Question

请问SqlDataReader dr = cmd.ExecuteReader();这句话的cmd是什么？

Answer 1

cmd是SqlCommand的一个实例
SqlConnection conn = new SqlConnection();
conn.ConnectionString = "数据库连接字符串";
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "select * from TableName";
SqlDataReader reader = cmd.ExecuteReader();

追问

你肯定是个高手，要不我加你Q，你帮我看看咯

Answer 2

cmd 是类 System.Data.SqlClient.SqlCommand的实例

Answer 3

SqlCommand cmd=new SqlCommand();
SqlCommand的实例化

Answer 4

SqlCommand的对象。
类是SqlCommand cmd=new SqlCommand();

Answer 5

SqlCommand cmd=new SqlCommand();