diff --git "a/23\346\275\230\350\276\211\350\276\276/\344\275\234\344\270\232/\347\254\254\345\233\233\347\253\240/.keep" "b/23\346\275\230\350\276\211\350\276\276/\344\275\234\344\270\232/\347\254\254\345\233\233\347\253\240/.keep"
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git "a/23\346\275\230\350\276\211\350\276\276/\344\275\234\344\270\232/\347\254\254\345\233\233\347\253\240/WebForm1.aspx(1).cs" "b/23\346\275\230\350\276\211\350\276\276/\344\275\234\344\270\232/\347\254\254\345\233\233\347\253\240/WebForm1.aspx(1).cs"
new file mode 100644
index 0000000000000000000000000000000000000000..c0541deae58be4515495de8164253a2cd1c16072
--- /dev/null
+++ "b/23\346\275\230\350\276\211\350\276\276/\344\275\234\344\270\232/\347\254\254\345\233\233\347\253\240/WebForm1.aspx(1).cs"
@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Web;
+using System.Web.UI;
+using System.Web.UI.WebControls;
+
+namespace WebApplication1
+{
+    public partial class WebForm1 : System.Web.UI.Page
+    {
+        protected void Page_Load(object sender, EventArgs e)
+        {
+            if (!Page.IsPostBack) {
+                SqlDataSource1.SelectCommand = "select * from city where type=1 ";
+
+                SqlDataSource2.SelectCommand = "select * from city where type=2 and pid=2";
+                SqlDataSource3.SelectCommand = "select * from city where type=3 and pid in (select id from city where type = 2 and pid = 2)";
+            }
+
+        }
+
+        protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
+        {
+            SqlDataSource2.SelectCommand = "select * from city where type=2 and pid=" + DropDownList1.SelectedValue;
+            SqlDataSource3.SelectCommand = "select * from city where type=3 and pid in (select id from city where type = 2 and pid = " + DropDownList1.SelectedValue+")";
+        }
+
+        protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
+        {
+            SqlDataSource3.SelectCommand = "select * from city where type=3 and pid =" + DropDownList2.SelectedValue;
+        }
+
+        protected void DropDownList3_SelectedIndexChanged(object sender, EventArgs e)
+        {
+
+        }
+    }
+}
\ No newline at end of file