c#连接sqlserver数据库、插入数据、从数据库获取时间示例

using System;
using System.Data.SqlClient;

namespace Test
{
    //连接数据库
    public class Connection
    {
        private static string connectionString =
            "Server = 192.168.1.222;" +
            "Database = Test;" +
            "User ID = Test;" +
            "Password = abc123;";

        /// <summary>
        /// 连接数据库
        /// </summary>
        /// <returns></returns>
        private SqlConnection ConnectionOpen()
        {
            SqlConnection conn = new SqlConnection(connectionString);
            conn.Open();
            return conn;
        }

        /// <summary>
        /// 向表(Table)中插入一条数据
        /// </summary>
        public void Insert(string value1, string value2, string value3, DateTime dateTime)
        {
            SqlConnection conn = ConnectionOpen();
            string sql =
                "insert into Table(row1, row2, row3, DateTime) values ('" +
                value1 + "', '" + value2 + "', '" + value3 + "', '" + dateTime + "')";
            SqlCommand comm = new SqlCommand(sql, conn);
            comm.ExecuteReader();
　　
            conn.Close();
        }

        /// <summary>
        /// 从数据库中获取当前时间
        /// </summary>
        /// <returns></returns>
        public DateTime GetDateTimeFromSQL()
        {
            SqlConnection conn = ConnectionOpen();
            string sql = "select getdate()";
            SqlCommand comm = new SqlCommand(sql, conn);
            SqlDataReader reader = comm.ExecuteReader();
            DateTime dt;
            if (reader.Read())
            {
                dt = (DateTime)reader[0];
                conn.Close();
                return dt;
            }
            conn.Close();
            return DateTime.MinValue;
        }
    }
}

/*
* 说明
* 功能说明:数据访问封装。所有数据都要通过这个类定义的dbConnection访问数据库。
* 同时，定义了通用的cmd，以及cmd常用的访问存储过程的方法RunPro  
*   
* 作者: RogerWang
*   
* 创建日期:2006-02-15
*   
*/

using System;
using System.Data;
using System.Data.SqlClient;

namespace insurer
{
  /// <summary>
  /// DataAccess 的摘要说明。
  /// </summary>
  public class DataAccess
  {
    private readonly string SQLCONNECTSTR = "server=(local);uid=sa;pwd=lwrong;database=insurer";
    private SqlConnection dbConnection;
    private readonly string RETUENVALUE = "RETURNVALUE";   

    //判断要不要启动事务
                private bool startrans = false;

    //为解决多笔数据导入的问题,特添加的事务处理属性
    private SqlTransaction trans = null;

               
    //定义是否启动事务属性
    public bool StartTrans
    {
      get
      {
        return startrans;
      }
      set
      {
        startrans = value;
      }
    }

    //定义事务
    public SqlTransaction Trans
    {
      get
      {
        return trans;
      }
      set
      {
        if (value != null)
        {
          trans = value;
        }
      }
    }

    //创建打开dbConnection对象
    public void OpenConnection()
    {
      if ( dbConnection == null )
      {
        dbConnection = new SqlConnection(SQLCONNECTSTR);
      }

      if ( dbConnection.State == ConnectionState.Closed )
      {
        try
        {
          dbConnection.Open();
        }
        catch(Exception ex)
        {
          SystemError.SystemLog(ex.Message);
        }
        finally
        {
        }
      }
    }

    //释放dbConnection对象
    public void CloseConnection()
    {
      if (dbConnection != null)
      {
        if (dbConnection.State == ConnectionState.Open)
        {
          dbConnection.Dispose();
          dbConnection = null;
        }
      }
    }

    //

    //创建cmd,注意dbconnection在该函数中创建，但没有在这函数中释放。
    //在正确的面向对象设计方法中，对象应该是谁创建，谁就应该负责释放。按这个观点，这个过程有些不安全!!!!
        private SqlCommand CreateCommand(string ProName,SqlParameter[] prams)
    {
      OpenConnection();
      SqlCommand cmd = new SqlCommand(ProName,dbConnection);
      cmd.CommandType = CommandType.StoredProcedure;

      //如果进行事务处理,那么对cmd的Transaction的事务赋值
      if (StartTrans)
      {
        cmd.Transaction = Trans;
      }

      if ( prams != null)
      {
        foreach(SqlParameter parameter in prams)
        {
          cmd.Parameters.Add(parameter);
        }
      }

      //cmd.Parameters.Add(

      return cmd;

