Hi.<br><br>I&#39;ve really enjoyed Brent&#39;s Lava parser, and used them (with some modifications) to parse SQL for DB2 for an internal project.&nbsp; I&#39;d like to share some of this work - at least the stuff that should be (fairly) easy to merge into Lava.&nbsp; There is more - but I don&#39;t really know how you&#39;d translate Insert/Update/Delete statements from SQL into Magma.
<br><br>I&#39;ve stripped out most of the stuff that there just isn&#39;t any support for at this time (not to mention it was mostly DB2 specific - maybe the standard, but I&#39;m not sure).&nbsp; I&#39;ve made some changes to the AST, although I can&#39;t claim that all of them will work with Magma (since I haven&#39;t tried any at all).&nbsp; The changes are:
<br><br>Common Table Expressions:<br><br>In the Statement section of the parser, I&#39;ve added a section that deal with WITH clauses.&nbsp; This should have the effect of creating &#39;temporary&#39; tables in the main select (roughly analogous to subQueries), and I think this should just work.&nbsp; Here&#39;s an example of a query using this:
<br><br>with t1 as (select * from me), t2 as (select him from you)<br>SELECT col1, wm.col2 <br>from wamu wm<br>WHERE col1 = &#39;me&#39; AND wm.col2 != col1<br><br>There are several other things you can do with CTE&#39;s (such as recursive queries and putting change statements in them), but I doubt these will work as is - and really aren&#39;t to common.&nbsp; I think they make for nicer organized queries, though.
<br><br>In the columnReference and tableReference I have added a schema attribute and accessors to deal with schemas, like:<br>schema.table.column<br>schema.table<br>I think these might map to Namespaces if those ever make it into Squeak in a consistent manner.&nbsp; Otherwise, they could probably just be ignored in Magma, I guess.
<br><br>In tableReferenceList, I&#39;ve added a joinTableReference clause.&nbsp; This allows for things like:<br>from table1 join table2 on table1.col = table2.col<br>This is the &#39;new&#39; standard for joins (SQL-92) that several database vendors have been pushing.&nbsp; The code to use it in Magma probably isn&#39;t fully thought out - it currently uses a JoinedTableReference class to represent this.&nbsp; Currently this reduces the JoinedTableReference to a LaTableReference, and puts the joinConditions (on clause) in the joinCondition part of the LaSelection.&nbsp; To make it fully useful with minimal work, I think you could move the joinConditions to the whereCondition, and it should just work.
<br><br>In tableAlias, I&#39;ve added a clause where you can just use the an alias without the &quot;as&quot;.&nbsp; This is valid (at least in DB2).<br><br>In predicate, I&#39;ve added an existsPredicate.&nbsp; This causes the subquery to run, and if something is found, then that rows (from the outer query) is returned, else it isn&#39;t.&nbsp; Also, a not exists is present, so:
<br>[not] exists (select 1 from table where name = &#39;me&#39;)<br>This is represented in the AST, but I have no idea or suggestions at this time as to how this should work with Magma.<br><br>Finally, in literal, I&#39;ve added a &quot;null&quot; string, which should probably equate to nil internally.&nbsp; Or at least I think I did - it looks like it is already in version .36, so maybe that was already there.&nbsp; Oh well.
<br><br>Oh, and I also added a lot of #qualifier messages to several of the AST classes - that was so I could analyze the parsed results for my purposes, and I just left them in.<br><br>Here&#39;s my Parser definition (based off of your Monticello version 31) and a change set containing the AST changes.
<br><br>Thanks,<br><span class="sg">Chris Cunningham<br>
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