pass a parameter from sql table to jsp page.

**kirti bansal** · 04-24-2012, 10:16 AM

im new to jsp. i ve a table, that i can view easily on browser using jsp. now i want to pass only 1 value of a particular column on click. i tried assigning a parameter to that value and directing its action to main page where im storing that parameter in a string with request.getParameter ("parameter"). but when im passing this string to fetch values in the table, im getting null. plz help..

im passing parameter like

<td> <input name="<portlet:namespace />cid" value= "<%=rst.getString("ID")%>"/></td>

and retrieving it in details page as:
String id= request.getParameter("cid");

i want to use this id to fetch values from table as below:
String s1 =("SELECT SMILES FROM CHEMICAL_LIBRARY WHERE ID= '"+id+"'" );
....
im getting a null value. but a correct result if i pass id manually like 1 or 2. all connections and drivers are ok. the problem is in passing the parameter. plz help

**Tolls** · 04-24-2012, 12:29 PM

What does the html for that input field look like on the client?
Also, it's not a good idea to do database interaction in your JSP. You ought to go via a servlet, whose job is to get the data needed by the JSP and then forward.
It would be a lot easier to debug that way.

**kirti bansal** · 04-25-2012, 06:08 AM

thanks 4 the reply!!
the page showing the database looks like this:

pass a parameter from sql table to jsp page.-view.jpg

when i click view button, i want that particular value in SMILES column to be passed. i gave a parameter name to id value while retrieving it from database and passed it to the final page. in the final page after storing the value in a string as request.getParameter("parameter"), im passing this in SQL statement as "SELECT SMILES FROM CHEMICAL_LIBRARY WHERE ID= '"+id+"'" ); but im getting null value. if manually i pass id values like 1, 2 etc, im getting desired results. il definitely try it via servlet, once i get the actual concept.

**Tolls** · 04-25-2012, 09:29 AM

No, I asked for the HTML for that field, not a picture of the page in the browser.

Also, are you saying that 'id' is null on the server? That is, 'request.getParameter("cid")' returns null?

**kirti bansal** · 04-25-2012, 11:43 AM

Originally Posted by Tolls

No, I asked for the HTML for that field, not a picture of the page in the browser.

Also, are you saying that 'id' is null on the server? That is, 'request.getParameter("cid")' returns null?

the HTML is like this:
<html>
<body>

<link rel="stylesheet" type="text/css" href="style.css" />
<table border="1" cellspacing="0" cellpadding="0">
<tr>
<td><B>Id</B></td>
<td><B>SMILES</B></td>
<td><B>Chemical name</B></td>
<td><B>IUPAC</B></td>
<td><B>MOL_Formula</B></td>
<td><B>Mol_Mass(g/mol)</B></td>
<td><B>Use</B></td>
</tr>

<% while(rst.next())
{
%>

<tr>
<td>
<input name="cid" value= "<%=rst.getString("ID")%>"/> </td>

<td><%=rst.getString("SMILES")%>
<form method="post" action="view.jsp">

<input type="submit" value="view"/>
</form></td>
<td> <%=rst.getString("CHEMICAL_NAME")%></td>
<td> <%=rst.getString("IUPAC")%></td>
<td> <%=rst.getString("MOL_FORMULA")%></td>
<td> <%=rst.getString("mol_mass(g/mol)")%></td>
<td> <%=rst.getString("USE")%></td>

<%} %>
</tr>
</table>
</body>
</html>

yes im getting a null value when im passing "cid" parameter as 'request.getParameter("cid")' in final page.

**Tolls** · 04-25-2012, 12:08 PM

That's not the html on the client.
What does the source for that input tag look like on the client.
Indeed the whole form.

In fact, saying that...that tag is not in the form, so of course it's not going to be submitted.

**kirti bansal** · 04-25-2012, 12:42 PM

ya thanku so much i got it.. i was not including this parameter in the form.. thanks!

**DarrylBurke** · 04-25-2012, 12:50 PM

BB Code List - Java Programming Forum

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**nicephotog** · 05-31-2012, 09:32 AM

Do you connect to the database during view.jsp processing???
you create a statement too?? and get DriverManager .... e.t.c
then return a ResultSet???

Then you assign put() a property onto view.jsp (beats me why you don't take the field value from the ResultSet and put it into a "global variable" if the JSP code is in your JSP page)
note: view.jsp should appear like
view.jsp?cid=whatever+goes+here%20or%20here