C# 利用MS的 EntLib的Database类编写的DbHelper，可以自动匹配支持Oracle、SQL Server、MySql...

继续回馈ITEYE，绝对原创，好不好各位用了就知道

C# 利用MS的 EntLib的Database类编写的DbHelper，由于MS的EntLib对Oracle、SQL Server和MySql已经封装，所以可以该DbHelper可以适用这三种数据库，根据Web.config中connectionString节点配置数据库连接，会自动根据providerName属性来选择是使用了Oracle数据库还是Sql Server。

需要在Web.config的配置数据库：






各位使用时需要引用微软的EntLib：
using Microsoft.Practices;
using Microsoft.Practices.EnterpriseLibrary.Common.Configuration;
using Microsoft.Practices.EnterpriseLibrary.Data;

1. 实现基本的数据操作： 查询、删除、新增
2. 支持事务
3. 支持存储过程使用参数

不废话，看代码：

#region Last Revised: 2009-02-02
/****************************************************************************************************
* Enterprise Library
* Author: Lin Hai
* Class description: Represent the database operation methods
* Creation date: 2008-07-08
====================================================================================================
* Update history:
* 2008-07-18: Update the Constructor function
* 2009-02-02: Add transaction function
*
****************************************************************************************************/
#endregion
using System;
using System.Data;
using System.Data.SqlClient;
using System.Collections.Generic;
using System.Collections;
using System.IO;
using System.Web;
using Microsoft.Practices;
using Microsoft.Practices.EnterpriseLibrary.Common.Configuration;
using Microsoft.Practices.EnterpriseLibrary.Data;
using System.Data.Common;
using System.Diagnostics;
using System.Text;

namespace WSC.Common
{
///

/// 数据库服务基类，支持SQL Server,Oracle和MySql
///

public class DbHelper : IDisposable
{
private Database db;
private DbConnection conn;
///

///
///

public string LastError = "";

#region Constructor and Destructor
///

/// 数据库服务基类，支持SQL Server,Oracle和MySql
///

public DbHelper()
{
this.LastError = string.Empty;
try
{
db = getDb("");
conn = db.CreateConnection();
conn.Open();
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("DbHelper", "Constructor", ex.StackTrace);
throw new Exception("数据库初始化失败！", ex);
}
}

///

/// 数据库服务基类，支持SQL Server,Oracle和MySql。Represent the system database operation class for local caller.
/// Database connection string
///

public DbHelper(string connectionString)
{
this.LastError = string.Empty;
try
{
db = getDb(connectionString);
conn = db.CreateConnection();
conn.Open();
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("DbHelper", "Constructor", ex.StackTrace);
throw new Exception("数据库初始化失败！", ex);
}
}

private Database getDb(string connectionStringKey)
{

if (String.IsNullOrWhiteSpace(connectionStringKey))
connectionStringKey = Global.ConnectionStringKey;

//return DatabaseFactory.CreateDatabase(connectionString);
return EnterpriseLibraryContainer.Current.GetInstance(connectionStringKey);
}

///

///
///

~DbHelper()
{
this.Dispose();
}

#region IDisposable Members

private bool disposed = false;
///

/// GC
///

public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}

private void Dispose(bool disposing)
{
if (!this.disposed && disposing)
{
try
{
if ((conn != null) && (conn.State != ConnectionState.Closed))
{
conn.Close();
conn.Dispose();
}

if (_transaction != null) _transaction.Dispose();

_transaction = null;
conn = null;

}
catch { }
}
disposed = true;
}
#endregion

#endregion

///

/// Current database
///

public Database GetDatabase
{
get { return db; }
}

#region Execute SQL

///

/// 执行StoreProcedure或Select、Delete、Update等
///

/// 要执行的SQL语句
/// SUCCESS|Error message
public string Execute(string SQL)
{
try
{
if (String.IsNullOrWhiteSpace(SQL))
return "没有可执行的SQL语句";

this.LastError = string.Empty;

using (DbCommand cmd = db.GetSqlStringCommand(SQL))
{
cmd.Connection = conn;

if (_transaction != null && _transaction.Connection.State == ConnectionState.Open)
cmd.Transaction = _transaction;

cmd.CommandType = CommandType.Text;
cmd.CommandTimeout = 600; //10 minutes

this.InjectParameters(cmd);

int ret = cmd.ExecuteNonQuery();
WriteLog("Execute", SQL, "成功， 影响记录数：" + ret.ToString() + "条");
}

return Global.SUCCESS;
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("Execute", SQL, ex.Message + "\\r\\n" + ex.StackTrace);
return "执行失败, -2！ " + ex.Message;
}
}

///

/// 执行多SQL语句，StoreProcedure或Select、Delete、Update等
///

/// 要执行的SQL语句集合
/// true|false
public bool Execute(List SQL)
{
if (SQL == null || SQL.Count == 0)
return false;

