tx;
try
{
for (int n = 0; n < SQLStringList.Count; n++)
{
string strsql = SQLStringList[n].ToString();
if (strsql.Trim().Length > 1)
{
https://www.wendangku.net/doc/aa14480540.html,mandText = strsql;
cmd.ExecuteNonQuery();
}
}
https://www.wendangku.net/doc/aa14480540.html,mit();
}
catch (System.Data.OleDb.OleDbException E)
{
tx.Rollback();
throw new Exception(E.Message);
}
}
}
///
/// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
///
/// SQL语句
/// 图像字节,数据库的字段类型为image的情况
///
public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
{
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
OleDbCommand cmd = new OleDbCommand(strSQL, connection);
System.Data.OleDb.OleDbParameter myParameter = new System.Data.OleDb.OleDbParameter("@fs", SqlDbType.Image);
myParameter.Value = fs;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.OleDb.OleDbException E)
{
throw new Exception(E.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
///
/// 执行一条计算查询结果语句，返回查询结果（object）。
///
/// 计算查询结果语句
///
public static object GetSingle(string SQLString)
{
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
using (OleDbCommand cmd = new OleDbCommand(SQLString, connection))
{
try
{
connection.Open();
object obj = cmd.ExecuteScalar();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (System.Data.OleDb.OleDbException e)
{
connection.Close();
throw new Exception(e.Message);
}
}
}
}
///
/// 执行查询语句，返回SqlDataReader(使用该方法切记要手工关闭SqlDataReader和连接)
///
/// 查询语句
///
public static OleDbDataReader ExecuteReader(string strSQL)
{
OleDbConnection connection = new OleDbConnection(connectionString);
OleDbCommand cmd = new OleDbCommand(strSQL, connection);
try
{
connection.Open();
OleDbDataReader myReader = cmd.ExecuteReader();
return myReader;
}
catch (System.Data.OleDb.OleDbException e)
{
throw new Exception(e.Message);
}
//finally //不能在此关闭，否则，返回的对象将无法使用
//{
// cmd.Dispose();
// connection.Close();
//}
}
///
/// 执行查询语句，返回DataSet
///
/// 查询语句
///
public static DataSet Query(string SQLString)
{
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
DataSet ds = new DataSet();
try
{
connection.Open();
OleDbDataAdapter command = new OleDbDataAdapter(SQLString, connection);
command.Fill(ds, "ds");//参数1 数据集 参数2 数据集填充的内存表名
}
catch (System.Data.OleDb.OleDbException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
}
///
/// 执行查询语句，返回DataSet,设置命令的执行等待时间
///
///
///
///
public static DataSet Query(string SQLString, int Times)
{
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
DataSet ds = new DataSet();
try
{
connection.Open();
OleDbDataAdapter command = new OleDbDataAdapter(SQLString, connection);
https://www.wendangku.net/doc/aa14480540.html,mandTimeout = Times;
command.Fill(ds, "ds");
}
catch (System.Data.OleDb.OleDbException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
}
#endregion
#region 执行带参数的SQL语句
///
/// 执行SQL语句，返回影响的记录数
///
/// SQL语句
///
public static int ExecuteSql(string SQLString, params OleDbParameter[] cmdParms)
{
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
using (OleDbCommand cmd = new OleDbCommand())
{
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
int rows = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return rows;
}
catch (System.Data.OleDb.OleDbException E)
{
throw new Exception(E.Message);
}
}
}
}
///
/// 执行多条SQL语句，实现数据库事务。
///
/// SQL语句的哈希表（key为sql语句，value是该语句的OleDbParameter[]）
public static void ExecuteSqlTran(Hashtable SQLStringList)
{
using (OleDbConnection conn = new OleDbConnection(connectionString))
{
conn.Open();
using (OleDbTransaction trans = conn.BeginTransaction())
{
OleDbCommand cmd = new OleDbCommand();
try
{
//循环
foreach (DictionaryEntry myDE in SQLStringList)
{
string cmdText = myDE.Key.ToString();
OleDbParameter[] cmdParms = (OleDbParameter[])myDE.Value;
PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
https://www.wendangku.net/doc/aa14480540.html,mit();
}
}
catch
{
trans.Rollback();
throw;
}
}
}
}
///
/// 执行一条计算查询结果语句，返回查询结果（object）。
///
/// 计算查询结果语句
///
public static object GetSingle(string SQLString, params OleDbParameter[] cmdParms)
{
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
using (OleDbCommand cmd = new OleDbCommand())
{
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
object obj = cmd.ExecuteScalar();
cmd.Parameters.Clear();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (System.Data.OleDb.OleDbException e)
{
throw new Exception(e.Message);
}
}
}
}
///
/// 执行查询语句，返回SqlDataReader (使用该方法切记要手工关闭SqlDataReader和连接)
///
/// 查询语句
///
public static OleDbDataReader ExecuteReader(string SQLString, params OleDbParameter[] cmdParms)
{
OleDbConnection connection = new OleDbConnection(connectionString);
