Overly Persistent Database Connections

When we "disconnect" a connection, is it truly gone?
Because I'm thinking it may not be really gone until we leave sql developer.

Finally had a chance to properly test this.
The connections do appear to be removed upon disconnecting.
However, I experienced a number of "false disconnects".
By that, I mean, I told sql developer to disconnect from a connection, saw no warning/error message saying it did not disconnect, but the disconnect did not take place. The connection remained in effect and the connection list in the tree continued to show it as connected.
On several occasions, I told it to connect but it did not. Ditto for lack of warning/error message and for the connection tree showing it as disconnected.

Similar Messages

Servlets and Persistent Database Connections

I'm looking at building an application using
java Servlets.
My Application will consist of many individual Java Servlets.
I want to ensure that there is a persistent database connection so that the users do not have to log on again when a page generated via Servlet1 contains a URL to Servlet2....
null

Look at the Http session class in the Servlet specification. It will maintain state for you across client requests.

Persist Database connection over user's session

On portal 3.0.9 with JPDK v1 I have a web provider that has a jsp portlet. The portlet has multiple pages which are navigated useing a parameter specified with the pageParameterName tag in the provider.xml. Each page needs to be able to access the database and to allow a rollback for all a users actions until a certain page is visited I need a way for all the access to be done through one database connection.
Putting the dbOpen tag in the event:session_OnStart tag of my globals.jsa file doesn't work (I'm not sure the event:session_OnStart is even executed) and trying to create the connection once with the scope="session" creates an error. Any help would be appreciated.

Generally speaking, persisting a connection over a users session is a BAD idea. If you really need to do it you simply be able to add the Connection object to the session. However, I would strongly recommend that you review your model because it will not scale.

Keeping Database-Connection over several JSPs

Hi all,
when creating a database-connection (Oracle 8.x) with JDBC 2, Tomcat Engine, I encountered the problem, that the connection has been lost after forwarding to another JSP.
What I read from some other forums, there seem to be 2 major ways of how to keep the connection:
- session vars
- connection pool
I feel for our project session will be a approbiate solution, so can you tell me more about it (technical implementation)???
Thanks & Rgds.,
Rainer

you have to declare a bean variable with session scope, like this:
jsp:useBean     id="object-name"
     scope="session"
     type="type-of-object"
     class="fully-qualified-classname"
     beanName="fully-qualified-beanName"
/>
for more infos see (for example) http://www.stardeveloper.com/articles/display.html?article=2001072001&page=1

"Error establishing a database connection" after scale database

Hello, i have a wordpress website hosted at my azure account (www.timothy-k.com). I was trying to scale my sql database and i have changed it from standard to basic. Then, I cant connect to my site, because i have this error.
I scale the database again from basic to standard but the issue persists.
In the website dashboard I can see an another mysql db as a linked resource.I check the credentials for wp-config and they are ok.
Can you help me?

Hi DigitalJo,
Are you moving between the service tiers using the Azure Management Portal? Can we have the error which you get?
Connections to the database may be temporarily dropped when a performance level change or upgrade/downgrade completes, and a few seconds may elapse before connections can be re-established. SQL Database applications should be coded to be resilient to dropped
connections as this can occur anytime in SQL Database when a computer fails in the data center and the SQL Database service fails over the database.
Reference :
https://msdn.microsoft.com/en-us/library/azure/dn369872.aspx
Regards,
Mekh.

OJMS Database Connection Leak

We have configured OJMS for JMS persistence in our application, what we have noticed is that application server seems to open 1 database connection for every new JMS connection. But if the JMS connection is closed the database connections seems to be alive. We are facing some random patterns regarding the connections being open, over a period of time the application seems to run out of database connections since all the connections are being acquired by OJMS.
This is really urgent we are in the post-production phase and this problem is hindering the go-live phase.