StringBuilder sb = new StringBuilder();
SQL.ForEach(x => { sb.AppendLine(x); });

try
{
this.LastError = string.Empty;

using (DbCommand cmd = conn.CreateCommand())
{
if (_transaction != null && _transaction.Connection.State == ConnectionState.Open)
cmd.Transaction = _transaction;

cmd.CommandType = CommandType.Text;
cmd.CommandTimeout = 600; //10 minutes

this.InjectParameters(cmd);

foreach (string sql in SQL)
{
cmd.CommandText = sql;

cmd.ExecuteNonQuery();
}
}

WriteLog("Execute(List[SQL])", sb.ToString(), Global.SUCCESS);
return true;
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("Execute", sb.ToString(), ex.Message + "\\r\\n" + ex.StackTrace);

return false;
}
}

///

/// 执行多SQL语句，StoreProcedure或Select、Delete、Update等，有事务支持。
///

/// 要执行的SQL语句集合
/// true|false
public bool ExecuteWithTransaction(List SQL)
{
if (SQL == null || SQL.Count == 0)
return false;

StringBuilder sb = new StringBuilder();
SQL.ForEach(x => { sb.AppendLine(x); });

DbTransaction transaction = conn.BeginTransaction();

try
{
this.LastError = string.Empty;

using (DbCommand cmd = conn.CreateCommand())
{
cmd.Connection = conn;

if (transaction != null && transaction.Connection.State == ConnectionState.Open)
cmd.Transaction = transaction;

cmd.CommandType = CommandType.Text;
cmd.CommandTimeout = 600; //10 minutes

this.InjectParameters(cmd);

foreach (string sql in SQL)
{
cmd.CommandText = sql;

cmd.ExecuteNonQuery();
}
transaction.Commit();

WriteLog("ExecuteWithTransaction(List[SQL])", sb.ToString(), Global.SUCCESS);
return true;
}
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("Execute", sb.ToString(), ex.Message + "\\r\\n" + ex.StackTrace);

// Attempt to roll back the transaction.
try
{
transaction.Rollback();
}
catch (Exception ex2)
{
WriteErrLog("ExecuteRollback", string.Format("Rollback Exception Type: {0}", ex2.GetType()), string.Format("Message: {0}", ex2.Message));
this.LastError += ex2.Message;
}

return false;
}
}

#endregion

#region Execute StoreProcedure

///

/// 执行StoreProcedure
///

/// 要执行的SQL语句
/// 返回值
/// SUCCESS|Error message
public string ExecuteStoreProcedure(string spName, out List outParams)
{
try
{
this.LastError = string.Empty;

if (String.IsNullOrWhiteSpace(spName))
{
outParams = null;
this.LastError = "没有可执行的存储过程";
return this.LastError;
}

using (DbCommand cmd = db.GetStoredProcCommand(spName))
{
cmd.Connection = conn;

if (_transaction != null && _transaction.Connection.State == ConnectionState.Open)
cmd.Transaction = _transaction;

cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandTimeout = 600; //10 minutes

this.InjectParameters(cmd);

int ret = cmd.ExecuteNonQuery();

outParams = new List();

foreach (DbParameter param in cmd.Parameters)
{
if (param.Direction == ParameterDirection.Output)
{
outParams.Add(new NameValuePair(param.ParameterName, param.Value.ToString()));
}
}

WriteLog("Execute", spName, "成功， 影响记录数：" + ret.ToString() + "条, 返回参数： " + UtilityHelper.ConvertListToString(outParams));
}

return Global.SUCCESS;
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("Execute", spName, ex.Message + "\\r\\n" + ex.StackTrace);
outParams = null;
return "执行失败, -2！ " + "\r\n" + ex.Message;
}
}

///

/// 执行StoreProcedure
///

/// 要执行的SQL语句
/// 执行StoreProcedure获取的数据集
/// 返回值
/// SUCCESS|Error message
public string ExecuteStoreProcedure(string spName, out DataSet ds, out List outParams)
{
try
{
this.LastError = string.Empty;

if (String.IsNullOrWhiteSpace(spName))
{
outParams = null;
ds = null;
this.LastError = "没有可执行的存储过程";
return this.LastError;
}

using (DbCommand cmd = db.GetStoredProcCommand(spName))
{
cmd.Connection = conn;

if (_transaction != null && _transaction.Connection.State == ConnectionState.Open)
cmd.Transaction = _transaction;

cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandTimeout = 600; //10 minutes

this.InjectParameters(cmd);

ds = new DataSet();
db.LoadDataSet(cmd, ds, "OutParams");

outParams = new List();

foreach (DbParameter param in cmd.Parameters)
{
if (param.Direction == ParameterDirection.Output)
{
outParams.Add(new NameValuePair(param.ParameterName, param.Value.ToString()));
}
}

