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WHERE clause in SQL statement used in JSP page

Posted on 2002-05-29
14
5,267 Views
Last Modified: 2008-03-17
Hi All,

  Well, I am much closer, but I can not seem to get my "WHERE" clause to work. Jakarta-Tomcat seems to complain about a missing operator. I think I need to add quotes, but every combination I try gives my syntax errors. What could be wrong with my WHERE statement?


<%@include file="myobjects.jsp"%>
<%@ page import="java.sql.*" %>

<%
String sDefinition = "";
String sLabelString = "";

sLabelString = request.getParameter("currlabel").trim();

//Load the JDBC-ODBC bridge driver
try {
     Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver");
} catch( ClassNotFoundException ee) {  
     ee.printStackTrace();
}
 
//open a data source name by means of the jdbcodbcdriver.
// ODBC data source name
String dsn = "jdbc:odbc:paysyshelpmenu";
String user = "admin";
String password = "";

// Connect to the database
Connection con = DriverManager.getConnection(dsn, user, password);

// Shut off autocommit
con.setAutoCommit(false);
       

//executing a query on the opened connection.
Statement stmt; // SQL statement object
String query;   // SQL select string
ResultSet rs;   // SQL query results
boolean more;   // "more rows found" switch      
String v1;       // Temporary storage results  
String whereClause = "WHERE ScreenID = " + myobj.getScreenId() + " AND 3270Literal = " + sLabelString + "";

System.out.println("Screen ID = " + myobj.getScreenId());
System.out.println("Label = " + sLabelString);
System.out.println("Where Clause = " + whereClause);

Vector results = new Vector( 10 );

query = "SELECT Definition FROM Employees " + whereClause;
System.out.println("Query = " + query);        


//try {
       stmt = con.createStatement();
       rs = stmt.executeQuery(query);
   
       // Check to see if any rows were read
       more = rs.next();
       if (!more) {

            System.out.println("No rows found.");
            return;

        }

        // Loop through the rows retrieved from the query
        while (more) {

         v1 = "Definition: " + rs.getString("Definition");
         sDefinition = rs.getString("Definition");

            System.out.println( v1 );
            System.out.println("");    

            results.addElement( v1 + "\n");
            more = rs.next();

        }

        rs.close();
     stmt.close();

//} catch (SQLException e) {
//     System.out.println("" + results.size() + " results where found.");
//}


%>

<html>
<title>Whats This</title>
<body>
<p> <%=sDefinition %> </p>
</body>
</html>
0
Comment
Question by:DoughBoy
  • 6
  • 5
  • 2
  • +1
14 Comments
 
LVL 6

Expert Comment

by:kotan
ID: 7043445
In sql statement, string is located between ' (single quote)

String whereClause = "WHERE ScreenID = " + myobj.getScreenId() + " AND 3270Literal = " + sLabelString
+ "";

-->

String whereClause = "WHERE ScreenID = '" + myobj.getScreenId() + "' AND 3270Literal = '" + sLabelString
+ "'";
0
 
LVL 92

Expert Comment

by:objects
ID: 7043612
Using PreparedStatement and placeholders avoids all the problems with quoting and formating etc. Let me know if you'd like more info.
0
 

Author Comment

by:DoughBoy
ID: 7044692
Hi Kotan,
Thanks, but I tried that and it did not work.

Objects, I could use all the advice you can offer. Do you have some sample code?

Thanks
DoughBoy
0
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LVL 19

Expert Comment

by:cheekycj
ID: 7044699
I agree with objects.  Use PreparedStatement.  Not only does it remove issues with formatting for SQL it also is a performance enhancement (supposedly - though I haven't done any perf testing or profiling on it)

Also you don't want to use rs.next() to check if there are any rows. rs.next() moves the cursor to the next row, a better approach is to use a counter.

