Please have a look in the SqlDialect class:
/**
* A dialect useful for generating SQL which can be parsed by the
* Calcite parser, in particular quoting literals and identifiers. If you
* want a dialect that knows the full capabilities of the database, create
* one from a connection.
*/
public static final SqlDialect CALCITE =
DatabaseProduct.CALCITE.getDialect();
Just select the suitable Dialect from the DatabaseProduct enum.
Julian
Am 31.10.18, 12:28 schrieb "Shashwat Kumar" <[email protected]>:
Hi Julian,
I have been able to successfully implement your above suggestions and got
properly modifed SqlNode in the end.
Now I want to convert SqlNode to sqlquery which I want to pass to JDBC
connection. Could you please help in that?
sqlNode.toString() is not giving proper query.
sqlNode.toSqlString(SqlDialect dialect) seems to be appropriate solution
but what should I pass as dialect?
On Wed, Oct 31, 2018 at 4:05 PM Julian Feinauer <
[email protected]> wrote:
> Hi Shashwat,
>
> the implementation to use should be SqlBasicCall.
> And to achieve what you want to do I would use
>
> SqlParserPos pos = yourNode.getParserPosition();
> SqlNode aliased = new SqlBasicCall(SqlStdOperatorTable.AS, new
> SqlNode[]{yourNode, new SqlIdentifier(Collections.singletonList("v", pos),
> pos)}
>
> Note, I did not check above lines so perhaps you have to modify it a bit
> or play around, but this should be the general direction, I think.
>
> Julian
>
> Am 31.10.18, 11:28 schrieb "Shashwat Kumar" <[email protected]>:
>
> Hi Julian,
>
> Thank you for quick response.
> SqlCall is abstract class so I am not able to find which concrete
> subclass
> of it I should instantiate. Could you please give some more hint or
> code
> snippet to do it? Also how to modify the identifier name. Say I want
to
> change value to _MAP['value'] e.g.
>
> SELECT _MAP['value'] as v FROM Data
>
> On Wed, Oct 31, 2018 at 3:42 PM Julian Feinauer <
> [email protected]> wrote:
>
> > Hi Shashwat,
> >
> > Calcite does this by a Call to the "AS" Operator (basically value as
> v is
> > just syntactic sugar for AS(value, v)).
> > So you need to create a call node (SqlCall) with the AS Operator
> > (SqlStdOperatorTable.AS) and as operands you node and an
> SqlIdentifier for
> > the Alias.
> >
> > But your visitor should then return SqlNode not String, or?
> >
> I'll will change it to SqlNode.
>
> >
> > Best
> > Julian
> >
> > Am 31.10.18, 11:07 schrieb "Shashwat Kumar" <
> [email protected]>:
> >
> > I want to modify select identifiers in sql statement. For
example
> > SELECT value FROM Data
> > to
> > SELECT value as v FROM Data
> >
> > I am able to get SqlNode for select identifiers as follows.
> >
> > public String visit(SqlCall sqlCall) {
> >
> > SqlNodeList selectList = ((SqlSelect)
> sqlCall).getSelectList();
> > for (SqlNode sqlNode : selectList) {
> > *// do something with sqlNode*
> > }
> >
> > }
> >
> > Now how to change sqlNode as per requirement?
> >
> >
> > --
> > Regards
> > Shashwat Kumar
> >
> >
> >
>
> --
> Regards
> Shashwat Kumar
>
>
>
--
Regards
Shashwat Kumar
