很好用的DBHelper类
using System;
using System.Data;
using
System.Data.Common;
using System.Configuration;
namespace
MyDBHelper
{
public class DBHelper
{
private static
string dbProviderName =
ConfigurationManager.AppSettings["DbHelperProvider"];
private static
string dbConnectionString =
ConfigurationManager.AppSettings["DbHelperConnectionString"];
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;
}
//增加参数#region 增加参数
#region
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
//执行#region 执行
#region
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
//执行事务#region 执行事务
#region
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();
}
}
}
}
//那么如何使用它呢?下面我给出一些基本的使用示例,基本能满足你大部分的数据库操作需要了.
//1)直接执行sql语句
// DbHelper db = new DbHelper();
// DbCommand cmd
= db.GetSqlStringCommond("insert t1 (id)values('haha')");
//
db.ExecuteNonQuery(cmd);
//2)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);
//3)返回DataSet
// DbHelper db = new DbHelper();
// DbCommand cmd
= db.GetSqlStringCommond("select * from t1");
// DataSet ds =
db.ExecuteDataSet(cmd);
//4)返回DataTable
// DbHelper db = new DbHelper();
// DbCommand
cmd = db.GetSqlStringCommond("t1_findall");
// DataTable dt =
db.ExecuteDataTable(cmd);
//5)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;//out parameter
// int r = Convert.ToInt32(db.GetParameter(cmd,
"@returnValue").Value);//return value
//6)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;//out parameter
//
int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return
value
//7)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)
//
pubic void DoBusiness()
// {
// using (Trans t = new
Trans())
// {
// try
//
{
// D1(t);
// throw new
Exception();//如果有异常,会回滚滴
// D2(t);
//
t.Commit();
// }
// catch
//
{
// t.RollBack();
// }
// }
//
}
// public void D1(Trans t)
// {
// 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);
// if (t == null) db.ExecuteNonQuery(cmd);
//
else db.ExecuteNonQuery(cmd,t);
// string s = db.GetParameter(cmd, "@outString").Value as
string;//out parameter
// int r = Convert.ToInt32(db.GetParameter(cmd,
"@returnValue").Value);//return value
// }
// public void D2(Trans t)
// {
// DbHelper db
= new DbHelper();
// DbCommand cmd = db.GetSqlStringCommond("insert t1
(id)values('..')");
// if (t == null)
db.ExecuteNonQuery(cmd);
// else db.ExecuteNonQuery(cmd, t);
//
}
//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:
//
<appSettings>
// <add key="DbHelperProvider"
value="System.Data.SqlClient"/>
// <add
key="DbHelperConnectionString" value="Data Source=(local);Initial
Catalog=DbHelperTest;Persist Security Info=True;User
ID=sa;Password=sa"/>
//
</appSettings>其实,DbHelper需要的仅仅是两个字符串,你可以自己修改,作成加密什么的...
//好了,就这样,DbHelper的代码是非常简单和透明的,只是在ado.net上做了一点小包装,改变了一下使用它的程序员的编码方式,去除掉一些比较"物理级"的编程概念,如connection的open和close之类的,使程序员更专注于业务逻辑代码的编写,少死掉点脑细胞,另外,统一了数据操作层的数据操作代码的风格和格式,维护起来很方便的