rakeshk wrote:
Hi Pointer,
Thank you for the reply, we are using 10.1.3 version of application server. We have tested this both on Windows & Unix flavours and getting the same result. As suggested in the documentation we have configured the datasource connection pool accordingly but no result at all.
We have around 20 threads running in the application and each thread acquires a independent JMS connection, what we have noticed is that for every thread in the application App Server is acquiring 2 database connection 1 for the JMS connection and the other for the JMS Destination. So whats happening is the moment the application is deployed and the threads are started we noticed around 40 connection being taken by OJMS. For the connection factory we have configured private connection pool. I dont know where we are going wrong.
-rakeshHi Rakesh,
I believe you may need to look into your application code and check how many connetions are been opened when a single user logins in to your application.Normally this behaviour is managed by OAS when you set Initial/Min cache parameter;however as a workaround try setting DB profile on the database inorder not to overflow the jdbc connections and from application prespective redcue the initial/min cache parameters and increase the Max connections, in addition set a lower inactivity timeout after monitoring the behaviour and response time of your application pages.
If you problem still persists , i would recommend to log on an SR with oracle support.
HTH !!
Regards,
~Pointer

Why do I get a class conflict between the Prepare SQL.vi and the Get Column Name.vi with the SQL Toolkit compatibility vis from the Database Connectivity Toolkit?

I have done extensive programming with the SQL Toolkit with LabVIEW versions through 6.1. My customer now wants to upgrade to Windows 7, so I am trying to upgrade to LabVIEW 2009 (my latest purchased version) using the Database Connectivity Toolkit, and the SQL Toolkit Compatibility vis. Everything seemed to be going okay with the higher level SQL operations, but I ran into trouble with the Get Column Name.vi.
The pictures below show the problem. The original SQL Toolkit connected the Prepare SQL.vi with the Get Column Name.vi with a cluster of two references, one for connection, and one for sql. The new compatibility vis have a class conflict in the wire because the Prepare SQL.vi contains a cluster with connection, and command references, but the Get Column Name.vi expects a cluster with connection and recordset references.
How do I resolve this conflict?
Thank You.
Dan

I've never worked with the old version of the toolkit, so I don't know how it did things, but looking inside the SQL prep VI, it only generates a command, and the the column name VI wants a recordset. I'm not super familiar with all the internals of ADO, but my understanding is that is standard - you only have the columns after you execute the command and get the recordset back. What you can apparently do here is insert the Execute Prepared SQL VI in the middle and that will return what you need.
I'm not sure why it worked before. Maybe the execute was hidden inside the prep VI or maybe you can get the column names out of the command object before execution. In general, I would recommend considering switching to the newer VIs.
Try to take over the world!

Crystal Report Viewer Not Releasing Oracle Database Connections

I have a very simple vb.net 3.5 web application that uses the Crystal Report viewer 2008 to open a report. My requirements are as follows:
1. Reports are built by another company and provided to us and used in a web environment
2. All reports contain parameter fields
3. The web application must be generic enough that a report can be added to a list and the user simply selects the report and provides database login information. The Crystal report viewer with handle the request for parameter values and prompt the user for their values.
4. All reports connect to an Oracle 10g server.
The above requirements have been meet and we have an extremely simple web application that runs the reports. It is working very well other than the crystal report viewer is not releasing the database connections. This is bad because the credentials are on a per user basis and that same user must login to a different oracle application simultaneously. They are being denied access because the credentials are already in use. We do not have control nor influence over the policies in use on the Oracle server. Ideally we would like to control the Crystal Report viewer so that it closes connections after use.
The web application code is:
Private Sub viewReports_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
If Not IsPostBack Then
ConfigureCrystalReport()
End If
End Sub
Private Sub ConfigureCrystalReport()
'Load the Crystal Report viewer with a report.
Try
Dim reportPath As String = Server.MapPath(Session("reportname"))
crViewer.ReportSource = reportPath
Catch ex As Exception
Response.Write(Server.MapPath(Session("reportname")) & "
" & ex.Message.ToString & "
" & ex.StackTrace.ToString)
End Try
End Sub
Can anyone shed some light on this topic? Thank you

Hello, Timothy;
By default, having the report in session will hold it open for 20 minutes.
If you create the report as a ReportDocument object you can take it out of session and release it more efficiently. That will release the connection.
    Private Sub ConfigureCrystalReports()
        If (Session("hierarchicalGroupingReport") Is Nothing) Then
            hierarchicalGroupingReport = New ReportDocument()
            hierarchicalGroupingReport.Load(Server.MapPath("Hierarchical Grouping.rpt"))
            Session("hierarchicalGroupingReport") = hierarchicalGroupingReport
        Else
            hierarchicalGroupingReport = CType(Session("hierarchicalGroupingReport"), ReportDocument)
        End If
        myCrystalReportViewer.ReportSource = hierarchicalGroupingReport
    End Sub
In the Form Unload of the Viewer:
            'Take the report out of session
            Session("hierarchicalGroupingReport") = Nothing
            Session.Contents.Remove("hierarchicalGroupingReport")
            'Clean up the ReportDocument object
            hierarchicalGroupingReport.Close
            hierarchicalGroupingReport.Dispose()
            hierarchicalGroupingReport = Nothing
            GC.Collect()
Elaine