Here is your basic PreparedStatement setup:

try {
String sDefinition = "";
String sLabelString = "";

sLabelString = request.getParameter("currlabel").trim();

//Load the JDBC-ODBC bridge driver
try {
    Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver");
} catch( ClassNotFoundException ee) {  
    ee.printStackTrace();
}
 
//open a data source name by means of the jdbcodbcdriver.
// ODBC data source name
String dsn = "jdbc:odbc:paysyshelpmenu";
String user = "admin";
String password = "";
   // Connect to the database
  Connection con = DriverManager.getConnection(dsn, user, password);

  // Shut off autocommit
  con.setAutoCommit(false);

  String query = "SELECT Definition FROM Employees WHERE ScreenID = ? AND 3270Literal = ?";
  PreparedStatement ps = con.prepareStatement(query);
  ResultSet rs = null;
  ps.setLong(1, myobj.getScreenId());
  ps.setString(2, sLabelString);
  rs = ps.executeQuery();
  int count = 0;
  while (rs.next()) {
        v1 = "Definition: " + rs.getString("Definition");
        sDefinition = rs.getString("Definition");

        System.out.println( v1 );
        System.out.println("");    

        results.addElement( v1 + "\n");

  }
  if (count == 0)
      System.out.println("No results found");
  rs.close();
  ps.close();
  con.close();
} catch (Exception e) {e.printStackTrace();}

HTH,
CJ
0
 

Author Comment

by:DoughBoy
ID: 7044817
Thanks for your suggestion, CJ.

This is the error I receive:

....

Root cause:
java.sql.SQLException: [Microsoft][ODBC Microsoft Access Driver] Syntax error (m
issing operator) in query expression 'ScreenID = Pa_RaM000 AND 3270Literal = Zip Code'.
....
0
 
LVL 19

Expert Comment

by:cheekycj
ID: 7044822
Oh I didn't know that Screen ID was a String.

change the following line:
ps.setLong(1, myobj.getScreenId());

to

ps.setString(1, myobj.getScreenId());

CJ
0
 

Author Comment

by:DoughBoy
ID: 7044876
Still same error...

Thanks, I saw that and changed it too. What is wierd is that it looks like myobj.getScreenId() is being applied twice in the query string. And sLabelString is not even used.
0
 
LVL 19

Expert Comment

by:cheekycj
ID: 7045190
can you post your current code and exact stack trace java outputs.

CJ
0
 

Author Comment

by:DoughBoy
ID: 7045220
code:

<%@include file="myobj.jsp"%>
<%@ page import="java.io.*" %>
<%@ page import="java.sql.*" %>

<%
String sDefinition = "";
String sLabelString = "";

sLabelString = request.getParameter("currlabel").trim();
System.out.println ("Label String: " + sLabelString);

//Load the JDBC-ODBC bridge driver
try {
      Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver");
} catch( ClassNotFoundException ee) {  
      ee.printStackTrace();
}
 
//open a data source name by means of the jdbcodbcdriver.
// ODBC data source name
String dsn = "jdbc:odbc:helpmenu";
String user = "admin";
String password = "";

// Connect to the database
Connection con = DriverManager.getConnection(dsn, user, password);

// Shut off autocommit
con.setAutoCommit(false);
       
String query = "SELECT Definition FROM GUIHelpEnglish WHERE ScreenID = ? AND 3270Literal = ?";
PreparedStatement ps = con.prepareStatement(query);

System.out.println(query);

ResultSet rs = null;
ps.setString(1, myobj.getScreenId());
//ps.setString(1, "SCREEN01");
ps.setString(2, sLabelString);
//ps.setString(2, "PLAN");

rs = ps.executeQuery();

//try {
 int count = 0;
 while (rs.next()) {
       sDefinition = rs.getString("Definition");

       System.out.println(sDefinition);    

 }
if (count == 0) {
     System.out.println("No results found");
}
 
rs.close();
ps.close();
con.close();

//} catch (SQLException e) {
//}


%>

<html>
<title>Whats This</title>
<body>
<p> <%=sDefinition %> </p>
</body>
</html>


browser message: (NOTICE THE STRINGS CHANGE TO SOME STRANGE VALUE - I thought the screen ID was sent twice, but both strings get messed up. I don't know where Pa_RaM000 came from. The values get passed correctly from previous pages. And Why would single quotes be wrapped around the entire ps?)

