个人任务管理系统-DAL层

数据访问类：

[code]using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using Model;

namespace DAL
{
public class DALTaskS
{
/// <summary>
/// 初始加载查询&条件查询
/// </summary>
/// <param name="ProjectID">所属项目ID</param>
/// <param name="Content">任务内容</param>
/// <param name="TaskState">任务状态（未完成 1，已完成 2）</param>
/// <returns></returns>
public static DataTable SelectAllinfo(string ProjectID="0", string Content="", string TaskState="3")
{
string sql = "select TaskID,ProjectID,TaskPriority,Content,AddTime,TaskState,FinishedTime from Task  where 1=1 ";
if (ProjectID != "0")
{
sql += string.Format(" and ProjectID ={0}", int.Parse(ProjectID));
}
if (Content != "")
{
sql += string.Format(" and Content like '%{0}%'", Content);
}
if (TaskState != "3")
{
sql += string.Format(" and TaskState ={0}", int.Parse(TaskState));
}

//返回查询结果。
return SQLhelper.Query(sql);
}

/// <summary>
/// 下拉列表查询
/// </summary>
/// <returns></returns>
public static DataTable DrapDownListSelect()
{
string sql = "select * from Project";
return SQLhelper.Query(sql);
}

/// <summary>
/// 删除语句
/// </summary>
/// <param name="TaskID">项目ID</param>
/// <returns>受影响行数（删除行数）</returns>
public static int DeleteProInfo(string TaskID)
{
string sql = "delete from Task where TaskID ="+int.Parse(TaskID);
return SQLhelper.NonQuery(sql);
}

/// <summary>
/// 完成项目
/// </summary>
/// <param name="TaskID"></param>
/// <returns></returns>
public static int UpdateProInfo(string TaskID)
{
string sql = string.Format("update Task set TaskState = 2,FinishedTime={0} where TaskID ={1} ", DateTime.Today.ToShortDateString(), int.Parse(TaskID));
return SQLhelper.NonQuery(sql);
}

/// <summary>
/// 添加新项目
/// </summary>
/// <param name="TaskPriority">项目优先级</param>
/// <param name="Content">项目内容</param>
/// <param name="ProjectID">项目所属编号</param>
/// <returns></returns>
public static int InsertProInfo(string TaskPriority, string Content, string ProjectID)
{
string sql = string.Format("insert into Task values ({0},'{1}',GETDATE(),1,null,{2})",int.Parse(TaskPriority),Content,int.Parse(ProjectID));
return SQLhelper.NonQuery(sql);
}
}
}

帮助类：

[code]using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace DAL
{
//SQL语句帮助
public class SQLhelper
{
//连接字符串
private static string strCon = ConfigurationManager.ConnectionStrings["TestConnectionString1"].ConnectionString;

/// <summary>
/// 查询帮助
/// </summary>
/// <param name="sql">类型为字符串类型的sql语句</param>
/// <returns></returns>
public static DataTable Query(string sql)
{
//空数据表
DataTable tab = new DataTable();

//适配器   第一个参数是SQL语句，第二个参数是连接字符串
SqlDataAdapter sda = new SqlDataAdapter(sql, strCon);

//填充空表
sda.Fill(tab);

//返回有数据的表
return tab;

}

public static int NonQuery(string sql)
{
//返回行数变量
int num = 0;

//连接字符串
SqlConnection con = new SqlConnection(strCon);

//增删改执行语句，参数1是SQL语句，参数2是连接字符串
SqlCommand com = new SqlCommand(sql, con);

try
{
//打开数据连接
con.Open();

//执行查询，返回受影响行数
num = com.ExecuteNonQuery();
}
finally
{

//关闭数据库连接，无论是否正常执行
if (con.State == ConnectionState.Open)
con.Close();
}

//返回受影响行数
return num;

}
}
}