从数据库获取数据

  //从数据库获取数据

 

public static DataTable  GetData0()

       {

           SqlConnection sqlcon = new SqlConnection();

           sqlcon.ConnectionString = "Catalog=JinKeLi;Data Source=(local);uid=sa;pwd=123";

           if (sqlcon.State == ConnectionState.Closed)

           {

               sqlcon.Open();

           }

           //接下来初始化命令

           SqlCommand cmd = new SqlCommand();

           cmd.Connection = sqlcon;

           cmd.CommandType = CommandType.Text;

           cmd.CommandText = "select * from Tb_Config";

           //用于执行数据的插入，更新，删除的操作；返回被影响的行数

           int i = cmd.ExecuteNonQuery();

           if (i > 0)

           {

               Console.WriteLine("<script>alert('操作成功')</script>");

           }

           //用于查询最大值只需返回一条数据情况下的操作，返回的是首行第一行的数据

           object obj = cmd.ExecuteScalar();

           DataSet ds = new DataSet();

           DataTable dt = new DataTable();

           SqlDataAdapter sda = new SqlDataAdapter();

           sda.SelectCommand = cmd;//SelectCommand用于获取cmd命令的执行的操作

           sda.Fill(dt);

           return dt;

 

       }

        //若要创建 SqlDataReader，必须调用 SqlCommand 对象的 ExecuteReader 方法，

       //而不要直接使用构造函数

       public static void GetData1()

       {

           string str = "Data Source=.;Initial Catalog=JinLeLi;Initial Security=true;";

           string sql = "select * from Tb_Config";

           SqlConnection conn = new SqlConnection();

           conn.Open();

           SqlCommand comm = new SqlCommand(sql, conn);

           DataSet ds = new DataSet();

           SqlDataReader dr = comm.ExecuteReader();

           if (dr.Read())

           {

               //下面的俩中方法都可以获取数据

               //根据序列

               this.TextBox1.Text = dr.GetString(1);

               this.TextBox2.Text = dr.GetString(2);

 

               //根据字段

               this.TextBox1.Text = dr.GetString(dr.GetOrdinal("Name"));

               this.TextBox2.Text = dr.GetInt32(dr.GetOrdinal("Age").ToString());

           }

           //用到SQLDataReader要用循环输出

           while(dr.Read())

           {

               Console.WriteLine(dr["Name"]);

               Console.WriteLine(dr["Age"]);

           }

 

           dr.Close();

           if (conn.State == ConnectionState.Open)

           {

               conn.Close();

           }

 

 

       }

转载于:https://www.cnblogs.com/ZkbFighting/p/8137997.html