Question

c#数据操作问题

objCmd.CommandText = "select Nname from Student where Nname = '" + textBox1.Text + "'";
objCmd.CommandType = CommandType.Text;
objCmd.Connection = objCn;
objCmd.EndExecuteNonQuery();
if (objCmd.EndExecuteNonQuery == true)
{

}
我想判断textBox1里面的值在数据库中存不存在
那我应该用那一个勒?

Answer 1

objCmd.CommandText = "select Nname from Student where Nname = '" + textBox1.Text + "'";
datareader=objCmd.ExecuteReader();
if(datareader.HasRows==true) //判断Sql语句的返回值.
{
//说明textBox1.Text的值存在
}

Answer 2

cmd执行后有返回值的呀~只要判断一下返回值为什么就可以了呀 ~~

Answer 3

既然你用了SELECT是查询为什么要用EndExecuteNonQuery();呢?