OleDbCommand cmd = new OleDbCommand();
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
OleDbDataReader myReader = cmd.ExecuteReader();
cmd.Parameters.Clear();
return myReader;
}
catch (System.Data.OleDb.OleDbException e)
{
throw new Exception(e.Message);
}
//finally //不能在此关闭，否则，返回的对象将无法使用
//{
// cmd.Dispose();
// connection.Close();
//}
}
///
/// 执行查询语句，返回DataSet
///
/// 查询语句
///
public static DataSet Query(string SQLString, params OleDbParameter[] cmdParms)
{
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
OleDbCommand cmd = new OleDbCommand();
PrepareCommand(cmd, c
onnection, null, SQLString, cmdParms);
using (OleDbDataAdapter da = new OleDbDataAdapter(cmd))
{
DataSet ds = new DataSet();
try
{
da.Fill(ds, "ds");
cmd.Parameters.Clear();
}
catch (System.Data.OleDb.OleDbException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
}
}
//抽取的执行方法
private static void PrepareCommand(OleDbCommand cmd, OleDbConnection conn, OleDbTransaction trans, string cmdText, OleDbParameter[] cmdParms)
{
if (conn.State != ConnectionState.Open)
conn.Open();
cmd.Connection = conn;
https://www.wendangku.net/doc/aa14480540.html,mandText = cmdText;
if (trans != null)
cmd.Transaction = trans;
https://www.wendangku.net/doc/aa14480540.html,mandType = CommandType.Text;//cmdType;
if (cmdParms != null)
{
foreach (OleDbParameter parameter in cmdParms)
{
if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
(parameter.Value == null))
{
parameter.Value = DBNull.Value;
}
cmd.Parameters.Add(parameter);
}
}
}
#endregion
#region 获取根据指定字段排序并分页查询。
/**/
///
/// 分页查询数据记录总数获取
///
/// ----要显示的表或多个表的连接
/// ----主表的主键
/// ----查询条件,不需where
/// ----是否添加查询字段的 DISTINCT 默认0不添加/1添加
///
public static string getPageListCounts(string _ID, string _tbName, string _strCondition, int _Dist)
{
//---存放取得查询结果总数的查询语句
//---对含有DISTINCT的查询进行SQL构造
//---对含有DISTINCT的总数查询进行SQL构造
string strTmp = "", SqlSelect = "", SqlCounts = "";
if (_Dist == 0)
{
SqlSelect = "Select ";
SqlCounts = "COUNT(*)";
}
else
{
SqlSelect = "Select DISTINCT ";
SqlCounts = "COUNT(DISTINCT " + _ID + ")";
}
if (_strCondition == string.Empty)
{
strTm
p = SqlSelect + " " + SqlCounts + " FROM " + _tbName;
}
else
{
strTmp = SqlSelect + " " + SqlCounts + " FROM " + " Where (1=1) " + _strCondition;
}
return strTmp;
}
///
/// 智能返回SQL语句
///
/// 主键（不能为空）
/// 提取字段（不能为空）
/// 表（理论上允许多表）
/// 条件（可以空）
/// 排序，格式：字段名+""+ASC（可以空）
/// 分页数（不能为空）
/// 当前页，起始为：1（不能为空）
///
public static string getPageListSql(string primaryKey, string queryFields, string tableName, string condition, string orderBy, int pageSize, int pageIndex)
{
string strTmp = ""; //---strTmp用于返回的SQL语句
string SqlSelect = "", SqlPrimaryKeySelect = "", strOrderBy = "", strWhere = " where 1=1 ", strTop = "";
//0：分页数量
//1:提取字段
//2:表
//3:条件
//4:主键不存在的记录
//5:排序
SqlSelect = " select top {0} {1} from {2} {3} {4} {5}";
//0:主键
//1:TOP数量,为分页数*(排序号-1)
//2:表
//3:条件
//4:排序
SqlPrimaryKeySelect = " and {0} not in (select {1} {0} from {2} {3} {4}) ";
if (orderBy != "")
strOrderBy = " order by " + orderBy;
if (condition != "")
strWhere += " and " + condition;
int pageindexsize = (pageIndex - 1) * pageSize;
if (pageindexsize > 0)
{
strTop = " top " + pageindexsize.ToString();
SqlPrimaryKeySelect = String.Format(SqlPrimaryKeySelect, primaryKey, strTop, tableName, strWhere, strOrderBy);
strTmp = String.Format(SqlSelect, pageSize.ToString(), queryFields, tableName, strWhere, SqlPrimaryKeySelect, strOrderBy);
}
else
{
strTmp = String.Format(SqlSelect, pageSize.ToString(), queryFields, tableName, strWhere, "", strOrderBy);
}
return strTmp;
}
///
/// 获取根据指定字段排序并分页查询。DataSet
///
/// 每页要显示的记录的数目
/// 要显示的页的索引
/// <
param name="tableName">要查询的数据表
/// 要查询的字段,如果是全部字段请填写：*
/// 主键字段，类似排序用到
/// 是否为升序排列：0为升序，1为降序
/// 查询的筛选条件
///
public static DataSet GetPagingList(string primaryKey, string queryFields, string tableName, string condition, string orderBy, int pageSize, int pageIndex)
{
string sql = getPageListSql(primaryKey, queryFields, tableName, condition, orderBy, pageSize, pageIndex);
return Query(sql);
}
//获得拼接后的sql语句
public static string GetPagingListSQL(string primaryKey, string queryFields, string tableName, string condition, string orderBy, int pageSize, int pageIndex)
{
string sql = getPageListSql(primaryKey, queryFields, tableName, condition, orderBy, pageSize, pageIndex);
return sql;
}
//获得执行影响行数
public static int GetRecordCount(string _ID, string _tbName, string _strCondition, int _Dist)
{
string sql = getPageListCounts(_ID, _tbName, _strCondition, _Dist);
object obj = DbHelperACE.GetSingle(sql);
if (obj == null)
{
return 1;
}
else
{
return int.Parse(obj.ToString());
}
}
#endregion
}
}
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