WriteLog("Execute", spName, "成功， 返回参数：" + UtilityHelper.ConvertListToString(outParams));

return Global.SUCCESS;
}
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("Execute", spName, ex.Message + "\\r\\n" + ex.StackTrace);
outParams = null;
ds = null;
return ex.Message;
}
}
#endregion

#region Query
///

/// 执行StoreProcedure或Select，返回查询结果
///

/// 查询的SQL语句
/// 返回一查询结果DataReader
public DbDataReader Reader(string SQL)
{
try
{
this.LastError = string.Empty;

if (String.IsNullOrWhiteSpace(SQL))
{
this.LastError = "没有可执行的SQL语句";
return null;
}

using (DbCommand cmd = db.GetSqlStringCommand(SQL))
{
cmd.Connection = conn;

if (_transaction != null && _transaction.Connection.State == ConnectionState.Open)
cmd.Transaction = _transaction;

this.InjectParameters(cmd);

DbDataReader dr = cmd.ExecuteReader();
//WriteLog("Query", SQL, GlobalDefinition.SUCCESS);
return dr;
}
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("Reader", SQL, ex.Message + "\\r\\n" + ex.StackTrace);
//return null;
throw new Exception("SQL.Reader： " + ex.Message);
}
}


///

/// 执行StoreProcedure或Select，返回查询结果
///

/// 查询的SQL语句
/// 返回一查询结果DataSet
public DataSet Query(string SQL)
{
this.LastError = string.Empty;

if (String.IsNullOrWhiteSpace(SQL))
{
this.LastError = "没有可执行的SQL语句";
return null;
}

try
{
using (DbCommand cmd = db.GetSqlStringCommand(SQL))
{
if (_transaction != null && _transaction.Connection.State == ConnectionState.Open)
cmd.Transaction = _transaction;

this.InjectParameters(cmd);

DataSet ds = new DataSet();
db.LoadDataSet(cmd, ds, "DefaultTableName");
//WriteLog("Query", SQL, GlobalDefinition.SUCCESS);
return ds;
}
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("Query", SQL, ex.Message + "\\r\\n" + ex.StackTrace);
throw new Exception("SQL.Query： " + ex.Message, ex);
}
}

///

/// 执行StoreProcedure或Select，返回查询结果
///

/// 查询的SQL语句
/// 返回一查询结果DataSet
public DataTable QueryTable(string SQL)
{
this.LastError = string.Empty;

if (String.IsNullOrWhiteSpace(SQL))
{
this.LastError = "没有可执行的SQL语句";
return null;
}

try
{
using (DbCommand cmd = db.GetSqlStringCommand(SQL))
{
if (_transaction != null && _transaction.Connection.State == ConnectionState.Open)
cmd.Transaction = _transaction;

this.InjectParameters(cmd);

DataSet ds = new DataSet();

db.LoadDataSet(cmd, ds, "DefaultTableName");
//WriteLog("Query", SQL, GlobalDefinition.SUCCESS);
if (ds != null && ds.Tables.Count > 0)
return ds.Tables[0];
return null;
}
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("Query", SQL, ex.Message + "\\r\\n" + ex.StackTrace);
throw new Exception("SQL.QueryTable: " + ex.Message, ex);
}
}
#endregion

#region Get value

///

/// 根据列序号返回SQL语句第一行,第n列,zero based.
///

/// 查询的SQL语句
/// 列序号
/// 字符串: 第一行,第n列
public string GetValue(string SQL, int ColumnIndex)
{
try
{
this.LastError = string.Empty;

if (String.IsNullOrWhiteSpace(SQL))
{
this.LastError = "没有可执行的SQL语句";
return String.Empty;
}

using (DbDataReader dr = this.Reader(SQL))
{
if (dr.Read())
{
return dr[ColumnIndex].ToString().Trim();
}
return string.Empty;
}
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("GetValue-ColIndex", SQL + "\r\nColIndex=" + ColumnIndex.ToString(), ex.Message + "\\r\\n" + ex.StackTrace);
throw new Exception("SQL.GetValue： " + ex.Message, ex);
}
}

///

/// 根据列名返回SQL语句第一行,第n列
///

/// 查询的SQL语句
/// 列名
/// 字符串: 第一行,第n列
public string GetValue(string SQL, string ColumnName)
{
try
{
if (String.IsNullOrWhiteSpace(SQL))
{
this.LastError = "没有可执行的SQL语句";
return String.Empty;
}

this.LastError = string.Empty;

using (DbDataReader dr = this.Reader(SQL))
{
if (dr.Read())
{
return dr[ColumnName].ToString().Trim();
}
return string.Empty;
}
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("GetValue-ColName", SQL + "\r\nColName=" + ColumnName, ex.Message + "\\r\\n" + ex.StackTrace);
throw new Exception("SQL.GetValue： " + ex.Message, ex);
}
}

