我的C# - Web - DAL- DBHelper.cs
其中的部分内容是别人的，我修改过了并加入了详细的注释！！！
一、这个DBHelper的大致块儿如下图：
二、下面是具体的源代码：
//命名空间。。。。。
using System;
using System.Data;
using System.Data.Common;
using System.Configuration;
namespace Common
{
public class DBHelper
{
//属性区。。。。。
private static string dbProviderName = ConfigurationManager.AppSettings["DbHelperProvider"];
private static string dbConnectionString = ConfigurationManager.AppSettings["Connstr"];//我的数据库连接字符串，其名称是：Connstr
private DbConnection connection;
//不带参数构造器。（暴露出去方便调用）
public DBHelper()
{
this.connection = CreateConnection(DBHelper.dbConnectionString);//创建连接
}
//带参数构造器。（暴露出去方便调用）
public DBHelper(string connectionString)
{
this.connection = CreateConnection(connectionString);//创建连接
}
/****************************************************< 直接连接 >***********************************************************/
public static DbConnection CreateConnection()
{
DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DBHelper.dbProviderName);
DbConnection dbconn = dbfactory.CreateConnection();
dbconn.ConnectionString = DBHelper.dbConnectionString;
return dbconn;
}
/****************************************************< 带连接字符串的连接 >************************************/
public static DbConnection CreateConnection(string connectionString)
{
DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DBHelper.dbProviderName);
DbConnection dbconn = dbfactory.CreateConnection();
dbconn.ConnectionString = connectionString;
return dbconn;
}
/****************************************************< 获取储存过程 >******************************************/
public DbCommand GetStoredProcCommond(string storedProcedure)
{
DbCommand dbCommand = connection.CreateCommand();
dbCommand.CommandText = storedProcedure;
dbCommand.CommandType = CommandType.StoredProcedure;
return dbCommand;
}
/****************************************************< 获取SQL语句命令 >**************************************/
public DbCommand GetSqlStringCommond(string sqlQuery)
{
DbCommand dbCommand = connection.CreateCommand();
dbCommand.CommandText = sqlQuery;
dbCommand.CommandType = CommandType.Text;
return dbCommand;
}
#region =======================================《 增加参数集合 》=============================
public void AddParameterCollection(DbCommand cmd, DbParameterCollection dbParameterCollection)
{
foreach (DbParameter dbParameter in dbParameterCollection)//foreach（数据类型 标识符 in 表达式）
{
cmd.Parameters.Add(dbParameter);//增加参数
}
}
/****************************************************< 增加输出参数 >*******************************************/
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);
}
/****************************************************< 增加输入参数 >********************************************/
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);
}
/****************************************************< 增加返回输入参数 >****************************************/
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);
}
/****************************************************< 获取参数 >*********************************************/
public DbParameter GetParameter(DbCommand cmd, string parameterName)
{
return cmd.Parameters[parameterName];
}
#endregion
#region========================================《 普通执行 》============================
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;
}
/****************************************************< 执行DataTable >******************************************/
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;
}
/****************************************************< 执行Reader >********************************************/
public DbDataReader ExecuteReader(DbCommand cmd)
{
cmd.Connection.Open();
DbDataReader reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
return reader;
}
/****************************************************< 执行SQL语句，并返回受到这条语句而改变的列 >*******************/
public int ExecuteNonQuery(DbCommand cmd)
{
cmd.Connection.Open();
int ret = cmd.ExecuteNonQuery();
cmd.Connection.Close();
return ret;
}
/*******************************< 执行SQL语句，从数据库中检索单个值返回值是object类型 >**************************/
public object ExecuteScalar(DbCommand cmd)
{
cmd.Connection.Open();
object ret = cmd.ExecuteScalar();
cmd.Connection.Close();
return ret;
}
#endregion
#region=====================================《 带事务的执行 》===============================
/****************************************************< 执行DataSet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;
}
/****************************************************< 执行DataTable事务 >*****************************************/
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;
}
/****************************************************< 执行Reader事务 >********************************************/
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;
}
/****************************************************< ExecuteNonQuery >******************************************/
public int ExecuteNonQuery(DbCommand cmd, Trans t)
{
cmd.Connection.Close();
cmd.Connection = t.DbConnection;
cmd.Transaction = t.DbTrans;
int ret = cmd.ExecuteNonQuery();
return ret;
}
/****************************************************< ExecuteScalar >*********************************************/
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
}
#region=================================================《 事务 》================================
public class Trans : IDisposable //IDisposable 接口:定义一种释放分配的非托管资源的方法
{
private DbConnection conn;//连接
private DbTransaction dbTrans;//事务
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()//commit操作
{
dbTrans.Commit();
this.Colse();
}
public void RollBack()//RollBack操作
{
dbTrans.Rollback();
this.Colse();
}
public void Dispose()
{
this.Colse();
}
public void Colse()
{
if (conn.State == System.Data.ConnectionState.Open)
{
conn.Close();
}
}
}
#endregion
}
三、数据库连接字符串
四、使用DBHelper的Demo
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))
{//该处克添加您需要的代码。。。
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); }
五、我不造程序，我只是程序搬运工！！！
