ADO.NET的一个帮助类库，只须一个连接，一条SQL语句，轻松实现数据库的查旬，再加一个object 轻松实现数据库的增删改

该类库根据是否需要事务可分为两个部分，分别由三个构造方法决定

命名空间DBAssistant,类DBAssist

方法ExecNoQueryWithTran() 实现带事务的增删改，返回(int)影响的行数

方法 ExecNoQuery()实现不带事务的增删改，返回(int) 影响的行数

方法ExecScalar() 实现返回首行首列的查询，返回(object)

方法ExecSelect() 返回SqlDataReader

方法GetDataSet() 返回DataSet

using System;

using System.Collections.Generic;

using System.Text;

using System.Data;

using System.Data.SqlClient;

using WriteException;

namespace DBAssistant

{

public class DBAssist

{

/// <summary>

/// 重载的构造方法

/// </summary>

public DBAssist() { }

public DBAssist(string strSql,SqlConnection conn)

{

this.StrSql = strSql;

this.Conn = conn;

}

public DBAssist(string strSql,object obj,SqlConnection conn)

{

this.StrSql = strSql;

this.Obj = obj;

this.Conn = conn;

}

public DBAssist(string strSql, object obj, SqlConnection conn,SqlTransaction sqlTran)

{

this.StrSql = strSql;

this.Obj = obj;

this.Conn = conn;

this.sqlTran = sqlTran;

}

/// <summary>

/// sql语句

/// </summary>

string strSql;

public string StrSql

{

get { return strSql; }

set { strSql = value; }

}

/// <summary>

/// 要操作的对象，需要对数据库操作的数据存于其中

/// </summary>

object obj;

public object Obj

{

get { return obj; }

set { obj = value; }

}

/// <summary>

/// 连接

/// </summary>

SqlConnection conn;

public SqlConnection Conn

{

get { return conn; }

set { conn = value; }

}

/// <summary>

/// 事务

/// </summary>

SqlTransaction sqlTran;

public SqlTransaction SqlTran

{

get { return sqlTran; }

set { sqlTran = value; }

}

public object count;

/// <summary>

/// 带事务增删改方法

/// </summary>

/// <returns>int</returns>

public int ExecNoQueryWithTran()

{

int num = 0;

try

{

using (SqlCommand cmd = new SqlCommand(strSql, conn))

{

cmd.Transaction = sqlTran;

num = cmd.ExecuteNonQuery();

//SqlTran.Commit();

}

}

catch (Exception ex)

{

WriException.Write(ex);

//SqlTran.Rollback();

}

return num;

}

/// <summary>

/// 不带事务的增删改方法

/// </summary>

/// <returns>int</returns>

public int ExecNoQuery()

{

int num = 0;

try

{

using (SqlCommand cmd = new SqlCommand(strSql, conn))

{

num = cmd.ExecuteNonQuery();

}

}

catch (Exception ex)

{

WriException.Write(ex);

}

return num;

}

/// <summary>

/// 返回 SqlDataReader 的查询方法

/// </summary>

/// <returns>SqlDataReader</returns>

public SqlDataReader ExecSelect()

{

SqlDataReader dr = null;

try

{

SqlCommand cmd = new SqlCommand(strSql, conn);

dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);

return dr;

}

catch (Exception ex)

{

WriException.Write(ex);

}

return null;

}

/// <summary>

/// 调用ExecuteScalar()方法，返回 object 的查询方法

/// </summary>

/// <returns>Object</returns>

public object ExecScalar()

{

count=null;

try

{

using (SqlCommand cmd = new SqlCommand(strSql, conn))

{

count = cmd.ExecuteScalar();

}

}

catch (Exception ex)

{

WriException.Write(ex);

}

return count;

}

DataSet ds;

/// <summary>

/// 返回DataSet的查询方法

/// </summary>

/// <returns>DataSet</returns>

public DataSet GetDataSet()

{

ds = null;

using (SqlDataAdapter sda = new SqlDataAdapter(strSql, conn))

{

using (ds = new DataSet())

{

sda.Fill(ds);

}

}

return ds;

}

}

}