How to parse an SQL query into an XML tree?

dawookster has asked for the wisdom of the Perl Monks concerning the following question:

Has anyone seen anything which parses an SQL query (not the output) into an XML tree?

I need to evalaluate parts of the query to decide how to format the output... which would be much easier if the query was in a well formed format like XML.

Edited by Arunbear: Changed title from 'sql2xml ', as per Monastery guidelines

Comment on How to parse an SQL query into an XML tree?

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Re: How to parse an SQL query into an XML tree? by jZed (Prior) on Apr 11, 2005 at 04:22 UTC
SQL::Statement is your friend. For example: `use SQL::Statement my $parser = SQL::Parser->new(); $parser->{PrintError}=0; $parser->{RaiseError}=1; for my $sql(<DATA>) { my $stmt = SQL::Statement->new($sql,$parser); printf "Command %s\n",$stmt->command; printf "Num Pholders %s\n",scalar $stmt->params; printf "Columns %s\n", join',', map{$_->name} $stmt->columns; printf "Tables %s\n",join',',$stmt->tables; printf "Where op %s\n",join',',$stmt->where->op; printf "Order Cols %s\n",join',',map{$_->column}$stmt->order; }` [download] The module will handle implicit and explicit joins, column and table alias, complex nested where clauses, and more. It doesn't yet handle subqueries.	[reply] [d/l]
Re: How to parse an SQL query into an XML tree? by gam3 (Curate) on Apr 11, 2005 at 02:41 UTC
Depending on the complexity of the select statments, and the flavor of SQL you are using I would think that you could write a parser fairly quickly using Parse::Yapp, or simular. The grammer of a simple select statment is: `select_statement: 'SELECT' opt_distinct fields_list 'FROM' tables_list + opt_where opt_orderby opt_groupby ; opt_distinct: 'DISTINCT' \| ; opt_where: 'WHERE' where_list \| ; fields_list: field \| field ',' fields_list ; opt_groupby: 'GROUP BY' fields_list \| ; opt_orderby: 'ORDER BY' order_fields_list \| ; order_fields_list: order_field \| order_field ',' order_fields_list ;` [download] At this point I would say you are done. Writing out the SQL with XML does not get you anything. If the SQL is badly formed then the XML will also be badly formed. You might also look at Parse::RecDescent::Genezzo::Parse::SQL. -- gam3 A picture is worth a thousand words, but takes 200K.	[reply] [d/l]