Issue in creating Database Connection to HFM Applicaion through workspace

Hi,
This is a fresh installation. We are trying to create a new database connection in workspace for HFM Application.
When i click on the Application selection icon, it gives me the below error message,
*"Error connecting to database connection nasbyphyp03: Error: Error getting CSS support information for driver* HsvAdmDriver*".*
I tried re-installing the HsvAdmDriver, but still the problem persists. (nasbyphyp03 is the server name)
But, i am able to access HFM Application from workspace and smartview.
Please advice.
Thanks,
Siva

Can anyone suggest me the solution ???
We are struck with this and unable to process any Reports
Thanks,
Siva

Issue in creating Database Connection to HFM Application through workspace

Hi,
This is a fresh installation. We are trying to create a new database connection in workspace for HFM Application.
When i click on the Application selection icon, it gives me the below error message,
*"Error connecting to database connection nasbyphyp03: Error: Error getting CSS support information for driver* HsvAdmDriver*".*
I tried re-installing the HsvAdmDriver, but still the problem persists. (nasbyphyp03 is the server name)
But, i am able to access HFM Application from workspace and smartview.
Please advice.
Thanks,
Siva

Can anyone suggest me the solution ???
We are struck with this and unable to process any Reports
Thanks,
Siva

Tomcat JDBC Realm Database Connection Error

Hello all,
I am trying to edit the server.xml file on Tomcat so I can use the JDBC Realm instead of the MemoryRealm. Hence, I will be able to read users, passwords and roles from a relational database instead of from the tomcat-users.xml.
I have tried following all the guides on the net I can find, my server.xml looks as follows (after making changes to allow it to use JDBC realm). The only problem is, when I try to run the application the server outputs the following: (after all of these errors have been kicked up a pop-up box then appears titled "Tomcat Manager Application", it asks for a User Name and Password. I have tried the standard user name of "ide" and the password next to it in tomcat-users.xml but it won't accept it. (I am using the netbeans IDE)).
Please could someone suggest any ideas of how I can get the server.xml to work with JDBC realm?
Using CATALINA_BASE:   C:\Documents and Settings\Administrator\.netbeans\5.0beta\jakarta-tomcat-5.5.7_base
Using CATALINA_HOME:   C:\Program Files\netbeans-5.0beta\enterprise2\jakarta-tomcat-5.5.7
Using CATALINA_TMPDIR: C:\Documents and Settings\Administrator\.netbeans\5.0beta\jakarta-tomcat-5.5.7_base\temp
Using JAVA_HOME:       C:\j2sdk1.4.2_08
Created MBeanServer with ID: 1f934ad:107444b1d2b:-8000:ravinder-rdnzoa:1
31-Oct-2005 01:29:33 org.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 on http-8084
31-Oct-2005 01:29:34 org.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 on http-8443
31-Oct-2005 01:29:34 org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 2174 ms
31-Oct-2005 01:29:34 org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
31-Oct-2005 01:29:34 org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/5.5.7
31-Oct-2005 01:29:34 org.apache.catalina.realm.JDBCRealm start
SEVERE: Exception opening database connection
java.sql.SQLException: org.gjt.mm.mysql.Driver
        at org.apache.catalina.realm.JDBCRealm.open(JDBCRealm.java:646)
        at org.apache.catalina.realm.JDBCRealm.start(JDBCRealm.java:720)
        at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1003)
        at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:440)
        at org.apache.catalina.core.StandardService.start(StandardService.java:450)
        at org.apache.catalina.core.StandardServer.start(StandardServer.java:683)
        at org.apache.catalina.startup.Catalina.start(Catalina.java:537)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:324)
        at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:271)
        at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:409)
31-Oct-2005 01:29:34 org.apache.catalina.core.StandardHost start
INFO: XML validation disabled
31-Oct-2005 01:29:36 org.apache.catalina.startup.ContextConfig validateSecurityRoles
INFO: WARNING: Security role name IBM used in an <auth-constraint> without being defined in a <security-role>
