DbHelper

1、类代码

using System;

using System.Configuration;

using System.Data;

using System.Data.Common;

using System.Data.OleDb;

using System.Data.SqlClient;

namespace Lelog.Data

{

/// <summary>

/// <a href="http://lib.csdn.net/base/14" class='replace_word' title="MySQL知识库" target='_blank' style='color:#df3434; font-weight:bold;'>数据库</a>助手类

/// </summary>

public class DbHelper

{

private static string dbProviderName = ConfigurationSettings.AppSettings["DbProviderName"];

private static string dbConnectionString = ConfigurationManager.AppSettings["TaxInvoiceConn"];


private DbConnection connection;

public DbHelper()

{

this.connection = CreateConnection(DbHelper.dbConnectionString);

}


public DbHelper(string connectionString)

{

this.connection = CreateConnection(connectionString);

}


public static DbConnection CreateConnection()

{

DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);

DbConnection dbconn = dbfactory.CreateConnection();

dbconn.ConnectionString = DbHelper.dbConnectionString;

return dbconn;

}

public static DbConnection CreateConnection(string connectionString)

{

DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);

DbConnection dbconn = dbfactory.CreateConnection();

dbconn.ConnectionString = connectionString;

return dbconn;

}


public DbCommand GetStoredProcCommond(string storedProcedure)

{

DbCommand dbCommand = connection.CreateCommand();

dbCommand.CommandText = storedProcedure;

dbCommand.CommandType = CommandType.StoredProcedure;

return dbCommand;

}

public DbCommand GetSqlStringCommond(string sqlQuery)

{

DbCommand dbCommand = connection.CreateCommand();

dbCommand.CommandText = sqlQuery;

dbCommand.CommandType = CommandType.Text;

return dbCommand;

}

#region 增加参数

public void AddParameterCollection(DbCommand cmd, DbParameterCollection dbParameterCollection)

{

foreach (DbParameter dbParameter in dbParameterCollection)

{

cmd.Parameters.Add(dbParameter);

}

}

public void AddOutParameter(DbCommand cmd, string parameterName, DbType dbType, int size)

{

DbParameter dbParameter = cmd.CreateParameter();

dbParameter.DbType = dbType;

dbParameter.ParameterName = parameterName;

dbParameter.Size = size;

dbParameter.Direction = ParameterDirection.Output;

cmd.Parameters.Add(dbParameter);

}

public void AddInParameter(DbCommand cmd, string parameterName, DbType dbType, object value)

{

DbParameter dbParameter = cmd.CreateParameter();

dbParameter.DbType = dbType;

dbParameter.ParameterName = parameterName;

dbParameter.Value = value;

dbParameter.Direction = ParameterDirection.Input;

cmd.Parameters.Add(dbParameter);

}

public void AddReturnParameter(DbCommand cmd, string parameterName, DbType dbType)

{

DbParameter dbParameter = cmd.CreateParameter();

dbParameter.DbType = dbType;

dbParameter.ParameterName = parameterName;

dbParameter.Direction = ParameterDirection.ReturnValue;

cmd.Parameters.Add(dbParameter);

}

public DbParameter GetParameter(DbCommand cmd, string parameterName)

{

return cmd.Parameters[parameterName];

}


#endregion

#region 执行

public DataSet ExecuteDataSet(DbCommand cmd)

{

DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);

DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();

dbDataAdapter.SelectCommand = cmd;

DataSet ds = new DataSet();

dbDataAdapter.Fill(ds);

return ds;

}


public DataTable ExecuteDataTable(DbCommand cmd)

{

DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);

DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();

dbDataAdapter.SelectCommand = cmd;

DataTable dataTable = new DataTable();

dbDataAdapter.Fill(dataTable);

return dataTable;

}


public DbDataReader ExecuteReader(DbCommand cmd)

{

cmd.Connection.Open();

DbDataReader reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);

return reader;

}

public int ExecuteNonQuery(DbCommand cmd)

{

cmd.Connection.Open();

int ret = cmd.ExecuteNonQuery();

cmd.Connection.Close();

return ret;

}


public object ExecuteScalar(DbCommand cmd)

{

cmd.Connection.Open();

object ret = cmd.ExecuteScalar();

cmd.Connection.Close();

return ret;

}

#endregion

#region 执行事务

public DataSet ExecuteDataSet(DbCommand cmd, Trans t)

{

cmd.Connection = t.DbConnection;

cmd.Transaction = t.DbTrans;

DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);

DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();

dbDataAdapter.SelectCommand = cmd;

DataSet ds = new DataSet();

dbDataAdapter.Fill(ds);

return ds;

}


public DataTable ExecuteDataTable(DbCommand cmd, Trans t)

{

cmd.Connection = t.DbConnection;

cmd.Transaction = t.DbTrans;

DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);

DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();

dbDataAdapter.SelectCommand = cmd;

DataTable dataTable = new DataTable();

dbDataAdapter.Fill(dataTable);

return dataTable;

}


public DbDataReader ExecuteReader(DbCommand cmd, Trans t)

{

cmd.Connection.Close();

cmd.Connection = t.DbConnection;

cmd.Transaction = t.DbTrans;

DbDataReader reader = cmd.ExecuteReader();

DataTable dt = new DataTable();

return reader;

}

public int ExecuteNonQuery(DbCommand cmd, Trans t)

{

cmd.Connection.Close();

cmd.Connection = t.DbConnection;

cmd.Transaction = t.DbTrans;

int ret = cmd.ExecuteNonQuery();

return ret;

}


public object ExecuteScalar(DbCommand cmd, Trans t)

{

cmd.Connection.Close();

cmd.Connection = t.DbConnection;

cmd.Transaction = t.DbTrans;

object ret = cmd.ExecuteScalar();

return ret;

}

#endregion

}


public class Trans : IDisposable

{

private DbConnection conn;

private DbTransaction dbTrans;

public DbConnection DbConnection

{

get { return this.conn; }

}

public DbTransaction DbTrans

{

get { return this.dbTrans; }

}


public Trans()

{

conn = DbHelper.CreateConnection();

conn.Open();

dbTrans = conn.BeginTransaction();

}

public Trans(string connectionString)

{

conn = DbHelper.CreateConnection(connectionString);

conn.Open();

dbTrans = conn.BeginTransaction();

}

public void Commit()

{

dbTrans.Commit();

this.Colse();

}


public void RollBack()

{

dbTrans.Rollback();

this.Colse();

}


public void Dispose()

{

this.Colse();

}


public void Colse()

{

if (conn.State == System.Data.ConnectionState.Open)

{

conn.Close();

}

}


}

}

2、直接执行sql语句

DbHelper db = new DbHelper();

DbCommand cmd = db.GetSqlStringCommond("insert t1 (id)values(‘?haha‘?)");

db.ExecuteNonQuery(cmd);

3、执行存储过程

DbHelper db = new DbHelper();

DbCommand cmd = db.GetStoredProcCommond("t1_insert");

db.AddInParameter(cmd, "@id", DbType.String, "heihei");

db.ExecuteNonQuery(cmd);

4、返回DataSet

DbHelper db = new DbHelper();

DbCommand cmd = db.GetSqlStringCommond("select * from t1");

DataSet ds = db.ExecuteDataSet(cmd);

5、返回DataTable

DbHelper db = new DbHelper();

DbCommand cmd = db.GetSqlStringCommond("t1_findall");

DataTable dt = db.ExecuteDataTable(cmd);

6、输入参数/输出参数/返回值的使用(比较重要哦)

DbHelper db = new DbHelper();

DbCommand cmd = db.GetStoredProcCommond("t2_insert");

db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);

db.AddOutParameter(cmd, "@outString", DbType.String, 20);

db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);


db.ExecuteNonQuery(cmd);


string s = db.GetParameter(cmd, "@outString").Value as string;

int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);

7、DataReader使用

DbHelper db = new DbHelper();

DbCommand cmd = db.GetStoredProcCommond("t2_insert");

db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);

db.AddOutParameter(cmd, "@outString", DbType.String, 20);

db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);


using (DbDataReader reader = db.ExecuteReader(cmd))

{

dt.Load(reader);

}

string s = db.GetParameter(cmd, "@outString").Value as string;

int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);

8、事务的使用.(项目中需要将基本的数据库操作组合成一个完整的业务流时,代码级的事务是必不可少的哦)

以上我们好像没有指定数据库连接字符串,大家如果看下DbHelper的代码,就知道要使用它必须在config中配置两个参数,如下:

pubic void DoBusiness()

{

using (Trans t = new Trans())

{

try

{

D1(t);

throw new Exception();

D2(t);

t.Commit();

}

catch

{

t.RollBack();

}

}

}

public void D1(Trans t)

{

DbHelper db = new DbHelper();

DbCommand cmd = db.GetStoredProcCommond("table_insert");

db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);

db.AddOutParameter(cmd, "@outString", DbType.String, 20);

db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);


if (t == null) db.ExecuteNonQuery(cmd);

else db.ExecuteNonQuery(cmd,t);


string s = db.GetParameter(cmd, "@outString").Value as string;

int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);

}

public void D2(Trans t)

{

DbHelper db = new DbHelper();

DbCommand cmd = db.GetSqlStringCommond("insert table (id)values(@id)");

if (t == null) db.ExecuteNonQuery(cmd);

else db.ExecuteNonQuery(cmd, t);

}