Snowflake: Support named file format lifecycle syntax

src/ast/helpers/stmt_data_loading.rs

@@ -85,6 +85,26 @@ pub enum AlterStageOperation {
     },
 }
 
+/// An operation supported by Snowflake's `ALTER FILE FORMAT` statement.
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum AlterFileFormatOperation {
+    /// Rename a named file format.
+    RenameTo {
+        /// New file format name.
+        #[cfg_attr(feature = "visitor", visit(with = "visit_relation"))]
+        new_name: ObjectName,
+    },
+    /// Set one or more format-specific properties or the comment.
+    Set {
+        /// Format-specific options.
+        options: KeyValueOptions,
+        /// Optional comment replacement.
+        comment: Option<String>,
+    },
+}
+
 /// This enum enables support for both standard SQL select item expressions
 /// and Snowflake-specific ones for data loading.
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]

src/ast/mod.rs

@@ -26,7 +26,9 @@ use alloc::{
 };
 use helpers::{
     attached_token::AttachedToken,
-    stmt_data_loading::{AlterStageOperation, FileStagingCommand, StageLoadSelectItemKind},
+    stmt_data_loading::{
+        AlterFileFormatOperation, AlterStageOperation, FileStagingCommand, StageLoadSelectItemKind,
+    },
 };
 
 use core::cmp::Ordering;
@@ -4244,6 +4246,15 @@ pub enum Statement {
         show_options: ShowStatementOptions,
     },
     /// ```sql
+    /// SHOW FILE FORMATS [ LIKE '<pattern>' ] [ IN { ACCOUNT | DATABASE | SCHEMA } ]
+    /// ```
+    /// Snowflake-specific statement.
+    /// <https://docs.snowflake.com/en/sql-reference/sql/show-file-formats>
+    ShowFileFormats {
+        /// Additional options for filtering and scoping the file format listing.
+        show_options: ShowStatementOptions,
+    },
+    /// ```sql
     /// SHOW VIEWS
     /// ```
     ShowViews {
@@ -4547,6 +4558,18 @@ pub enum Statement {
         operation: AlterStageOperation,
     },
     /// ```sql
+    /// ALTER FILE FORMAT
+    /// ```
+    /// See <https://docs.snowflake.com/en/sql-reference/sql/alter-file-format>
+    AlterFileFormat {
+        /// `IF EXISTS` flag.
+        if_exists: bool,
+        /// File format name.
+        name: ObjectName,
+        /// File format alteration to perform.
+        operation: AlterFileFormatOperation,
+    },
+    /// ```sql
     /// CREATE FILE FORMAT
     /// ```
     /// See <https://docs.snowflake.com/en/sql-reference/sql/create-file-format>
@@ -4685,6 +4708,18 @@ pub enum Statement {
         stage_name: ObjectName,
     },
     /// ```sql
+    /// DESC[RIBE] FILE FORMAT <name>
+    /// ```
+    /// Snowflake-specific statement.
+    /// <https://docs.snowflake.com/en/sql-reference/sql/desc-file-format>
+    DescribeFileFormat {
+        /// `DESC | DESCRIBE` spelling used by the input statement.
+        describe_alias: DescribeAlias,
+        /// File format name.
+        #[cfg_attr(feature = "visitor", visit(with = "visit_relation"))]
+        name: ObjectName,
+    },
+    /// ```sql
     /// [EXPLAIN | DESC | DESCRIBE]  <statement>
     /// ```
     Explain {
@@ -5185,6 +5220,10 @@ impl fmt::Display for Statement {
                 describe_alias,
                 stage_name,
             } => write!(f, "{describe_alias} STAGE {stage_name}"),
+            Statement::DescribeFileFormat {
+                describe_alias,
+                name,
+            } => write!(f, "{describe_alias} FILE FORMAT {name}"),
             Statement::Explain {
                 describe_alias,
                 verbose,
@@ -5999,6 +6038,9 @@ impl fmt::Display for Statement {
             Statement::ShowStages { show_options } => {
                 write!(f, "SHOW STAGES{show_options}")
             }
+            Statement::ShowFileFormats { show_options } => {
+                write!(f, "SHOW FILE FORMATS{show_options}")
+            }
             Statement::ShowViews {
                 terse,
                 materialized,
@@ -6356,6 +6398,32 @@ impl fmt::Display for Statement {
                     }
                 }
             }
+            Statement::AlterFileFormat {
+                if_exists,
+                name,
+                operation,
+            } => {
+                write!(
+                    f,
+                    "ALTER FILE FORMAT {if_exists}{name}",
+                    if_exists = if *if_exists { "IF EXISTS " } else { "" },
+                )?;
+                match operation {
+                    AlterFileFormatOperation::RenameTo { new_name } => {
+                        write!(f, " RENAME TO {new_name}")
+                    }
+                    AlterFileFormatOperation::Set { options, comment } => {
+                        write!(f, " SET")?;
+                        if !options.options.is_empty() {
+                            write!(f, " {options}")?;
+                        }
+                        if let Some(comment) = comment {
+                            write!(f, " COMMENT='{comment}'")?;
+                        }
+                        Ok(())
+                    }
+                }
+            }
             Statement::CreateFileFormat {
                 or_replace,
                 temporary,
@@ -8686,6 +8754,8 @@ pub enum ObjectType {
     Sequence,
     /// A stage.
     Stage,
+    /// A named file format.
+    FileFormat,
     /// A type definition.
     Type,
     /// A user.
@@ -8707,6 +8777,7 @@ impl fmt::Display for ObjectType {
             ObjectType::Role => "ROLE",
             ObjectType::Sequence => "SEQUENCE",
             ObjectType::Stage => "STAGE",
+            ObjectType::FileFormat => "FILE FORMAT",
             ObjectType::Type => "TYPE",
             ObjectType::User => "USER",
             ObjectType::Stream => "STREAM",