Error: 500
Location: /mydemo/my.jsp
Internal Servlet Error:

javax.servlet.ServletException: [Microsoft][ODBC Microsoft Access Driver] Syntax error (missing operator) in query expression 'ScreenID = Pa_RaM000 AND 3270Literal = Pa_RaM001'.
      at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:459)
      at _0002fwhatsthis_0002ejspwhatsthis_jsp_8._jspService(_0002fwhatsthis_0002ejspwhatsthis_jsp_8.java:203)
      at com.sabratec.servlet.GXAbstractJspPageServlet.service(Unknown Source)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
      at org.apache.jasper.servlet.JspServlet$JspCountedServlet.service(JspServlet.java:130)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
      at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:282)
      at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:429)
      at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:500)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
      at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405)
      at org.apache.tomcat.core.Handler.service(Handler.java:287)
      at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
      at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812)
      at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758)
      at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213)
      at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
      at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501)
      at java.lang.Thread.run(Thread.java:484)
Root cause:
java.sql.SQLException: [Microsoft][ODBC Microsoft Access Driver] Syntax error (missing operator) in query expression 'ScreenID = Pa_RaM000 AND 3270Literal = Pa_RaM001'.
      at sun.jdbc.odbc.JdbcOdbc.createSQLException(JdbcOdbc.java:6031)
      at sun.jdbc.odbc.JdbcOdbc.standardError(JdbcOdbc.java:6188)
      at sun.jdbc.odbc.JdbcOdbc.SQLExecute(JdbcOdbc.java:2533)
      at sun.jdbc.odbc.JdbcOdbcPreparedStatement.execute(JdbcOdbcPreparedStatement.java:217)
      at sun.jdbc.odbc.JdbcOdbcPreparedStatement.executeQuery(JdbcOdbcPreparedStatement.java:92)
      at _0002fwhatsthis_0002ejspwhatsthis_jsp_8._jspService(_0002fwhatsthis_0002ejspwhatsthis_jsp_8.java:164)
      at com.sabratec.servlet.GXAbstractJspPageServlet.service(Unknown Source)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
      at org.apache.jasper.servlet.JspServlet$JspCountedServlet.service(JspServlet.java:130)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
      at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:282)
      at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:429)
      at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:500)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
      at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405)
      at org.apache.tomcat.core.Handler.service(Handler.java:287)
      at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
      at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812)
      at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758)
      at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213)
      at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
      at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501)
      at java.lang.Thread.run(Thread.java:484)



Errors in TOMCAT CONSOLE:
Label String: PLAN
SELECT Definition FROM Employees WHERE ScreenID = ? AND 3270Literal = ?
2002-05-30 13:55:12 - Ctx( /mydemo ): Exception in: R( /mydemo +
 /my.jsp + null) - javax.servlet.ServletException: [Microsoft][ODBC Micro
soft Access Driver] Syntax error (missing operator) in query expression 'ScreenI
D = Pa_RaM000 AND 3270Literal = Pa_RaM001'.
        at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageCon
textImpl.java:459)
        at _0002fmy_0002ejspwhatsthis_jsp_8._jspService(_0002fmy_0
002ejspmy_jsp_8.java:203)
 
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at org.apache.jasper.servlet.JspServlet$JspCountedServlet.service(JspSer
vlet.java:130)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspSer
vlet.java:282)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:4
29)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:500)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:4
05)
        at org.apache.tomcat.core.Handler.service(Handler.java:287)
        at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372
)
        at org.apache.tomcat.core.ContextManager.internalService(ContextManager.
java:812)
        at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758
)
        at org.apache.tomcat.service.http.HttpConnectionHandler.processConnectio
n(HttpConnectionHandler.java:213)
        at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:
416)
        at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java
:501)
        at java.lang.Thread.run(Thread.java:484)
Root cause:
java.sql.SQLException: [Microsoft][ODBC Microsoft Access Driver] Syntax error (m
issing operator) in query expression 'ScreenID = Pa_RaM000 AND 3270Literal = Pa_
RaM001'.
        at sun.jdbc.odbc.JdbcOdbc.createSQLException(JdbcOdbc.java:6031)
        at sun.jdbc.odbc.JdbcOdbc.standardError(JdbcOdbc.java:6188)
        at sun.jdbc.odbc.JdbcOdbc.SQLExecute(JdbcOdbc.java:2533)
        at sun.jdbc.odbc.JdbcOdbcPreparedStatement.execute(JdbcOdbcPreparedState
ment.java:217)
        at sun.jdbc.odbc.JdbcOdbcPreparedStatement.executeQuery(JdbcOdbcPrepared
Statement.java:92)
        at _0002fmy_0002ejspmy_jsp_8._jspService(_0002fmy_0
002ejspmy_jsp_8.java:164)

