SqlConnection myConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["jiaoxuedbConnectionString"].ConnectionString);
string v = Request.Form["tj"];//那个 select的值,你可以用他来作具体的操
string sql = "select distinct xueyuan from tongji ";
SqlDataAdapter myAdapter = new SqlDataAdapter(sql, myConnection);
myConnection.Open();
DataSet dataSet = new DataSet();
myAdapter.Fill(dataSet, "tongji");
myConnection.Close();
jieguo.DataSource = dataSet.Tables["tongji"].DefaultView;
jieguo.DataTextField =xueyuan; //dropdownlist的Text的字段 //jieguo.DataValueField = "sno";//dropdownlist的Value的字段
jieguo.DataBind();
现在这里面的sql语句是写死的,但是我想让sql语句通过以用户点击的下来列表中的值得value为列名在数据库中查出相应的数据,显示在另一个下拉列表中。这里咋写:
string sql = "select distinct xueyuan from tongji ";
jieguo.DataTextField =xueyuan;
string sql = "select distinct xueyuan from tongji where 字段='"+jieguo.Selectvalue+"'";
表名 TableName
条件字段名 SearchTaget
条件值 SearchValue
都通过参数传递进来。 public bool SelectTaget(string ColumnName, string TableName,string SearchTaget, string SearchValue)
{
string connStr = DAL.SQLConn.connStr;
using (SqlConnection conn = new SqlConnection(connStr))
{
conn.Open();
string cmdStr = "select [" + ColumnName + "] from [" + TableName + "] where [" + SearchTaget + "] = '" + SearchValue + "'";
SqlCommand cmd = new SqlCommand(cmdStr, conn);
SqlDataReader reader = cmd.ExecuteReader();
return reader.Read();
}
}
你的代码结构要写过,你传进去查询的字段是什么名称,这里就填写什么字段名称。
字段的话 引号呢?jieguo.DataTextField ="xueyuan";
sql+=" "+jieguo.SelectedValue+" from tongji "