Support BEGIN as standalon clause

Author: Vedin

src/parser/mod.rs

@@ -15597,6 +15597,25 @@ impl<'a> Parser<'a> {
     }
 
     pub fn parse_begin_exception_end(&mut self) -> Result<Statement, ParserError> {
+        // Snowflake allows BEGIN as a standalone transaction statement (no END).
+        // If the next token is a semicolon or EOF, treat it as a standalone BEGIN.
+        if dialect_of!(self is SnowflakeDialect) {
+            match &self.peek_token_ref().token {
+                Token::SemiColon | Token::EOF => {
+                    return Ok(Statement::StartTransaction {
+                        begin: true,
+                        statements: vec![],
+                        exception: None,
+                        has_end_keyword: false,
+                        transaction: None,
+                        modifier: None,
+                        modes: Default::default(),
+                    })
+                }
+                _ => {}
+            }
+        }
+
         let statements = self.parse_statement_list(&[Keyword::EXCEPTION, Keyword::END])?;
 
         let exception = if self.parse_keyword(Keyword::EXCEPTION) {
@@ -15628,17 +15647,30 @@ impl<'a> Parser<'a> {
             None
         };
 
-        self.expect_keyword(Keyword::END)?;
-
-        Ok(Statement::StartTransaction {
-            begin: true,
-            statements,
-            exception,
-            has_end_keyword: true,
-            transaction: None,
-            modifier: None,
-            modes: Default::default(),
-        })
+        if dialect_of!(self is SnowflakeDialect) {
+            // Make END optional for Snowflake. If present, set flag accordingly.
+            let has_end = self.parse_keyword(Keyword::END);
+            Ok(Statement::StartTransaction {
+                begin: true,
+                statements,
+                exception,
+                has_end_keyword: has_end,
+                transaction: None,
+                modifier: None,
+                modes: Default::default(),
+            })
+        } else {
+            self.expect_keyword(Keyword::END)?;
+            Ok(Statement::StartTransaction {
+                begin: true,
+                statements,
+                exception,
+                has_end_keyword: true,
+                transaction: None,
+                modifier: None,
+                modes: Default::default(),
+            })
+        }
     }
 
     pub fn parse_end(&mut self) -> Result<Statement, ParserError> {

tests/sqlparser_snowflake.rs

@@ -4343,6 +4343,40 @@ fn test_snowflake_fetch_clause_syntax() {
     );
 }
 
+#[test]
+fn test_snowflake_begin_standalone() {
+    // BEGIN; (no END) should be allowed for Snowflake
+    let mut stmts = snowflake().parse_sql_statements("BEGIN;").unwrap();
+    assert_eq!(1, stmts.len());
+    match stmts.remove(0) {
+        Statement::StartTransaction {
+            begin,
+            has_end_keyword,
+            statements,
+            ..
+        } => {
+            assert!(begin);
+            assert!(!has_end_keyword);
+            assert!(statements.is_empty());
+        }
+        other => panic!("unexpected stmt: {other:?}"),
+    }
+}
+
+#[test]
+fn test_snowflake_begin_commit_sequence() {
+    let mut stmts = snowflake().parse_sql_statements("BEGIN; COMMIT;").unwrap();
+    assert_eq!(2, stmts.len());
+    match stmts.remove(0) {
+        Statement::StartTransaction { begin, .. } => assert!(begin),
+        other => panic!("unexpected first stmt: {other:?}"),
+    }
+    match stmts.remove(0) {
+        Statement::Commit { end, .. } => assert!(!end),
+        other => panic!("unexpected second stmt: {other:?}"),
+    }
+}
+
 #[test]
 fn test_snowflake_create_view_with_multiple_column_options() {
     let create_view_with_tag =