ceshi

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using Model;

namespace DAL
{
/// <summary>
/// 新闻类别表操作类
/// </summary>
public class CategoryDAO
{
private SQLHelper sqlhelper = null;
public CategoryDAO()
{
sqlhelper = new SQLHelper();
}

/// <summary>
/// 取出当前所有新闻分类
/// </summary>
/// <returns></returns>
public DataTable SelectAll()
{
DataTable dt = new DataTable();
string sql = "select * from category";
dt = sqlhelper.ExecuteQuery(sql, CommandType.Text);
return dt;
}

/// <summary>
/// 增加类别
/// </summary>
/// <param name="caName">类别名称</param>
/// <returns></returns>
public bool Insert(string caName)
{
bool flag = false;
string sql = "insert into category(name) values(@caName)";
SqlParameter[] paras = new SqlParameter[] {
new SqlParameter("@caName", caName)
};
int res = sqlhelper.ExecuteNonQuery(sql, paras, CommandType.Text);
if (res > 0)
{
flag = true;
}
return flag;
}

/// <summary>
/// 修改类别
/// </summary>
/// <param name="id">类别ID</param>
/// <param name="caName">类别名称</param>
/// <returns></returns>
public bool Update(Category ca)
{
bool flag = false;
string sql = "update category set [name]=@caName where id=@id";
SqlParameter[] paras = new SqlParameter[] {
new SqlParameter("@id", ca.Id),
new SqlParameter("@caName", ca.Name)
};
int res = sqlhelper.ExecuteNonQuery(sql, paras, CommandType.Text);
if (res > 0)
{
flag = true;
}
return flag;
}

/// <summary>
/// 删除类别（连同其下的新闻及新闻评论一起删除）
/// </summary>
/// <param name="id">类别ID</param>
/// <returns></returns>
public bool Delete(string id)
{
bool flag = false;
string sql = "delete from category where id=@id";
SqlParameter[] paras = new SqlParameter[] {
new SqlParameter("@id", id)
};
int res = sqlhelper.ExecuteNonQuery(sql, paras, CommandType.Text);
if (res > 0)
{
flag = true;
}
return flag;
}

/// <summary>
/// 判断类别名称是否已存在
/// </summary>
/// <param name="caName">类别名称</param>
/// <returns></returns>
public bool IsExists(string caName)
{
bool flag = false;
string sql = "select * from category where [name]='" + caName + "'";
DataTable dt = sqlhelper.ExecuteQuery(sql, CommandType.Text);
if (dt.Rows.Count > 0)
{
flag = true;
}
return flag;
}
}
}