    }

    /// <summary>
    /// 创建cmd,并执行相应的操作。 然后释放cmd!
    ///   
    /// 该函数是执行cmd没有返回值，且没有参数的方法。
    /// </summary>
    /// <param name="ProName"></param>
    public bool RunProc(string ProName)
    {
      SqlCommand cmd = CreateCommand(ProName,null);

      bool k = false;
      try
      {
        k = (bool)cmd.ExecuteScalar();
      }
      catch(Exception ex)
      {
        SystemError.SystemLog(ex.Message);
      }
      finally
      {
        cmd.Dispose();
      }
      return k;

    }

    /// <summary>
    /// 创建cmd,并执行相应的操作。 然后释放cmd!
    ///   
    /// 该函数是执行cmd没有返回值,但有参数的方法。
    /// </summary>
    /// <param name="ProName"></param>
    /// <param name="prams"></param>
    public bool RunProc(string ProName,SqlParameter[] prams)
    {
      SqlCommand cmd = CreateCommand(ProName,prams);

      bool k = false;
      try
      {
        k = (bool) cmd.ExecuteScalar();
      }
      catch(Exception ex)
      {
        SystemError.SystemLog(ex.Message);
      }
      finally
      {   
        cmd.Dispose();
        //Close();
      }
      return k;
    }

    /// <summary>
    /// 创建cmd,并执行相应的操作。 然后释放cmd!
    ///   
    /// 该函数是执行cmd带有返回值,但没有参数的方法。   
    /// </summary>
    /// <param name="ProName"></param>
    /// <param name="dataReader"></param>
    public void RunProc(string ProName,out SqlDataReader dataReader)
    {
      SqlCommand cmd = CreateCommand(ProName,null);
      dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
      try
      {

      }
      catch(Exception ex)
      {
        SystemError.SystemLog(ex.Message);
      }
      finally
      {
        cmd.Dispose();
      }
    }

    /// <summary>
                /// 创建cmd,并执行相应的操作。 然后释放cmd!
    ///   
    /// 该函数是执行cmd带有返回值,且有参数的方法。
    /// </summary>
    /// <param name="ProName"></param>
    /// <param name="prams"></param>
    /// <param name="dataReader"></param>
    public void RunProc(string ProName,SqlParameter[] prams,out SqlDataReader dataReader)
    {
      SqlCommand cmd = CreateCommand(ProName,prams);
      dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
      try
      {

      }
      catch(Exception ex)
      {
        SystemError.SystemLog(ex.Message);
      }
      finally
      {
        cmd.Dispose();
      }
    }

    /// <summary>
    /// 创建cmd的参数
    /// 该方法的思路就是按条件生成一个SqlParameter对象。
    /// 生成对象后，再给对象赋相应的返回值类型
    /// </summary>
    /// <param name="ParamName"></param>
    /// <param name="DbType"></param>
    /// <param name="size"></param>
    /// <param name="direction"></param>
    /// <param name="Value"></param>
    /// <returns></returns>
    public SqlParameter CreateParam(string ParamName, SqlDbType DbType, int size,ParameterDirection direction,object Value)
    {
      SqlParameter param;

      if (size > 0)
      {
        param = new SqlParameter(ParamName,DbType,size);
      }
      else
      {
        param = new SqlParameter(ParamName,DbType);
      }

      param.Direction = direction;

      param.Value = Value;

      return param;
    }

    /// <summary>
    /// 创建cmd的输入参数
    /// </summary>
    /// <param name="ParamName"></param>
    /// <param name="DbType"></param>
    /// <param name="size"></param>
    /// <param name="Value"></param>
    /// <returns></returns>
    public SqlParameter CreateInParam(string ParamName, SqlDbType DbType, int size, object Value)
    {
      return CreateParam(ParamName,DbType,size,ParameterDirection.Input,Value);
    }

    /// <summary>
    /// 创建cmd的输出参数
    /// </summary>
    /// <param name="ParamName"></param>
    /// <param name="DbType"></param>
    /// <param name="size"></param>
    /// <returns></returns>
    public SqlParameter CreateOutParam(string ParamName, SqlDbType DbType, int size)
    {
      return CreateParam(ParamName,DbType,size,ParameterDirection.Output,null);
    }

    /// <summary>
    /// 创建cmd带有返回值的参数
    /// </summary>
    /// <param name="ParamName"></param>
    /// <param name="DbType"></param>
    /// <param name="size"></param>
    /// <returns></returns>
    public SqlParameter CreateReturnParam(string ParamName,SqlDbType DbType, int size)
    {
      return CreateParam(ParamName,DbType,size,ParameterDirection.ReturnValue,null);
    }

    //开始一个事务
    public void BeginTrans()
    {
      OpenConnection();

      Trans = dbConnection.BeginTransaction(IsolationLevel.Serializable);
    }

    public void Commit()
    {
      if (Trans != null)
      {
        Trans.Commit();
      }
    }

    public void Rollback()
    {
      if (Trans != null)
      {
        Trans.Rollback();
      }
    }
  }
}