src/ast/spans.rs

@@ -285,6 +285,7 @@ impl Spanned for Values {
 /// - [Statement::ShowColumns]
 /// - [Statement::ShowTables]
 /// - [Statement::ShowStages]
+/// - [Statement::ShowFileFormats]
 /// - [Statement::ShowCollation]
 /// - [Statement::StartTransaction]
 /// - [Statement::Comment]
@@ -300,6 +301,7 @@ impl Spanned for Values {
 /// - [Statement::CreateMacro]
 /// - [Statement::CreateStage]
 /// - [Statement::AlterStage]
+/// - [Statement::AlterFileFormat]
 /// - [Statement::Assert]
 /// - [Statement::Grant]
 /// - [Statement::Revoke]
@@ -309,6 +311,7 @@ impl Spanned for Values {
 /// - [Statement::Kill]
 /// - [Statement::ExplainTable]
 /// - [Statement::DescribeStage]
+/// - [Statement::DescribeFileFormat]
 /// - [Statement::Explain]
 /// - [Statement::Savepoint]
 /// - [Statement::ReleaseSavepoint]
@@ -447,6 +450,7 @@ impl Spanned for Statement {
             Statement::ShowColumns { .. } => Span::empty(),
             Statement::ShowTables { .. } => Span::empty(),
             Statement::ShowStages { .. } => Span::empty(),
+            Statement::ShowFileFormats { .. } => Span::empty(),
             Statement::ShowCollation { .. } => Span::empty(),
             Statement::ShowCharset { .. } => Span::empty(),
             Statement::Use(u) => u.span(),
@@ -465,6 +469,7 @@ impl Spanned for Statement {
             Statement::CreateMacro { .. } => Span::empty(),
             Statement::CreateStage { .. } => Span::empty(),
             Statement::AlterStage { .. } => Span::empty(),
+            Statement::AlterFileFormat { .. } => Span::empty(),
             Statement::CreateFileFormat { .. } => Span::empty(),
             Statement::Assert { .. } => Span::empty(),
             Statement::Grant { .. } => Span::empty(),
@@ -476,6 +481,7 @@ impl Spanned for Statement {
             Statement::Kill { .. } => Span::empty(),
             Statement::ExplainTable { .. } => Span::empty(),
             Statement::DescribeStage { .. } => Span::empty(),
+            Statement::DescribeFileFormat { .. } => Span::empty(),
             Statement::Explain { .. } => Span::empty(),
             Statement::Savepoint { .. } => Span::empty(),
             Statement::ReleaseSavepoint { .. } => Span::empty(),

src/dialect/mod.rs

@@ -1257,6 +1257,12 @@ pub trait Dialect: Debug + Any {
         false
     }
 
+    /// Returns true if this dialect supports Snowflake-style named file format
+    /// lifecycle commands (`ALTER`, `DROP`, `SHOW`, and `DESCRIBE`).
+    fn supports_file_format_commands(&self) -> bool {
+        false
+    }
+
     /// Returns true if this dialect supports the `COMMENT` statement
     fn supports_comment_on(&self) -> bool {
         false

src/dialect/snowflake.rs

@@ -24,8 +24,8 @@ use crate::ast::helpers::key_value_options::{
 use crate::ast::helpers::stmt_create_database::CreateDatabaseBuilder;
 use crate::ast::helpers::stmt_create_table::CreateTableBuilder;
 use crate::ast::helpers::stmt_data_loading::{
-    AlterStageOperation, FileStagingCommand, StageLoadSelectItem, StageLoadSelectItemKind,
-    StageParamsObject,
+    AlterFileFormatOperation, AlterStageOperation, FileStagingCommand, StageLoadSelectItem,
+    StageLoadSelectItemKind, StageParamsObject,
 };
 use crate::ast::{
     AlterTable, AlterTableOperation, AlterTableType, CatalogSyncNamespaceMode, CloudProviderParams,
@@ -303,6 +303,10 @@ impl Dialect for SnowflakeDialect {
             return Some(parse_alter_stage(parser));
         }
 
+        if parser.parse_keywords(&[Keyword::ALTER, Keyword::FILE, Keyword::FORMAT]) {
+            return Some(parse_alter_file_format(parser));
+        }
+
         if parser.parse_keyword(Keyword::CREATE) {
             // possibly CREATE STAGE
             //[ OR  REPLACE ]
@@ -492,6 +496,10 @@ impl Dialect for SnowflakeDialect {
         true
     }
 
