very cool dain very cool marcf
|-----Original Message----- |From: [EMAIL PROTECTED] |[mailto:[EMAIL PROTECTED]]On Behalf Of Dain |Sundstrom |Sent: Tuesday, February 26, 2002 7:10 PM |To: JBoss-dev; JBoss-user |Subject: [JBoss-dev] New EJB-QL compiler (ORDER BY and DynamicQL) | | |The new EJB-QL compiler is finished and checked in tip. The new compiler |is a complete rewrite in JavaCC, and is much faster, easier to maintain, |and has error messages. I was surprised by the number of errors I found |in the old parser. You guys haven't been pushing the engine enough, so |to give you incentive to test the new engine I've added several new |features. | | |Error messages: |This is not really a feature but as we didn't have them before it feels |like a feature. | |JBossQL: |I actually wrote two compilers a spec compliant EJB-QL compiler and |JBossQL compiler. JBossQL is a superset of EJB-QL which adds support for |ORDER BY. To use JBossQL you override ejb-ql declaration in your |jbosscmp-jdbc.xml file with a jboss-ql element (i.e. just copy the query |element from your ejb-jar.xml file, change ejb-ql to jboss-ql and add |the order by clause. The BNF for order by follows: | | JBossQL := select_clause from_clause [where_clause] [order_by_clause] | order_by_clause := ORDER BY order_by_path_expression | ( , order_by_path_expression)* | order_by_path_expression := ( numeric_valued_path | | string_valued_path | | datetime_valued_path ) [ASC | DESC] | | |dynamic-ql: |The new compiler is eye-blink fast, so I added a new query type |dynamic-ql. With dynamic-ql you can generate a JBossQL query and pass it |along with the parameters to the engine to be compiled and execute at |runtime. To use this query you add an ejbSelect method to your bean |with the following signature: | | <return-type> ejbSelect<some-name>(String jbossQL, Object[] args) | |You must declare the query type in your ejb-jar.xml (required by the |spec; just leave the ejb-ql element empty) and in your jbosscmp-jdbc.xml |file override the impl with an empty <dynamic-ql/> element. | | |For more info specifying the queries, see the jbosscmp-jdbc_3_0.dtd | |Please, post follow-ups in the online forum at |http://main.jboss.org/thread.jsp?forum=46&thread=9743 | |-dain | | |_______________________________________________ |Jboss-development mailing list |[EMAIL PROTECTED] |https://lists.sourceforge.net/lists/listinfo/jboss-development _______________________________________________ Jboss-development mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/jboss-development
