jsp two cascading delete the contents of a database table

<%
String userName1 = "sa";
String userPasswd = "111111";
String url = "jdbc: sqlserver :/ / localhost: 1433; databaseName = Data"; < br /> String tableName = "College";
/ / create connection and execute the query operation
Class.forName ("com.microsoft.sqlserver.jdbc.SQLServerDriver")
. newInstance ();
Connection conn = DriverManager.getConnection (url, userName1,
userPasswd);
Statement statement = conn.createStatement ( );
String sql2 = "SELECT distinct college FROM" + tableName;
ResultSet rs = statement.executeQuery (sql2);
%>

select faculties :

- Please Select -
<%
while (rs.next ())
{
%>
<% = rs.getString (1)%> ;
<%
}
rs.close ();
statement.close ();
conn.close () ;
%>


select specialty :

- Please Select -

< / div>

then go backstage after the show in the second query drop-down box , do1.jsp;

<% @ page language = "java" import = "java.util. * "pageEncoding =" gb2312 "%>
<% @ page import =" java.sql. *, java.io. * "%>
<%
String college = new String (request.getParameter ("college"). trim (). getBytes ("ISO8859_1"), "gb2312");

System.out.println (college);
String userName = "sa";
String userPasswd = "111111";
/ / need to connect database name
String dbName = "Data";
/ / table name
String tableName = "College";
String url ; = "jdbc: sqlserver :/ / localhost: 1433; databaseName = Data";
/ / create connection and execute the query operation
Class.forName ("com.microsoft.sqlserver.jdbc . SQLServerDriver ")
. newInstance ();
Connection conn = DriverManager.getConnection (url, userName,
userPasswd);
Statement statement = conn.createStatement ();
String sql = "SELECT major FROM" + tableName
+ "where college = '"+ college +"' ";
System.out.println (" sql: "+ sql);
ResultSet rs = statement . executeQuery (sql);

/ / get the data result set
response.setContentType ("text / html; charset = UTF-8");
response. setHeader ("Cache-Control", "no-cache");
PrintWriter pout = null;
pout = response.getWriter ();

pout.print ("[");
while (rs.next ())
{
try
{
pout.print ("'" + (rs.getString ("major")) + "',");

pout.print (",");
}
catch (Exception e)
{
e.printStackTrace ();
}
}
pout.print ("0]");
rs.close ();
statement.close ();
conn.close (); < br />
%>

get so much today , and finally engage in out, although there are many codes are not my , hey, are from the internet to find, then carefully change the change , and then two drop-down boxes can be displayed on demand , but the time and today shows a problem , do not show up : change9.jsp

<% @ page language = "java" ; import = "java.util. *" pageEncoding = "gb2312"%>
<% @ page import = "java.sql. *"%> < br /> <% @ include file = "connection.jsp"%>



< br />
<%
ResultSet rs1;
String sqlstr;
String select1 = new String (request.getParameter ("select1" ). trim (). getBytes ("ISO8859_1"), "gb2312");
String select2 = new String (request.getParameter ("select2"). trim (). getBytes (" ISO8859_1 ")," gb2312 ");

System.out.println (select1 + select2); shown here first select taken out , but the second has been undefined < / strong>
Statement pstm;
try
{

/ / [i] here is the operation of the database and then deleted , I will write , do not write / /
out.println ("");
}
catch (Exception e)
{
System.out.println (e);
}
%>