        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at org.apache.jasper.servlet.JspServlet$JspCountedServlet.service(JspSer
vlet.java:130)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspSer
vlet.java:282)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:4
29)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:500)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:4
05)
        at org.apache.tomcat.core.Handler.service(Handler.java:287)
        at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372
)
        at org.apache.tomcat.core.ContextManager.internalService(ContextManager.
java:812)
        at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758
)
        at org.apache.tomcat.service.http.HttpConnectionHandler.processConnectio
n(HttpConnectionHandler.java:213)
        at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:
416)
        at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java
:501)
        at java.lang.Thread.run(Thread.java:484)


0
 
LVL 19

Expert Comment

by:cheekycj
ID: 7045604
When you used your string constants:

ps.setString(1, "SCREEN01");
ps.setString(2, "PLAN");

did it work?

also replace your System.out.println(query) with:

System.out.println(query + ":" + myobj.getScreenId() + "," + sLabelString);

What gets outputted?

CJ


0
 
LVL 19

Expert Comment

by:cheekycj
ID: 7045621
also add this AFTER the ps.setString() statements.

System.out.println(ps.toString());

CJ
0
 
LVL 19

Expert Comment

by:cheekycj
ID: 7045635
Another Option to try if you just want to get it to work and don't care about the benefits of prepared statements is this:


<%@include file="myobj.jsp"%>
<%@ page import="java.io.*" %>
<%@ page import="java.sql.*" %>

<%
String sDefinition = "";
String sLabelString = "";

sLabelString = request.getParameter("currlabel").trim();
System.out.println ("Label String: " + sLabelString);

//Load the JDBC-ODBC bridge driver
try {
     Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver");
} catch( ClassNotFoundException ee) {  
     ee.printStackTrace();
}
 
//open a data source name by means of the jdbcodbcdriver.
// ODBC data source name
String dsn = "jdbc:odbc:helpmenu";
String user = "admin";
String password = "";

// Connect to the database
Connection con = DriverManager.getConnection(dsn, user, password);

// Shut off autocommit
con.setAutoCommit(false);
     
Statement stmt = con.createStatement();

System.out.println(query + ":" + myobj.getScreenId() + "," + sLabelString);

ResultSet rs = stmt.executeQuery("SELECT Definition FROM GUIHelpEnglish " +
                                 "WHERE ScreenID = '" + myobj.getScreenId() +
                                 "' AND 3270Literal = '" + sLabelString + "';");
//try {
int count = 0;
while (rs.next()) {
      sDefinition = rs.getString("Definition");

      System.out.println(sDefinition);    

}
if (count == 0) {
    System.out.println("No results found");
}

rs.close();
con.close();

//} catch (SQLException e) {
//}


%>

<html>
<title>Whats This</title>
<body>
<p> <%=sDefinition %> </p>
</body>
</html>

CJ
0
 
LVL 6

Accepted Solution

by:
kotan earned 50 total points
ID: 7045945
Check for field names and types in the original database. Make sure all your usages are correct.

What is the type of ScreenID and 3270Literal?
0
 

Author Comment

by:DoughBoy
ID: 7046153
Ah, my friend. Thank you. "3270Literal" was a bad name. It needed a character to start the table name.
Good call.
Thanks to all of you for your help. I learned a lot.
DoughBoy
0

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