31-Oct-2005 01:29:36 org.apache.catalina.startup.ContextConfig validateSecurityRoles
INFO: WARNING: Security role name Auditor used in an <auth-constraint> without being defined in a <security-role>
31-Oct-2005 01:29:37 org.apache.struts.tiles.TilesPlugin initDefinitionsFactory
INFO: Tiles definition factory loaded for module ''.
31-Oct-2005 01:29:37 org.apache.struts.validator.ValidatorPlugIn initResources
INFO: Loading validation rules file from '/WEB-INF/validator-rules.xml'
31-Oct-2005 01:29:37 org.apache.struts.validator.ValidatorPlugIn initResources
INFO: Loading validation rules file from '/WEB-INF/validation.xml'
31-Oct-2005 01:29:38 org.apache.catalina.startup.ContextConfig validateSecurityRoles
INFO: WARNING: Security role name IBM used in an <auth-constraint> without being defined in a <security-role>
31-Oct-2005 01:29:38 org.apache.struts.tiles.TilesPlugin initDefinitionsFactory
INFO: Tiles definition factory loaded for module ''.
31-Oct-2005 01:29:38 org.apache.struts.validator.ValidatorPlugIn initResources
INFO: Loading validation rules file from '/WEB-INF/validator-rules.xml'
31-Oct-2005 01:29:38 org.apache.struts.validator.ValidatorPlugIn initResources
INFO: Loading validation rules file from '/WEB-INF/validation.xml'
31-Oct-2005 01:29:39 org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-8084
31-Oct-2005 01:29:39 org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-8443
31-Oct-2005 01:29:40 org.apache.jk.common.ChannelSocket init
INFO: JK2: ajp13 listening on /0.0.0.0:8009
31-Oct-2005 01:29:40 org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/60 config=null
31-Oct-2005 01:29:40 org.apache.catalina.storeconfig.StoreLoader load
INFO: Find registry server-registry.xml at classpath resource
31-Oct-2005 01:29:40 org.apache.catalina.startup.Catalina start
INFO: Server startup in 5738 ms
31-Oct-2005 01:29:40 org.apache.catalina.realm.JDBCRealm authenticate
SEVERE: Exception performing authentication
java.sql.SQLException: org.gjt.mm.mysql.Driver
        at org.apache.catalina.realm.JDBCRealm.open(JDBCRealm.java:646)
        at org.apache.catalina.realm.JDBCRealm.authenticate(JDBCRealm.java:344)
        at org.apache.catalina.authenticator.BasicAuthenticator.authenticate(BasicAuthenticator.java:181)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:446)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:825)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:738)
        at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:526)
        at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
        at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
        at java.lang.Thread.run(Thread.java:534)
31-Oct-2005 01:29:40 org.apache.catalina.realm.JDBCRealm authenticate
SEVERE: Exception performing authentication
java.sql.SQLException: org.gjt.mm.mysql.Driver
        at org.apache.catalina.realm.JDBCRealm.open(JDBCRealm.java:646)
        at org.apache.catalina.realm.JDBCRealm.authenticate(JDBCRealm.java:344)
        at org.apache.catalina.authenticator.BasicAuthenticator.authenticate(BasicAuthenticator.java:181)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:446)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:825)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:738)
        at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:526)
        at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
        at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
        at java.lang.Thread.run(Thread.java:534)The server.xml looks as follows:
<?xml version="1.0" encoding="UTF-8"?>



<Server port="8025" shutdown="SHUTDOWN">
    
    <Listener className="org.apache.catalina.mbeans.ServerLifecycleListener"/>
    <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener"/>
    <Listener className="org.apache.catalina.storeconfig.StoreConfigLifecycleListener"/>
    
    <GlobalNamingResources>
        
        <Environment name="simpleValue" type="java.lang.Integer" value="30"/>
        
   
    </GlobalNamingResources>
    
    
    <Service name="Catalina">
        
        
        <Connector port="8084" maxThreads="150" minSpareThreads="25" maxSpareThreads="75" enableLookups="false" redirectPort="8443" acceptCount="100" connectionTimeout="20000" disableUploadTimeout="true" URIEncoding="utf-8"/>
        
