Hi, After few days of struggling on Drools Ruleflow persistence setup on MySQL I finally came to the point when I feel it almost works but I am getting an MySQL error. I see the following SQL query in the log /it does not look correct/ which is followed by the MySQL error message. select processins0_.InstanceId as col_0_0_ from ProcessInstanceInfo processins0_, EventTypes eventtypes1_ where processins0_.InstanceId=eventtypes1_.InstanceId and (? in (.)) WARN [JDBCExceptionReporter] SQL Error: 1064, SQLState: 42000 ERROR [JDBCExceptionReporter] You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '))' at line 1 I googled for similar symptoms but with no success. Will be very grateful for any support, hint, etc! My setup is: JBoss 4.2.3.GA Hibernate 3.2.4.sp1 JBoss Seam 2.2.0.GA Drools 5.1.1 MySQL 5.1.41 / mysql-connector 5.0.7 persistence.xml ... <persistence-unit name="org.drools.persistence.jpa" transaction-type="JTA"> <provider>org.hibernate.ejb.HibernatePersistence</provider> <jta-data-source>java:/edento-MySQL-ds-XA</jta-data-source> <mapping-file>META-INF/orm.xml</mapping-file> <class>org.drools.persistence.session.SessionInfo</class> <class>org.drools.persistence.processinstance.ProcessInstanceInfo</class> <class>org.drools.persistence.processinstance.WorkItemInfo</class> <class>org.drools.persistence.processinstance.variabletypes.VariableInstanceInfo</class> <class>org.drools.persistence.processinstance.variabletypes.JPAPersistedVariable</class> <class>org.drools.persistence.processinstance.variabletypes.SerializablePersistedVariable</class> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect"/> <property name="hibernate.max_fetch_depth" value="3"/> <property name="hibernate.hbm2ddl.auto" value="update"/> <property name="hibernate.show_sql" value="true"/> <property name="hibernate.transaction.manager_lookup_class" value="org.hibernate.transaction.JBossTransactionManagerLookup"/> </properties> </persistence-unit> ... datasources-ds.xml … <xa-datasource> <jndi-name>MySQL-ds-XA</jndi-name> <xa-datasource-property name="URL">jdbc:mysql://localhost:3306/db</xa-datasource-property> <xa-datasource-class>com.mysql.jdbc.jdbc2.optional.MysqlXADataSource</xa-datasource-class> <user-name>root</user-name> <password></password> <track-connection-by-tx>true</track-connection-by-tx> <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.MySQLExceptionSorter</exception-sorter-class-name> <min-pool-size>1</min-pool-size> <max-pool-size>10</max-pool-size> <idle-timeout-minutes>10</idle-timeout-minutes> <metadata> <type-mapping>mySQL</type-mapping> </metadata> </xa-datasource> ... orm.xml <?xml version="1.0" encoding="UTF-8"?> <entity-mappings xmlns="http://java.sun.com/xml/ns/persistence/orm" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm orm_1_0.xsd" version="1.0"> <named-query name="ProcessInstancesWaitingForEvent"> <query> select processInstanceInfo.processInstanceId from ProcessInstanceInfo processInstanceInfo where :type in (processInstanceInfo.eventTypes) </query> </named-query> </entity-mappings> The bean java code – just starts the process and then immediately attempts to load it from the database. EntityManagerFactory emf = Persistence.createEntityManagerFactory("org.drools.persistence.jpa"); Environment env = KnowledgeBaseFactory.newEnvironment(); env.set(EnvironmentName.ENTITY_MANAGER_FACTORY, emf); env.set(EnvironmentName.GLOBALS, new MapGlobalResolver()); StatefulKnowledgeSession ksession = JPAKnowledgeService.newStatefulKnowledgeSession(kbase, null, env); WorkflowProcessInstance processInstance = (WorkflowProcessInstance)ksession.startProcess("TestProcess"); //retrieving... ksession = JPAKnowledgeService.loadStatefulKnowledgeSession(ksession.getId(), kbase, null, env); processInstance = (WorkflowProcessInstance)ksession.getProcessInstance(processInstance.getId()); -- View this message in context: http://drools.46999.n3.nabble.com/Drools-Ruleflow-persistence-on-MySQL-in... Sent from the Drools: User forum mailing list archive at Nabble.com.