+    fn supports_file_format_commands(&self) -> bool {
+        true
+    }
+
     fn supports_left_associative_joins_without_parens(&self) -> bool {
         false
     }
@@ -1459,6 +1467,37 @@ fn parse_alter_stage(parser: &mut Parser) -> Result<Statement, ParserError> {
     })
 }
 
+fn parse_alter_file_format(parser: &mut Parser) -> Result<Statement, ParserError> {
+    let if_exists = parser.parse_keywords(&[Keyword::IF, Keyword::EXISTS]);
+    let name = parser.parse_object_name(false)?;
+    let operation = if parser.parse_keyword(Keyword::RENAME) {
+        parser.expect_keyword(Keyword::TO)?;
+        AlterFileFormatOperation::RenameTo {
+            new_name: parser.parse_object_name(false)?,
+        }
+    } else if parser.parse_keyword(Keyword::SET) {
+        let options = parser.parse_key_value_options(false, &[Keyword::COMMENT])?;
+        let comment = if parser.parse_keyword(Keyword::COMMENT) {
+            parser.expect_token(&Token::Eq)?;
+            Some(parser.parse_comment_value()?)
+        } else {
+            None
+        };
+        if options.options.is_empty() && comment.is_none() {
+            return parser.expected_ref("a file format property", parser.peek_token_ref());
+        }
+        AlterFileFormatOperation::Set { options, comment }
+    } else {
+        return parser.expected_ref("RENAME TO or SET", parser.peek_token_ref());
+    };
+
+    Ok(Statement::AlterFileFormat {
+        if_exists,
+        name,
+        operation,
+    })
+}
+
 pub fn parse_create_file_format(
     or_replace: bool,
     temporary: bool,

src/keywords.rs

@@ -448,6 +448,7 @@ define_keywords!(
     FORCE_QUOTE,
     FOREIGN,
     FORMAT,
+    FORMATS,
     FORMATTED,
     FORWARD,
     FRAME_ROW,

src/parser/mod.rs

@@ -7394,6 +7394,10 @@ impl<'a> Parser<'a> {
             ObjectType::Sequence
         } else if self.parse_keyword(Keyword::STAGE) {
             ObjectType::Stage
+        } else if self.dialect.supports_file_format_commands()
+            && self.parse_keywords(&[Keyword::FILE, Keyword::FORMAT])
+        {
+            ObjectType::FileFormat
         } else if self.parse_keyword(Keyword::TYPE) {
             ObjectType::Type
         } else if self.parse_keyword(Keyword::USER) {
@@ -7427,7 +7431,7 @@ impl<'a> Parser<'a> {
             };
         } else {
             return self.expected_ref(
-                "COLLATION, CONNECTOR, DATABASE, EXTENSION, FUNCTION, INDEX, OPERATOR, POLICY, PROCEDURE, ROLE, SCHEMA, SECRET, SEQUENCE, STAGE, TABLE, TRIGGER, TYPE, VIEW, MATERIALIZED VIEW or USER after DROP",
+                "COLLATION, CONNECTOR, DATABASE, EXTENSION, FILE FORMAT, FUNCTION, INDEX, OPERATOR, POLICY, PROCEDURE, ROLE, SCHEMA, SECRET, SEQUENCE, STAGE, TABLE, TRIGGER, TYPE, VIEW, MATERIALIZED VIEW or USER after DROP",
                 self.peek_token_ref(),
             );
         };
@@ -14030,6 +14034,16 @@ impl<'a> Parser<'a> {
             });
         }
 
+        if describe_alias != DescribeAlias::Explain
+            && self.dialect.supports_file_format_commands()
+            && self.parse_keywords(&[Keyword::FILE, Keyword::FORMAT])
+        {
+            return Ok(Statement::DescribeFileFormat {
+                describe_alias,
+                name: self.parse_object_name(false)?,
+            });
+        }
+
         match self.maybe_parse(|parser| parser.parse_statement())? {
             Some(Statement::Explain { .. }) | Some(Statement::ExplainTable { .. }) => Err(
                 ParserError::ParserError("Explain must be root of the plan".to_string()),
@@ -15540,6 +15554,18 @@ impl<'a> Parser<'a> {
             Ok(Statement::ShowStages {
                 show_options: self.parse_show_stmt_options()?,
             })
+        } else if self.dialect.supports_file_format_commands()
+            && self.parse_keywords(&[Keyword::FILE, Keyword::FORMATS])
+        {
+            if terse || extended || full || session || global || external {
+                Err(ParserError::ParserError(
+                    "SHOW FILE FORMATS does not support SHOW modifiers".to_string(),
+                ))
+            } else {
+                Ok(Statement::ShowFileFormats {
+                    show_options: self.parse_show_stmt_options()?,
+                })
+            }
         } else if self.parse_keywords(&[Keyword::MATERIALIZED, Keyword::VIEWS]) {
             Ok(self.parse_show_views(terse, true)?)
         } else if self.parse_keyword(Keyword::VIEWS) {