Question

c# sql读取数据，两个combobox怎么数据绑定， 获取第一个的combobox1的值，又要在combobox用到该怎么写？

下面是我的代码
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
if (comboBox1.SelectedIndex > -1)
{
if (cn.State == System.Data.ConnectionState.Open)
{
cn.Close();
}
cn.Open();
string sql = "select c_name from Course where cct_ID=(select cct_id from CourseContentType where cct_NAME='@comboBox1')";
SqlCommand cmd = new SqlCommand(sql, cn);
cmd.Parameters.AddWithValue("@comboBox1", comboBox1.Text);
SqlDataAdapter adapter = new SqlDataAdapter(sql, cn);
DataSet ds = new DataSet();
comboBox2.Text = "==请选择==";
// 填充数据到DataSet
adapter.Fill(ds);
comboBox2.DataSource = ds.Tables[0];
//给combobox绑定数据源
comboBox2.DisplayMember = "c_id";
comboBox2.ValueMember = "c_name";
cn.Close();
}
}

Answer 1

 string sql = "select c_name,c_id from Course where 
 cct_ID=(select cct_id from CourseContentType where 
 cct_NAME=@comboBox1)";

你的绑定代码对了，只是在sql语句要加c_id和去掉@comboBox1两个单引号。