        
        
        <Connector port="8443"
        maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
        enableLookups="false" disableUploadTimeout="true"
        acceptCount="100" scheme="https" secure="true"
        clientAuth="false" sslProtocol="TLS" />
        
        <Connector port="8009" enableLookups="false" redirectPort="8443" protocol="AJP/1.3"/>
        
        
        
        
        
        
        <Engine name="Catalina" defaultHost="localhost">
            
            
            
            
            
            
            
            
            <Realm className="org.apache.catalina.realm.JDBCRealm"
            driverName="org.gjt.mm.mysql.Driver"
            connectionURL="jdbc:mysql://localhost:3306/tomcatusers"
            connectionName="root" connectionPassword="sikhism1"
            userTable="users" userNameCol="user_name" userCredCol="user_pass"
            userRoleTable="user_roles" roleNameCol="role_name" />
            
            
            
            <Host name="localhost" appBase="webapps" unpackWARs="true" autoDeploy="false" xmlValidation="false" xmlNamespaceAware="false">
                
                
                
                
                
                
                
                
                
                
                
            </Host>
        </Engine>
    </Service>
</Server>Many thanks, and apologies for "dumping" all of the code here.

So looking through the java api docs, I found that the tcUtilJDBCOperations has a connect string for the database. Below is the info it outlines. The questions I have it this. How do you specify the psdriver and URL along with do I need to do this as a persistent instance then add my selectstatement as a part of this or can I just specify this and the select statement will use this connection? Any help you can give would be appreciated.
tcUtilJDBCOperations
public tcUtilJDBCOperations(java.lang.String psDriver,
java.lang.String psUrl,
java.lang.String psUsername,
java.lang.String psPassword)Contructor that sets the parameters for connecting to a database
Parameters:
psDriver - The class name of the jdbc driver
psUrl - The URL of the database
psUsername - The username required to access the database
psPassword - The password for the above username
Nick

Can i use single database connection in a hole java application?

can i use single database connection in a hole java application?.I have so many forms to use database connection.

Theoretically you can. Not only theoretically. I've seen lots of application which only uses one database connection (they were using, oracle or mysql)
The first reply given here assumed that the answer to
your question depends only on the design of your
application. That is not true.Yes it's true. Nothing in the original questions says that you aren't allowed to open or close the single connection that you have. It's looks more like the OP is interested in sharing a connection (i.e having a singleton or a connection pool with only one connection)
It does also depend on the behaviour of the database
in the background.
Most databases have a time out for connections that
are idle Not a problem. Most implementations of connection pools and applications which keeps a connection open have a timer which calls e.g. select * from dual (if you are using oracle) when the connection has been idle for X minutes.
(some, like db2 on z/OS, even cancel
connections, that are not idle, if they are open a
certain amount of time or have reached a given limit
of cpu seconds.)You would also have that problem if you had a connection pool with several connections.
In essence: If you have no control over the time
your application runs (and therefore your connection
is open) or over type or the configuration of the
database you are accessing, you can't do it.See above.
The closest thing to what you want would be using
PooledConnections, iif those are supported for the
database you want to access.Not true.
Kaj

JCAP512 and JCAP6 conflict with concurrent database connectivity

So here is the situation:
Environment:
- We have a production JCAP6 appserver (AIX server 1) running a project pulling data from database A
- We have 4 JCAP512 domains on AIX Servers 2,3,4 running 4 distinct projects pulling data from server A
- All project run on a schedule of 5 minutes and login to the server with the same login
- Database A is SQL Server
- repository based code
Scenario:
- All 5 above processes run concurrently in the greater JCAPS environment.
- When all 5 processes are running, the JCAP6 process runs fine with no issue but at the same time the 4 JCAP512 processes hang on the database side waiting for a resultset with a wait status of ASYNC_NETWORK_IO
- As soon as the JCAP6 process completes, all 4 JCAP512 processes start running with no errors. Once the JCAP6 process starts again, same result.
- We shut off the JCAP6 process and all 4 JCAP512 processes run with no issue
So after my high-school proof setup above my question comes to what is going on??? All of these processes run on their own isolated physical and application servers. Their only commonaliy is the login to the database. Are there any known database connectivity settings that would limit user transactions if another (same) user connection currently exists?
Has anybody seen anything like this? Ay assistance would be greatly appreciated.
Bryan
Edited by: bgrant88 on Jan 29, 2010 2:15 PM

