Bug fix: Disable L059 in snowflake dialect (#3260)

* Bug fix: Disable L059 in snowflake dialect

* Add note explaining the rule is disabled for Snowflake

* Update src/sqlfluff/rules/L059.py

Co-authored-by: Danny Jones <51742311+WittierDinosaur@users.noreply.github.com>

Co-authored-by: Barry Hart <barry.hart@mailchimp.com>
Co-authored-by: Danny Jones <51742311+WittierDinosaur@users.noreply.github.com>

src/sqlfluff/core/default_config.cfg

@@ -169,6 +169,7 @@ ignore_words_regex = None
 prefer_quoted_identifiers = False
 ignore_words = None
 ignore_words_regex = None
+force_enable = False
 
 [sqlfluff:rules:L062]
 # Comma separated list of blocked words that should not be used

src/sqlfluff/rules/L059.py

@@ -24,6 +24,13 @@ class Rule_L059(BaseRule):
     When ``prefer_quoted_identifiers = False`` (default behaviour), the quotes are
     unnecessary, except for reserved keywords and special characters in identifiers.
 
+    .. note::
+       This rule is disabled by default for Snowflake because it allows quotes as
+       part of the column name. In other words, ``date`` and ``"date"`` are two
+       different columns.
+
+       It can be enabled with the ``force_enable = True`` flag.
+
     **Anti-pattern**
 
     In this example, a valid unquoted identifier,
@@ -75,7 +82,9 @@ class Rule_L059(BaseRule):
         "prefer_quoted_identifiers",
         "ignore_words",
         "ignore_words_regex",
+        "force_enable",
     ]
+    _dialects_allowing_quotes_in_column_names = ["snowflake"]
 
     # Ignore "password_auth" type to allow quotes around passwords within
     # `CREATE USER` statements in Exasol dialect.
@@ -87,6 +96,17 @@ def _eval(self, context: RuleContext) -> Optional[LintResult]:
         self.prefer_quoted_identifiers: bool
         self.ignore_words: str
         self.ignore_words_regex: str
+        self.force_enable: bool
+        # Some dialects allow quotes as PART OF the column name. In other words,
+        # these are two different columns:
+        # - date
+        # - "date"
+        # For safety, disable this rule by default in those dialects.
+        if (
+            context.dialect.name in self._dialects_allowing_quotes_in_column_names
+            and not self.force_enable
+        ):
+            return LintResult()
 
         # Ignore some segment types
         if context.functional.parent_stack.any(sp.is_type(*self._ignore_types)):

test/fixtures/rules/std_rule_cases/L059.yml

@@ -326,3 +326,34 @@ test_pass_insert_overwrite_directory:
   configs:
     core:
       dialect: sparksql
+
+test_fail_quoted_column_ansi:
+  fail_str: |
+    SELECT d."date"
+    FROM d
+  fix_str: |
+    SELECT d.date
+    FROM d
+
+test_pass_quoted_column_snowflake:
+  # The rule is disabled by default in Snowflake.
+  pass_str: |
+    SELECT d."date"
+    FROM d
+  configs:
+    core:
+      dialect: snowflake
+
+test_fail_quoted_column_snowflake_force_enable:
+  fail_str: |
+    SELECT d."date"
+    FROM d
+  fix_str: |
+    SELECT d.date
+    FROM d
+  configs:
+    core:
+      dialect: snowflake
+    rules:
+      L059:
+        force_enable: true