///

/// 是否有记录
///

/// 查询的SQL语句
///
public bool HasRows(string SQL)
{
try
{
this.LastError = string.Empty;

if (String.IsNullOrWhiteSpace(SQL))
{
this.LastError = "没有可执行的SQL语句";
return false;
}

using (DbDataReader dr = this.Reader(SQL))
{
if (dr.Read())
{
return true;
}
return false;
}
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("HasRows", SQL, ex.Message + "\\r\\n" + ex.StackTrace);
throw new Exception("SQL.HasRows： " + ex.Message, ex);
}
}

#endregion

#region Transaction

private DbTransaction _transaction;

///

/// 开始事务
///

public bool BeginTransaction()
{

if (db != null && conn != null && conn.State == ConnectionState.Open)
{
try
{
_transaction = conn.BeginTransaction();
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("Transaction", "BeginTransaction", ex.Message + "\\r\\n" + ex.StackTrace);
return false;
}
}
else
{
this.LastError = "You must have a valid connection object before calling BeginTransaction.";
WriteErrLog("Transaction", "BeginTransaction", this.LastError);
return false;
}
return true;
}

///

/// 提交事务
///

public bool CommitTransaction()
{
if (_transaction != null && _transaction.Connection.State == ConnectionState.Open)
{
try
{
_transaction.Commit();
_transaction = null;
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("Transaction", "CommitTransaction", ex.Message + "\\r\\n" + ex.StackTrace);
return false;
}
}
else
{
this.LastError = "You must call BeginTransaction before calling CommitTransaction.";
WriteErrLog("Transaction", "CommitTransaction", this.LastError);
return false;
}
return true;
}

///

/// 回滚事务
///

public bool RollbackTransaction()
{

if (_transaction != null && _transaction.Connection.State == ConnectionState.Open)
{
try
{
_transaction.Rollback();
_transaction = null;
}
catch (Exception ex)
{
this.LastError = ex.Message;
WriteErrLog("Transaction", "RollbackTransaction", ex.Message + "\\r\\n" + ex.StackTrace);
return false;
}
}
else
{
this.LastError = "You must call BeginTransaction before calling RollbackTransaction.";
WriteErrLog("Transaction", "RollbackTransaction", this.LastError);
return false;
}
return true;

}
#endregion

#region Parameters

private List _parameters = new List();
///

/// 参数集
///

public List Parameters
{
get
{
return _parameters;
}
}

#region Add Parameter
///

/// 新增参数
///

/// SQL参数
protected void AddParameter(DbParameter parameter)
{
_parameters.Add(parameter);
}

///

/// 新增参数
///

/// 参数名
/// 数据类型
/// 值
///
public DbParameter AddInParameter(string name, DbType type, object value)
{
return AddInParameter(name, type, value, 500);
}

///

/// 新增参数
///

/// 参数名
/// 数据类型
/// 值
/// 长度
///
public DbParameter AddInParameter(string name, DbType type, object value, int size)
{
if (value == null || String.IsNullOrWhiteSpace(name))
throw new Exception("The parameter name or value is empty.");

DbParameter prm = conn.CreateCommand().CreateParameter();
prm.Direction = ParameterDirection.Input;
prm.ParameterName = name;
prm.DbType = type;
prm.Size = size;
prm.Value = value;

_parameters.Add(prm);

return prm;
}

///

/// 新增参数
///

/// 参数名
/// 数据类型
///
public DbParameter AddOutParameter(string name, DbType type)
{
return AddOutParameter(name, type, 500);
}

///

/// 新增参数
///

/// 参数名
/// 数据类型
/// 长度
///
public DbParameter AddOutParameter(string name, DbType type, int size)
{
if (String.IsNullOrWhiteSpace(name))
throw new Exception("The parameter name is empty.");

DbParameter prm = conn.CreateCommand().CreateParameter();
prm.Direction = ParameterDirection.Output;
prm.ParameterName = name;
prm.DbType = type;
prm.Size = size;

_parameters.Add(prm);

return prm;
}
#endregion

///

/// 清空参数
///

public void ClearParameters()
{
_parameters.Clear();
}

///

/// 为DbCommand对象填充参数
///

/// DbCommand对象
private void InjectParameters(DbCommand command)
{
command.Parameters.Clear();

if (_parameters == null) return;

foreach (DbParameter para in _parameters)
{
if (para != null)
command.Parameters.Add(para);
}

this.ClearParameters(); //注入后清空参数
}
#endregion

#region Write log
///

///
///

///
///
///
private void WriteErrLog(string Function, string SQL, string Message)
{

}

///

///
///

///
///
///
private void WriteLog(string Function, string SQL, string Message)
{

}
#endregion
}
}