feat(snowflake): transpile Snowflake IDENTIFIER function to DuckDB by fivetran-kwoodbeck · Pull Request #7723 · tobymao/sqlglot

fivetran-kwoodbeck · 2026-06-09T18:02:42Z

Snowflake's IDENTIFIER(), which resolves a string to a runtime identifier, previously fell through to exp.Anonymous. This folds it into a typed exp.Identifier node (flagged with identifier_func=True) so the Snowflake generator reconstructs IDENTIFIER('name') and the DuckDB generator emits a native identifier. It includes splitting dot-qualified names like IDENTIFIER('t1.col') into a proper exp.Dot chain.

Non-foldable args like IDENTIFIER($var) remain as exp.Anonymous so they round-trip correctly.

Behavior

Snowflake input	DuckDB output
IDENTIFIER('col')	col
IDENTIFIER('t1.col')	t1.col
IDENTIFIER('"Col"')	"Col"
IDENTIFIER($var)	IDENTIFIER($var)

georgesittas

Hey @fivetran-kwoodbeck, I don't think this is the right approach. We should parse the IDENTIFIER(...) argument, and only when it's a string, otherwise you risk breaking case-sensitive identifiers. I wonder if we should just use to_column and to_table directly and produce semantically equivalent SQL without the IDENTIFIER call.

Falling back to an Anonymous node in other cases is good. I would also have a try-except block to make sure we gracefully handle parse failures and fall back to the IDENTIFIER(...) syntax.

Check this out too: https://github.com/fivetran/sqlglot-integration-tests/pull/452#pullrequestreview-4467142494.

georgesittas · 2026-06-10T10:59:49Z

        any_token: bool = True,
        tokens: Collection[TokenType] | None = None,
    ) -> exp.Expr | None:
        if self._match_text_seq("IDENTIFIER", "("):


How come we need both this and an entry in FUNCTION_PARSERS to handle IDENTIFIER(...)?

_parse_identifier_function is used for calls such as SELECT IDENTIFIER('foo') FROM t whereas _parse_id_var is used for calls such as CREATE TABLE IDENTIFIER('foo')

Did you verify that this is still needed though? If we remove the IDENTIFIER()-related logic from this method, does the parser fail to handle SQL like your example?

georgesittas · 2026-06-15T11:45:59Z



+class DynamicIdentifier(Expression):
+    arg_types = {"this": True}


Suggested change

arg_types = {"this": True}

pass

georgesittas · 2026-06-15T11:46:20Z

        return self.name


+class DynamicIdentifier(Expression):


Suggested change

class DynamicIdentifier(Expression):

# https://docs.snowflake.com/en/sql-reference/identifier-literal

class DynamicIdentifier(Expression):

I'm not sure this should inherit from Expression, but instead from Func. If we do that:

We can do a simple rename_func in Snowflake's generator

We don't need to have an entry in FUNCTION_PARSERS, only map "IDENTIFIER" to it in FUNCTIONS and the rest is taken care of.

Just a couple of simplifications. Since this is really a function, it also aligns better with intuition.

sounds good, will update

georgesittas · 2026-06-15T11:48:43Z

+        if this and this.is_string:
+            return this.name


Don't you still need to parse this when transpiling it? maybe_parse(this.name).sql(self.dialect). Otherwise if you transpile into something like Databricks, for example, you'll emit "-delimited text which is a string literal, not an identifier.

georgesittas · 2026-06-15T11:49:08Z

+        this = expression.this
+        if this and this.is_string:
+            return this.name
+        return self.func("IDENTIFIER", this)


We should call unsupported if control falls to this return statement.

georgesittas · 2026-06-15T12:01:09Z

        any_token: bool = True,
        tokens: Collection[TokenType] | None = None,
    ) -> exp.Expr | None:
        if self._match_text_seq("IDENTIFIER", "("):


Did you verify that this is still needed though? If we remove the IDENTIFIER()-related logic from this method, does the parser fail to handle SQL like your example?

georgesittas · 2026-06-15T12:01:23Z

+    def _fold_identifier_literal(self, arg: exp.Expr | None) -> exp.Expr:
+        return self.expression(exp.DynamicIdentifier(this=arg))


This looks unnecessary, let's inline this where it's needed.

The branch is needed, if we remove it, the following test fails:

CREATE TABLE IDENTIFIER('foo') (COLUMN1 VARCHAR, COLUMN2 VARCHAR)

georgesittas · 2026-06-15T12:01:58Z

        return self.name


+class DynamicIdentifier(Expression):


I'm not sure this should inherit from Expression, but instead from Func. If we do that:

We can do a simple rename_func in Snowflake's generator

We don't need to have an entry in FUNCTION_PARSERS, only map "IDENTIFIER" to it in FUNCTIONS and the rest is taken care of.

Just a couple of simplifications. Since this is really a function, it also aligns better with intuition.

This comment was marked as outdated.

Sign in to view

georgesittas self-assigned this Jun 10, 2026

georgesittas reviewed Jun 10, 2026

View reviewed changes

fivetran-kwoodbeck force-pushed the transpile/snowflake-identifier-function branch from 12b5a1f to d97ad27 Compare June 11, 2026 04:20

georgesittas reviewed Jun 11, 2026

View reviewed changes

Comment thread sqlglot/parsers/snowflake.py Outdated

Comment thread sqlglot/parsers/snowflake.py Outdated

Comment thread sqlglot/parsers/snowflake.py Outdated

Comment thread sqlglot/parsers/snowflake.py Outdated

Comment thread sqlglot/generators/snowflake.py Outdated

fivetran-kwoodbeck force-pushed the transpile/snowflake-identifier-function branch from d97ad27 to 12e2d66 Compare June 12, 2026 18:28

georgesittas reviewed Jun 15, 2026

View reviewed changes

axtio mentioned this pull request Jun 15, 2026

How come we need both this and an entry in FUNCTION_PARSERS to handle IDENTIFIER(...)? #7751

Closed

fivetran-kwoodbeck added 5 commits June 16, 2026 15:15

first version of IDENTIFIER

773318e

removed redundant code

2f73aa4

updates as per PR feedback

8c16243

refactored to DynamicIdentifier approach

97453f5

switched to Func, variety of tweaks

bdeb4b5

fivetran-kwoodbeck force-pushed the transpile/snowflake-identifier-function branch from 12e2d66 to bdeb4b5 Compare June 16, 2026 19:15



		class DynamicIdentifier(Expression):
		arg_types = {"this": True}

	class DynamicIdentifier(Expression):
	# https://docs.snowflake.com/en/sql-reference/identifier-literal
	class DynamicIdentifier(Expression):

		def _fold_identifier_literal(self, arg: exp.Expr \| None) -> exp.Expr:
		return self.expression(exp.DynamicIdentifier(this=arg))

Conversation

fivetran-kwoodbeck commented Jun 9, 2026

Uh oh!

This comment was marked as outdated.

georgesittas left a comment • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

fivetran-kwoodbeck Jun 10, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

georgesittas left a comment •

edited

Loading

fivetran-kwoodbeck Jun 10, 2026 •

edited

Loading