[antlr-interest] Newbie needs guidance on parsing SQL

[Michiel Vermandel]

Hi,

I have written a Forms, Sql and Plsql Parser.

I solved the problem in the following way:

(Lets see to an Insert statement)

insert into my_table (...)
values(...)
;


In my sql.g I have the following:

insert_command: 
        "insert" "into" selected_table 
        column_list
        ( ( "values" OPEN_PAREN! plsql_exp_list CLOSE_PAREN! ) 
        | select_statement ) 
   { ## = #([INSERT_STATEMENT, "insert_statement"], ##); }
        ;

with  selected_table:

selected_table:
        ( table_spec | subquery ) ( table_alias )?
        ;

table_spec:
        ( schema_name DOT )? table_reference ( AT_SIGN link_name )?
        ;

table_reference: 
        object_name 
   { ## = #([TABLE_REF, "ref_table"], ##); }
        ; 

object_name:
   ( identifier ( DOT (object_dot_name) )?
   )
   { #object_name = #([OBJECT_NAME, "<#OBJECT_NAME#>"], #object_name); };

In this way I get in my AST something like

INSERT_STATEMENT
        TABLE_REF
                OBJECT_NAME
                        "my_table"

I walk the AST tree (own code) and whenever I get a TABLE_REF node I 
expect it to have a child node OBJECT_NAME which must have a child node on 
its own which contains the table name.

For every TABLE_REF I create a custom made SqlTable object and add it to a 
list of references. 
Then in a second face I try to resolve all objects in my references list 
by looking them up in a repository...







Terence Parr <parrt at cs.usfca.edu> 
Sent by: antlr-interest-bounces at antlr.org
20/09/2006 20:16

To
Antlr List <antlr-interest at antlr.org>
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Subject
Re: [antlr-interest] Newbie needs guidance on parsing SQL







On Sep 20, 2006, at 9:53 AM, WALTERS, CRAIG P [AG/1000] wrote:

>
> I am doing my 1st antlr project (version 2.7.6).  I downloaded 
> DmlSQL2/SQL2
> and converted them from C++ to Java.  What I need to do is scan a 
> string
> containing (Oracle) SQL DML and extract all of the names of the 
> tables that
> are the targets of modifications (INSERT, UPDATE, DELETE, 
> TRUNCATE).  I
> can't figure out how to get the table names.  Can someone give me some
> suggestions?

Hi. Write the grammar for the subset and then put in an action that 
references the IDENTIFIER matched for table name.  Use the text for 
that ID as you wish.

Ter


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