Winform 开发框架源码 devexpress 管理系统源码 C# .NET 多主题通用权限管理系统
部分数据库源码
namespace S1Hotel
{
class DBHelper
{
//创建数据库连接
private static string str = @“Data Source=.;Initial Catalog=S1Hotel;Integrated Security=True”;
private SqlConnection con = new SqlConnection(str);
/// <summary>/// 查询多个值的方法/// </summary>/// <param name="str"></param>/// <param name="sql"></param>/// <returns></returns>public SqlDataReader SelectDataReader(string sql){con.Open();SqlCommand com = new SqlCommand(sql, con);return com.ExecuteReader(CommandBehavior.CloseConnection);//返回SqlDataReader关闭SqlConnection对象连接}/// <summary>/// 备用关闭数据库/// </summary>public void CloseConnection(){con.Close();}/// <summary>/// 增删改/// </summary>/// <param name="sql">SQL语句</param>/// <returns></returns>public int ExecuteSQLCommand(string sql){con.Open();SqlCommand com = new SqlCommand(sql, con);int a = com.ExecuteNonQuery();con.Close();return a;}/// <summary>/// 查询一张表的数据/// </summary>/// <param name="sql">SQL语句</param>/// <param name="biaoMing"></param>/// <returns></returns>public DataSet GetDataSet(string sql, string biaoMing){SqlDataAdapter da = new SqlDataAdapter(sql, con);DataSet ds = new DataSet();da.Fill(ds, biaoMing);return ds;}/// <summary>/// 查询单个值并返回int类型/// </summary>/// <param name="sql"></param>/// <returns></returns>public int GetSingleIntValue(string sql){con.Open();SqlCommand com = new SqlCommand(sql, con);int a = 0;var t = com.ExecuteScalar();//当com.ExecuteScalar()等于空时就返回0；if (t == DBNull.Value || t == null){}else{a = (int)com.ExecuteScalar();}con.Close();return a;}/// <summary>/// 查询单个值并返回double类型/// </summary>/// <param name="sql"></param>/// <returns></returns>public double GetSingleDoubleValue(string sql){con.Open();SqlCommand com = new SqlCommand(sql, con);double a = 0;var t = com.ExecuteScalar();//当com.ExecuteScalar()等于空时就返回0；if (t == DBNull.Value || t == null){}else{a = Convert.ToDouble(com.ExecuteScalar());}con.Close();return a;}/// <summary>/// 计算时间重叠/// </summary>/// <param name="a"></param>/// <param name="b"></param>/// <param name="x"></param>/// <param name="y"></param>/// <returns></returns>public bool CalcTimeOverlap(DateTime a, DateTime b, DateTime x, DateTime y){//时间无重叠 return b >= x && y >= a;/*if ((b < x) || (y < a))return false;return true;*/}}
}
需要源码的私信
