Relation visitor fails to visit the `SHOW COLUMNS` statement in the latest commit of the main branch

[goldmedal]

Description

This problem can be reproduced by adding a test case at

datafusion-sqlparser-rs/src/ast/visitor.rs

Lines 736 to 738 in 525d178

	fn test_sql() {
	let tests = vec![
	(

Consider a case

            (
                "SHOW COLUMNS FROM t1",
                vec![
                    "PRE: STATEMENT: SHOW COLUMNS FROM t1",
                    "PRE: RELATION: t1",
                    "POST: RELATION: t1",
                    "POST: STATEMENT: SHOW COLUMNS FROM t1",
                ],
            ),

The test case is passed in the previous release tag v0.52.0-rc3. However, in the latest commit of the main branch 525d178 , the test fails and the result is

     "PRE: STATEMENT: SHOW COLUMNS FROM t1",
     "POST: STATEMENT: SHOW COLUMNS FROM t1",

It may cause the upstream project, DataFusion, to fail to execute the SHOW COLUMNS FROM xxx SQL.
https://github.com/apache/datafusion/blob/18fc103a403ab0efe5245dd4352f3f3b93c2a4fe/datafusion/core/src/execution/session_state.rs#L540

[goldmedal]

I think the reason is we changed the table name to Option<ObjectName> in #1501 but the visitor can only recognize the ObjectName. 🤔

datafusion-sqlparser-rs/src/ast/mod.rs

Lines 7587 to 7590 in 525d178

	pub struct ShowStatementIn {
	pub clause: ShowStatementInClause,
	pub parent_type: Option<ShowStatementInParentType>,
	pub parent_name: Option<ObjectName>,

[alamb]

Thank you for debugging this @goldmedal 🙏

I was wondering why that test was failing on

• WIP: Update sqlparser to next release datafusion#13546

[alamb]

I suspect this was introduced by this PR from @yoavcloud

• Add support for Snowflake SHOW DATABASES/SCHEMAS/TABLES/VIEWS/COLUMNS statements #1501

Any chance you can help us fix it @yoavcloud?

[goldmedal]

Thank you for debugging this @goldmedal 🙏

I was wondering why that test was failing on

• POC: Update to sqlparser with span (source text) location datafusion#13546

I tried to support to visit the option field by #1556

[yoavcloud]

Apologies for the regression here, I'm still learning my way around the project. Looks like @goldmedal has a PR already that addresses this issue.

[alamb]

No problems -- clearly we don't have good test coverage for this either 🤔