fix: Use separate types for FormatClause and InputFormatClause

src/ast/dml.rs

@@ -32,8 +32,8 @@ use sqlparser_derive::{Visit, VisitMut};
 pub use super::ddl::{ColumnDef, TableConstraint};
 
 use super::{
-    display_comma_separated, display_separated, Assignment, ClusteredBy, CommentDef, Expr,
-    FileFormat, FormatClause, FromTable, HiveDistributionStyle, HiveFormat, HiveIOFormat,
+    display_comma_separated, display_separated, query::InputFormatClause, Assignment, ClusteredBy,
+    CommentDef, Expr, FileFormat, FromTable, HiveDistributionStyle, HiveFormat, HiveIOFormat,
     HiveRowFormat, Ident, InsertAliases, MysqlInsertPriority, ObjectName, OnCommit, OnInsert,
     OneOrManyWithParens, OrderByExpr, Query, RowAccessPolicy, SelectItem, Setting, SqlOption,
     SqliteOnConflict, TableEngine, TableWithJoins, Tag, WrappedCollection,
@@ -510,7 +510,7 @@ pub struct Insert {
     /// ClickHouse syntax: `INSERT INTO tbl FORMAT JSONEachRow {"foo": 1, "bar": 2}, {"foo": 3}`
     ///
     /// [ClickHouse formats JSON insert](https://clickhouse.com/docs/en/interfaces/formats#json-inserting-data)
-    pub format_clause: Option<FormatClause>,
+    pub format_clause: Option<InputFormatClause>,
 }
 
 impl Display for Insert {

src/ast/mod.rs

@@ -61,10 +61,10 @@ pub use self::operator::{BinaryOperator, UnaryOperator};
 pub use self::query::{
     AfterMatchSkip, ConnectBy, Cte, CteAsMaterialized, Distinct, EmptyMatchesMode,
     ExceptSelectItem, ExcludeSelectItem, ExprWithAlias, Fetch, ForClause, ForJson, ForXml,
-    FormatClause, GroupByExpr, GroupByWithModifier, IdentWithAlias, IlikeSelectItem, Interpolate,
-    InterpolateExpr, Join, JoinConstraint, JoinOperator, JsonTableColumn,
-    JsonTableColumnErrorHandling, JsonTableNamedColumn, JsonTableNestedColumn, LateralView,
-    LockClause, LockType, MatchRecognizePattern, MatchRecognizeSymbol, Measure,
+    FormatClause, GroupByExpr, GroupByWithModifier, IdentWithAlias, IlikeSelectItem,
+    InputFormatClause, Interpolate, InterpolateExpr, Join, JoinConstraint, JoinOperator,
+    JsonTableColumn, JsonTableColumnErrorHandling, JsonTableNamedColumn, JsonTableNestedColumn,
+    LateralView, LockClause, LockType, MatchRecognizePattern, MatchRecognizeSymbol, Measure,
     NamedWindowDefinition, NamedWindowExpr, NonBlock, Offset, OffsetRows, OpenJsonTableColumn,
     OrderBy, OrderByExpr, PivotValueSource, ProjectionSelect, Query, RenameSelectItem,
     RepetitionQuantifier, ReplaceSelectElement, ReplaceSelectItem, RowsPerMatch, Select,

src/ast/query.rs

@@ -2465,27 +2465,39 @@ impl fmt::Display for GroupByExpr {
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum FormatClause {
-    Identifier {
-        ident: Ident,
-        expr: Option<Vec<Expr>>,
-    },
+    Identifier(Ident),
     Null,
 }
 
 impl fmt::Display for FormatClause {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
-            FormatClause::Identifier { ident, expr } => {
-                write!(f, "FORMAT {}", ident)?;
+            FormatClause::Identifier(ident) => write!(f, "FORMAT {}", ident),
+            FormatClause::Null => write!(f, "FORMAT NULL"),
+        }
+    }
+}
 
-                if let Some(exprs) = expr {
-                    write!(f, " {}", display_comma_separated(exprs))?;
-                }
+/// FORMAT identifier in input context, specific to ClickHouse.
+///
+/// [ClickHouse]: <https://clickhouse.com/docs/en/interfaces/formats>
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct InputFormatClause {
+    pub ident: Ident,
+    pub values: Vec<Expr>,
+}
 
-                Ok(())
-            }
-            FormatClause::Null => write!(f, "FORMAT NULL"),
+impl fmt::Display for InputFormatClause {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "FORMAT {}", self.ident)?;
+
+        if !self.values.is_empty() {
+            write!(f, " {}", display_comma_separated(self.values.as_slice()))?;
         }
+
+        Ok(())
     }
 }
 

src/parser/mod.rs

@@ -9589,7 +9589,12 @@ impl<'a> Parser<'a> {
             let format_clause = if dialect_of!(self is ClickHouseDialect | GenericDialect)
                 && self.parse_keyword(Keyword::FORMAT)
             {
-                Some(self.parse_format_clause(false)?)
+                if self.parse_keyword(Keyword::NULL) {
+                    Some(FormatClause::Null)
+                } else {
+                    let ident = self.parse_identifier()?;
+                    Some(FormatClause::Identifier(ident))
+                }
             } else {
                 None
             };
@@ -11934,7 +11939,7 @@ impl<'a> Parser<'a> {
                 let settings = self.parse_settings()?;
 
                 let format = if self.parse_keyword(Keyword::FORMAT) {
-                    Some(self.parse_format_clause(true)?)
+                    Some(self.parse_input_format_clause()?)
                 } else {
                     None
                 };
@@ -12035,32 +12040,17 @@ impl<'a> Parser<'a> {
     }
 
     // Parses format clause used for [ClickHouse]. Formats are different when using `SELECT` and
-    // `INSERT` and also when using the CLI for pipes. It may or may not take an additional
-    // expression after the format so we try to parse the expression but allow failure.
-    //
-    // Since we know we never take an additional expression in `SELECT` context we never only try
-    // to parse if `can_have_expression` is true.
+    // `INSERT` and also when using the CLI for pipes. For `INSERT` it can take an optional values
+    // list which we try to parse here.
     //
     // <https://clickhouse.com/docs/en/interfaces/formats>
-    pub fn parse_format_clause(
-        &mut self,
-        can_have_expression: bool,
-    ) -> Result<FormatClause, ParserError> {
-        if self.parse_keyword(Keyword::NULL) {
-            Ok(FormatClause::Null)
-        } else {
-            let ident = self.parse_identifier()?;
-            let expr = if can_have_expression {
-                match self.try_parse(|p| p.parse_comma_separated(|p| p.parse_expr())) {
-                    Ok(expr) => Some(expr),
-                    _ => None,
-                }
-            } else {
-                None
-            };
+    pub fn parse_input_format_clause(&mut self) -> Result<InputFormatClause, ParserError> {
+        let ident = self.parse_identifier()?;
+        let values = self
+            .try_parse(|p| p.parse_comma_separated(|p| p.parse_expr()))
+            .unwrap_or_default();
 
-            Ok(FormatClause::Identifier { ident, expr })
-        }
+        Ok(InputFormatClause { ident, values })
     }
 
     /// Returns true if the immediate tokens look like the

tests/sqlparser_clickhouse.rs

@@ -1378,10 +1378,7 @@ fn test_query_with_format_clause() {
                 } else {
                     assert_eq!(
                         query.format_clause,
-                        Some(FormatClause::Identifier {
-                            ident: Ident::new(*format),
-                            expr: None
-                        })
+                        Some(FormatClause::Identifier(Ident::new(*format))),
                     );
                 }
             }