Snowflake: Add DESC[RIBE] EXTERNAL VOLUME

src/ast/mod.rs

@@ -4772,6 +4772,14 @@ pub enum Statement {
         table_name: ObjectName,
     },
     /// ```sql
+    /// DESC | DESCRIBE { VIEW | DATABASE | SCHEMA | EXTERNAL VOLUME } <name>
+    /// ```
+    /// See [DESCRIBE VIEW](https://docs.snowflake.com/en/sql-reference/sql/desc-view),
+    /// [DESCRIBE DATABASE](https://docs.snowflake.com/en/sql-reference/sql/desc-database),
+    /// [DESCRIBE SCHEMA](https://docs.snowflake.com/en/sql-reference/sql/desc-schema)
+    /// and [DESCRIBE EXTERNAL VOLUME](https://docs.snowflake.com/en/sql-reference/sql/desc-external-volume)
+    DescribeObject(DescribeObject),
+    /// ```sql
     /// [EXPLAIN | DESC | DESCRIBE]  <statement>
     /// ```
     Explain {
@@ -5259,6 +5267,7 @@ impl fmt::Display for Statement {
 
                 write!(f, "{id}")
             }
+            Statement::DescribeObject(s) => write!(f, "{s}"),
             Statement::ExplainTable {
                 describe_alias,
                 hive_format,
@@ -8788,6 +8797,8 @@ pub enum ObjectType {
     User,
     /// A stream.
     Stream,
+    /// A Snowflake external volume.
+    ExternalVolume,
     /// A warehouse.
     Warehouse,
 }
@@ -8809,6 +8820,7 @@ impl fmt::Display for ObjectType {
             ObjectType::Type => "TYPE",
             ObjectType::User => "USER",
             ObjectType::Stream => "STREAM",
+            ObjectType::ExternalVolume => "EXTERNAL VOLUME",
             ObjectType::Warehouse => "WAREHOUSE",
         })
     }
@@ -8986,6 +8998,35 @@ impl fmt::Display for DescribeAlias {
     }
 }
 
+/// ```sql
+/// DESC | DESCRIBE { VIEW | DATABASE | SCHEMA | EXTERNAL VOLUME } <name>
+/// ```
+/// See [DESCRIBE VIEW](https://docs.snowflake.com/en/sql-reference/sql/desc-view),
+/// [DESCRIBE DATABASE](https://docs.snowflake.com/en/sql-reference/sql/desc-database),
+/// [DESCRIBE SCHEMA](https://docs.snowflake.com/en/sql-reference/sql/desc-schema)
+/// and [DESCRIBE EXTERNAL VOLUME](https://docs.snowflake.com/en/sql-reference/sql/desc-external-volume)
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct DescribeObject {
+    /// The keyword used, `DESC` or `DESCRIBE`.
+    pub describe_alias: DescribeAlias,
+    /// The kind of object described: `VIEW`, `DATABASE`, `SCHEMA` or `EXTERNAL VOLUME`.
+    pub object_type: ObjectType,
+    /// Name of the object.
+    pub name: ObjectName,
+}
+
+impl fmt::Display for DescribeObject {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "{} {} {}",
+            self.describe_alias, self.object_type, self.name
+        )
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
@@ -12751,6 +12792,12 @@ impl From<CreateWarehouse> for Statement {
     }
 }
 
+impl From<DescribeObject> for Statement {
+    fn from(d: DescribeObject) -> Self {
+        Self::DescribeObject(d)
+    }
+}
+
 impl From<VacuumStatement> for Statement {
     fn from(v: VacuumStatement) -> Self {
         Self::Vacuum(v)

src/ast/spans.rs

@@ -478,6 +478,7 @@ impl Spanned for Statement {
             Statement::Prepare { .. } => Span::empty(),
             Statement::Kill { .. } => Span::empty(),
             Statement::ExplainTable { .. } => Span::empty(),
+            Statement::DescribeObject(..) => Span::empty(),
             Statement::Explain { .. } => Span::empty(),
             Statement::Savepoint { .. } => Span::empty(),
             Statement::ReleaseSavepoint { .. } => Span::empty(),

src/dialect/generic.rs

@@ -372,4 +372,8 @@ impl Dialect for GenericDialect {
     fn supports_add_column_if_not_exists(&self) -> bool {
         true
     }
+
+    fn supports_describe_object(&self) -> bool {
+        true
+    }
 }