I've never worked with the old version of the toolkit, so I don't know how it did things, but looking inside the SQL prep VI, it only generates a command, and the the column name VI wants a recordset. I'm not super familiar with all the internals of ADO, but my understanding is that is standard - you only have the columns after you execute the command and get the recordset back. What you can apparently do here is insert the Execute Prepared SQL VI in the middle and that will return what you need.
I'm not sure why it worked before. Maybe the execute was hidden inside the prep VI or maybe you can get the column names out of the command object before execution. In general, I would recommend considering switching to the newer VIs.
Try to take over the world!

Export to PDF from populated c# Dataset without Database connection

I have Crystal Reports Developer Full version 11.5.12.1838, all versions of Visual Studio and about 100+ reports targeting printed paper.
They were developed over the last decade with the Developer Designer (and it's predecessors) and are based on SQL Server Stored Procedures. In the past, they were produced at runtime using a MS Access VBA application that either printed them or exported them to PDF files. I have successfully converted that application to C#, however a few problems: despite loading a populated dataset and setting all parameters, the runtime still wants to refresh the dataset. That works for 95% of all reports, but some just use null values for the parameters (despite having set them correctly), others mix the sequence of the parameters (despite querying them correctly) and some don't use the provided credentials. But that is not the main problem.
Now I need a way to produce (export to PDF) these reports at runtime based on a populated C# Dataset without database connectivity for the Crystal environment. The structure of the data in the Dataset is identical to what the stored procedure return in the development environment.
The question is: is that possible and what do I need in terms of version, SDK etc. Any advice (sample links) would be much appreciated.

Hi Ludek;
Thanks for the hints. After many many hours of research and trial and error here are my findings:
Assigning a dataset to CR does NOT work - seems CR is just ignoring it completely. What does (partially) work is assigning a DataTable, however, if you try to do that with a main report and more than ONE sub-report, it fails with likely unrelated error messages (not yet implemented).
I took one of my reports and deleted all sub-reports. Assigned a DataTable at runtime - works fine. Added one sub-report that has a single field (picture) and loaded at runtime with a DataTable. No problem.
Removed that subreport and added another subreport that has a single text field. All good.
Now: having both sub-reports and having both subreports loaded from a DataTable fails. It works if one of the datasets is empty. It also works with 2 sub-reports returning text into their single field.
The DataTables are populated from the exact same stored procedures (and data source) that are embedded in the report from the design (CR XI) - essentially this should be a swap from internal to external fetch with no consequences.
I tried assigning using subDocument.SetDataSource and subDocument.Databas.Tables[0].SetDataSource - no difference.
The background of this: all my reports work just fine using VBA (Access), but that app will be retired and replaced by something C# based. In the meantime, the same report file has to work with both engines.
If I cannot get the DataTable assignment for sub-reports to work, there is a plan-b type possibility: replacing the stored procedure for some sub-reports at runtime - which works using SubReport.Database.Tables[0].Location.= "newSPName" as long as the new sp has no parameters like the old one.
The problem is that the new procedure has 2 parameters and I did not find a way to add them to the parameters collection (not allowed in sub-reports)
Anything that comes to your mind ?
Any help will be much appreciated
Thanks
Rolf

Database Connection Error 42000:[Microsoft][ODBC driver for oracle] Syntax

Hi,
This is Sathish, I am trying to create a report and retrieve data through stored procedure using ODBC Connection. When connecting to the Stored Procedure it is showing Database Connection Error 42000:[Microsoft][ODBC driver for oracle] Syntax error or access violation' Error.
CRXI R2, Oracle 9i.
What do i do to solve this issue.
Regards,
Sathish

Hi Satish
It could be an issue with the driver.
You can try with the OLEDB n Oracle native connection to test if the issue persists.
Also you can refer to the [Troubleshooting Database Connectivity for Crystal Reports|http://www.sdn.sap.com/irj/boc/index?rid=/library/uuid/d05b3bb7-0f28-2c10-4ea3-84dbdc4e414e&overridelayout=true]
Hope this helps!!
Regards
Sourashree

Overly Persistent Database Connections

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