refactor(clickhouse): move dialect_of! checks to Dialect trait methods

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: crilopez

src/dialect/clickhouse.rs

@@ -64,6 +64,14 @@ impl Dialect for ClickHouseDialect {
         true
     }
 
+    fn supports_partition_by_after_order_by(&self) -> bool {
+        true
+    }
+
+    fn supports_array_join_syntax(&self) -> bool {
+        true
+    }
+
     // ClickHouse uses this for some FORMAT expressions in `INSERT` context, e.g. when inserting
     // with FORMAT JSONEachRow a raw JSON key-value expression is valid and expected.
     //

src/dialect/generic.rs

@@ -45,6 +45,14 @@ impl Dialect for GenericDialect {
         true
     }
 
+    fn supports_partition_by_after_order_by(&self) -> bool {
+        true
+    }
+
+    fn supports_array_join_syntax(&self) -> bool {
+        true
+    }
+
     fn supports_group_by_expr(&self) -> bool {
         true
     }

src/dialect/mod.rs

@@ -345,6 +345,23 @@ pub trait Dialect: Debug + Any {
         false
     }
 
+    /// Returns true if the dialect supports `PARTITION BY` appearing after `ORDER BY`
+    /// in a `CREATE TABLE` statement (in addition to the standard placement before `ORDER BY`).
+    ///
+    /// ClickHouse DDL uses this ordering:
+    /// <https://clickhouse.com/docs/en/sql-reference/statements/create/table#partition-by>
+    fn supports_partition_by_after_order_by(&self) -> bool {
+        false
+    }
+
+    /// Returns true if the dialect supports ClickHouse-style `ARRAY JOIN` / `LEFT ARRAY JOIN` /
+    /// `INNER ARRAY JOIN` syntax for unnesting arrays inline.
+    ///
+    /// <https://clickhouse.com/docs/en/sql-reference/statements/select/array-join>
+    fn supports_array_join_syntax(&self) -> bool {
+        false
+    }
+
     /// Returns true if the dialects supports `group sets, roll up, or cube` expressions.
     fn supports_group_by_expr(&self) -> bool {
         false

src/parser/mod.rs

@@ -8567,7 +8567,7 @@ impl<'a> Parser<'a> {
         // ClickHouse allows PARTITION BY after ORDER BY
         // https://clickhouse.com/docs/en/sql-reference/statements/create/table#partition-by
         let partition_by = if create_table_config.partition_by.is_none()
-            && dialect_of!(self is ClickHouseDialect | GenericDialect)
+            && self.dialect.supports_partition_by_after_order_by()
             && self.parse_keywords(&[Keyword::PARTITION, Keyword::BY])
         {
             Some(Box::new(self.parse_expr()?))
@@ -15749,7 +15749,7 @@ impl<'a> Parser<'a> {
                         constraint: self.parse_join_constraint(false)?,
                     },
                 }
-            } else if dialect_of!(self is ClickHouseDialect | GenericDialect)
+            } else if self.dialect.supports_array_join_syntax()
                 && self.parse_keywords(&[Keyword::INNER, Keyword::ARRAY, Keyword::JOIN])
             {
                 // ClickHouse: INNER ARRAY JOIN
@@ -15758,7 +15758,7 @@ impl<'a> Parser<'a> {
                     global,
                     join_operator: JoinOperator::InnerArrayJoin,
                 }
-            } else if dialect_of!(self is ClickHouseDialect | GenericDialect)
+            } else if self.dialect.supports_array_join_syntax()
                 && self.parse_keywords(&[Keyword::LEFT, Keyword::ARRAY, Keyword::JOIN])
             {
                 // ClickHouse: LEFT ARRAY JOIN
@@ -15767,7 +15767,7 @@ impl<'a> Parser<'a> {
                     global,
                     join_operator: JoinOperator::LeftArrayJoin,
                 }
-            } else if dialect_of!(self is ClickHouseDialect | GenericDialect)
+            } else if self.dialect.supports_array_join_syntax()
                 && self.parse_keywords(&[Keyword::ARRAY, Keyword::JOIN])
             {
                 // ClickHouse: ARRAY JOIN