serverError:class javax.faces.el.EvaluationException could not execute query - mysql

I am getting this error from host server. I am using mysql database,tomcat and hibernate orm tool.
How can I solve this problem? Can you help me please?

I was having this problem too.
You should take a look if there's object that is not initialized, then you shoul see if the tables are specified correctly (this is more common if you develop in Windows and deploy in Linux or vice-versa).
For mote details take a look here:
Manager Bean do not returns when the project is online

Related

Activiti framework and teradata compatibility

Recently, I started investigation of activiti framework to integrate it into my current project.
In our project we use teradata database.
So I added activiti dependency and created simple bpmn process for testing purposes.
I tested this process with h2 inmemory database and it worked fine.
But when configured project to use teradata I've got exception on spring boot application startup.
Caused by: org.activiti.engine.ActivitiException: couldn't deduct database type from database product name 'Teradata'
I have googled and found only this topic on internet space:
https://hub.alfresco.com/t5/alfresco-process-services/does-activiti-support-teradata-database/m-p/17587#M287
It seems there is no way to integrate activiti and teradata for now.
So the reason why I am here posting this question is that I just want to make sure there is no way to reach integration between those technologies.
Any suggestions and ideas will be welcomed. Thank you.
Activiti is an open source product and can be "adapted" to almost any back end transactional database. Transaction support is a must as any BPMN engine is basically a state machine.
Database access is isolated in the entity layer and specific SQL is managed by the Ibatis ORM.
To integrate a specific database, you will need to modify the entity and ORM layers.
Certainly possible and actually not that much work (typically about 30 hours in my experience), but it is work you have to do and maintain yourself.

Does MVVMCross use tcp to have remote views

I'm new to MVVMCross and I'm trying to see if it does remote views over tcp. From the docs I have read, it looks like the only remote part would be the database (eg MSSQL over TCP) but that seems all wrong.
Does MVVMCross have a communications layer between the ModelView and the Model ? If so, is there any documentation on it. I have looked but have not found any.
What I'm trying to achieve is to have most of the application on one machine and have a thin client (ie the View) able to run remotly. The only information I have found on this is that it seems to be done for mobile devices but I have not been able to find any details on the communications interface.
AFAIK it doesn't. You should communicate with your server through HttpClient or if you want something more real time you can use something like SignalR to get your model and update the Viewmodel which will end up updating the View.
If you want an example of either approaches tell me.
HIH.

Squirrel: UnityJDBC throwing ClassNotFoundException

I've using Squirrel SQL 3.6.
I have working connections to two databases, which I'll call A and B. I can run queries against A and B without issues. They've been setup and working for a couple years.
I'm needing to run queries against both of these datasources/connections and have Squirrel handle the joins between them.
I've got the UnityJDBC driver added. I've created a connection using same. The next step is to add A and B to it, such that I can run queries across them.
I open the connection, right-click and select "(Virtualization) Add Source" and select A from the list, then tell it to "Add." I don't add any other properties.
It tells me:
Preparing to add data source...
ClassNotFoundException for Driver: com.ibm.as400.access.AS400JDBCDriver
Make sure driver is in your classpath.
If that driver wasn't in the classpath, I'm assuming I wouldn't be able to use connection A at all. Which leads me to believe UnityJDBC has another classpath all its own. Any suggestions on what that would be, where to find it, how to fix this, etc?
As said in this instruction http://www.unityjdbc.com/squirrel/MultiSourceVirtualizationPlugin_install.pdf :
Make sure to add other database JDBC jars into the squirrel/lib folder
or JRE classpath. The plugin cannot access drivers in custom
classpaths used by SQuirreL.
Hope it's not too late and helps ;)

Type provider for MySql

I've been searching for an example on how to connect to a MySql database and use F# type providers but I could not find anything online.
Can anyone give me a clue? What - if any - extra packages do I need? Do I use SqlDataConnection or SqlEntityConnection.
Excuse my ignorance but I'm totally lost. Any and all help is appreciated. I love the idea of type providers and have a fair amount of experience with functional programing but it's the setup around this that gets me.
I don't think there is out-of-the box type provider that would work with MySQL at the moment. However, Ross McKinlay has been working on a better type provider for SQL databases (more generally). It currently works with MS SQL server and SQL Lite.
It should be possible to write an extension to support MySQL with fairly small amount of work (but sadly, it has not been done yet). See his blog for details. I'm sure that contributions are welcome!
I haven't tested this, but if Entity Framework works with MySql (it does) and if F# has an Entity Framework Type Provider (it does) then I would expect the Entity Framework Type Provider to work with MySql.
Have you tried that approach?
If you are still interested, I recently added support for MySQL to my SQL type provider, help with testing would be good!
A general SQL database type provider, supporting LINQ queries, schema
exploration, individuals and much more besides.
The provider currently supports MS SQL Server, SQLite, PostgreSQL,
Oracle, MySQL and MS Access. All database vendors except SQL Server
and MS Access will require 3rd party ADO.NET connector objects to
function. These are dynamically loaded at runtime so that the SQL
provider project is not dependent on them. You must supply the
location of the assemblies with the "ResolutionPath" static parameter.
https://fsprojects.github.io/SQLProvider/
I think I actually got it to work!! Here's what I did:
Installed the MySql Connector
Added to and referenced MySql.Data & MySql.Data.Entity in my project
Added and EntityFramework 5.0 to my project
Added both MySql.Data & MySql.Data.Entity to the GAC.
Then I was able to use SqlEntityConnection and get the types!
There's gotta be an easier way to do this though. I particular, adding stuff to the GAC should not be a part of all this process. I mean, am I asking to much for this to work pretty much "out of the box"?!
Unfortunately, I'm extremely unfamiliar with .Net yet, so I couldn't get the whole thing working with the App.config file. Based on my searches here, it looks like I'm not the only one having troubles with this. If anyone has any feedback/suggestions please help!

MySQL User Defined Function to send a windows message

G'Day,
I want to use the Windows API Postmessage() call from inside a MySQL UDF on MySQL 5.1.51 (XP SP3). I know the UDF (Written in Delphi 2006) is working by setting a bogus result for the UDF.
The syntax of the UDF takes two integer params, one for a window handle and the other for a message number. However a call to PostMessage() from inside my UDF causes an exception in mysqld and the service stops.
Any ideas or pointers? Alternatively if anyone can tell me how I am able to simulate IB Events for MySQL via AnyDAC and Delphi OR an alternate approach to getting a notification when a record has changed in the database then please show me the light.
--Donovan
Your going to run into problems with this approach mainly due to the fact that messaging will only work to the same access level, and within the same session on the same computer. You would be better served by using other methods, such as TCPIP sockets, MailSlots, Memory mapped files, ect.
To best simulate a post message, I would use TCPIP UDP. A good lightweight library that I have used in the past is Synapse. The synapse library from SVN does run quite well against the latest versions of Delphi. The class you will want to use for this is the TUDPBlockSocket.
As an alternative to windows messages or TCP/IP, you might want to consider the named pipes answer to this question on sending information between two Delphi programs and this question on what named pipes are.
--jeroen
While I have had success via the UDF / Windows Pipe route I had another idea leveraging off being able to tap into the information message framework(?) in MySQL. See https://stackoverflow.com/q/3992779/223742