关于数据库操作的重复使用归类

web.config 文件

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<configuration>
<!--连接字符串-->
<connectionStrings>
<add name="sql2005" connectionString="Data Source=.;Initial catalog=MySchool;uid=sa;pwd=221221"/>
</connectionStrings>

<system.web>
<compilation debug="true" targetFramework="4.0"/>
</system.web>
</configuration>

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类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data;
using System.Data.SqlClient;
/// <summary>
///DBHelper 的摘要说明
/// </summary>
public static class DBHelper
{

//  private readonly static String connStr = "Data Source=.\\sqlexpress;Initial catalog=ShoppingCart;User ID=sa;Password=221221";
private static readonly String conStr=System.Configuration.ConfigurationManager.ConnectionStrings["sql2005"].ConnectionString;

public static SqlConnection GetConnection
{
get{return new SqlConnection(conStr);}
}

//增、删、改
public static int ExcuteCommand(String safeSql)
{
int result = 0;
using (SqlConnection conn=GetConnection)
{
conn.Open();
SqlCommand cmd = new SqlCommand(safeSql, conn);
result=cmd.ExecuteNonQuery();
}
return result;
}
//重载（增、删、改）带参数
//public static int ExcuteCommand(String safeSql, params SqlParameter[] parm)//带params可变数组
public static int ExcuteCommand(String safeSql,  SqlParameter[] parm)//带params可变数组
{
int result = 0;
using (SqlConnection conn=GetConnection)
{
conn.Open();
SqlCommand cmd = new SqlCommand(safeSql, conn);
cmd.Parameters.AddRange(parm);
result = cmd.ExecuteNonQuery();
}
return result;
}

//返回第一行第一列
public static Object GetScalar( string safeSql)
{
Object obj = null;
using (SqlConnection conn=GetConnection)
{

conn.Open();
SqlCommand cmd = new SqlCommand(safeSql, conn);
obj = cmd.ExecuteScalar();
}
return obj;
}

//返回第一行第一列，带参数
public static Object GetScalar(string safeSql,SqlParameter [] parm)
{
Object obj = null;
using (SqlConnection conn = GetConnection)
{
conn.Open();
SqlCommand cmd = new SqlCommand(safeSql, conn);
cmd.Parameters.AddRange(parm);
obj = cmd.ExecuteScalar();
}
return obj;
}
//返回结果集
public static SqlDataReader GetDataReader(string safeSql)
{
SqlConnection conn = GetConnection;
conn.Open();
SqlCommand cmd = new SqlCommand(safeSql,conn);
return cmd.ExecuteReader(CommandBehavior.CloseConnection);//关闭Reader
}

//带参数,返回结果集
public static SqlDataReader GetDataReader(string safeSql,SqlParameter[] parm)
{
SqlConnection conn = GetConnection;
conn.Open();
SqlCommand cmd = new SqlCommand(safeSql, conn);
cmd.Parameters.AddRange(parm);
return cmd.ExecuteReader(CommandBehavior.CloseConnection);
}

//查询表
public static DataTable GetDataTable(string safesql)
{
DataTable dt = new DataTable();
SqlDataAdapter sda = new SqlDataAdapter(safesql, GetConnection);
sda.Fill(dt);
return dt;

}
//查询表带参数
public static DataTable GetDataTable(string safesql,SqlParameter [] parm)
{
DataTable dt = new DataTable();
SqlDataAdapter sda = new SqlDataAdapter(safesql, GetConnection);
sda.SelectCommand.Parameters.AddRange(parm);
sda.Fill(dt);
return dt;
}

}

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后台操作！

//不带参数
DBHelper.ExcuteCommand("insert into Admin Values('A001','A001')");
//带参数
string sql = "insert into Admin values（@LoginID，@LoginPwd）";
SqlParameter[] par =
{
new SqlParameter("@LoginID","A002"),
new SqlParameter("@LoginPwd","A002"),
};

DBHelper.ExcuteCommand(sql, par);

//可变数组 数组过多不适用
//DBHelper.ExcuteCommand(sql,new SqlParameter("@LoginID", "A002"),new SqlParameter("@LoginPwd", "A002"));

例子

string sql = "select * from Student where StudentName like @StudentName";
SqlParameter[] par =
{
new SqlParameter("@StudentName","%" + txtStuName.Text + "%"),

};

gvStudent.DataSource = DBHelper.GetDataTable(sql,par);
gvStudent.DataBind();