src/dialect/mod.rs

@@ -1192,6 +1192,15 @@ pub trait Dialect: Debug + Any {
         false
     }
 
+    /// Returns true if this dialect supports `DESC | DESCRIBE <object_type> <name>`
+    /// for object types other than `TABLE`, e.g. `DESCRIBE VIEW my_view`,
+    /// `DESCRIBE DATABASE my_db` or `DESCRIBE SCHEMA my_schema`.
+    ///
+    /// See <https://docs.snowflake.com/en/sql-reference/sql/desc>
+    fn supports_describe_object(&self) -> bool {
+        false
+    }
+
     /// Returns true if this dialect allows the `EXTRACT` function to words other than [`Keyword`].
     fn allow_extract_custom(&self) -> bool {
         false

src/dialect/snowflake.rs

@@ -479,6 +479,10 @@ impl Dialect for SnowflakeDialect {
         true
     }
 
+    fn supports_describe_object(&self) -> bool {
+        true
+    }
+
     fn allow_extract_custom(&self) -> bool {
         true
     }

src/parser/mod.rs

@@ -15190,6 +15190,14 @@ impl<'a> Parser<'a> {
                 options,
             }),
             _ => {
+                if describe_alias != DescribeAlias::Explain
+                    && self.dialect.supports_describe_object()
+                {
+                    if let Some(statement) = self.parse_describe_object(describe_alias)? {
+                        return Ok(statement);
+                    }
+                }
+
                 let hive_format =
                     match self.parse_one_of_keywords(&[Keyword::EXTENDED, Keyword::FORMATTED]) {
                         Some(Keyword::EXTENDED) => Some(HiveDescribeFormat::Extended),
@@ -15215,6 +15223,33 @@ impl<'a> Parser<'a> {
         }
     }
 
+    /// Parse `{ VIEW | DATABASE | SCHEMA | EXTERNAL VOLUME } <name>` following `DESC | DESCRIBE`.
+    /// Returns `None` if none of the object type keywords is present.
+    fn parse_describe_object(
+        &mut self,
+        describe_alias: DescribeAlias,
+    ) -> Result<Option<Statement>, ParserError> {
+        let object_type = if self.parse_keywords(&[Keyword::EXTERNAL, Keyword::VOLUME]) {
+            ObjectType::ExternalVolume
+        } else {
+            match self.parse_one_of_keywords(&[Keyword::VIEW, Keyword::DATABASE, Keyword::SCHEMA]) {
+                Some(Keyword::VIEW) => ObjectType::View,
+                Some(Keyword::DATABASE) => ObjectType::Database,
+                Some(Keyword::SCHEMA) => ObjectType::Schema,
+                _ => return Ok(None),
+            }
+        };
+        let name = self.parse_object_name(false)?;
+        Ok(Some(
+            DescribeObject {
+                describe_alias,
+                object_type,
+                name,
+            }
+            .into(),
+        ))
+    }
+
     /// Parse a query expression, i.e. a `SELECT` statement optionally
     /// preceded with some `WITH` CTE declarations and optionally followed
     /// by `ORDER BY`. Unlike some other parse_... methods, this one doesn't

tests/sqlparser_common.rs

@@ -22744,3 +22744,18 @@ fn display_create_procedure_parameter_list_propagates_write_errors() {
     let mut writer = RejectingWriter(" (");
     assert_eq!(write!(writer, "{statement}"), Err(fmt::Error));
 }
+
+#[test]
+fn parse_describe_object() {
+    let dialects = all_dialects_where(|d| d.supports_describe_object());
+    dialects.verified_stmt("DESCRIBE VIEW v");
+    dialects.verified_stmt("DESC VIEW db.s.v");
+    dialects.verified_stmt("DESCRIBE DATABASE d");
+    dialects.verified_stmt("DESC SCHEMA db.s");
+
+    let dialects = all_dialects_where(|d| !d.supports_describe_object());
+    assert!(matches!(
+        dialects.verified_stmt("DESC schema"),
+        Statement::ExplainTable { .. }
+    ));
+}

tests/sqlparser_snowflake.rs

@@ -5042,3 +5042,9 @@ fn test_stage_name_delimiters() {
         ParserError::ParserError("Expected: stage name identifier, found: .".to_string()),
     );
 }
+
+#[test]
+fn parse_describe_external_volume() {
+    snowflake().verified_stmt("DESCRIBE EXTERNAL VOLUME my_vol");
+    snowflake().verified_stmt("DESC EXTERNAL VOLUME my_vol");
+}