Extend exception handling (#1884)

tests/sqlparser_bigquery.rs

@@ -261,10 +261,10 @@ fn parse_at_at_identifier() {
 
 #[test]
 fn parse_begin() {
-    let sql = r#"BEGIN SELECT 1; EXCEPTION WHEN ERROR THEN SELECT 2; END"#;
+    let sql = r#"BEGIN SELECT 1; EXCEPTION WHEN ERROR THEN SELECT 2; RAISE USING MESSAGE = FORMAT('ERR: %s', 'Bad'); END"#;
     let Statement::StartTransaction {
         statements,
-        exception_statements,
+        exception,
         has_end_keyword,
         ..
     } = bigquery().verified_stmt(sql)
@@ -272,7 +272,10 @@ fn parse_begin() {
         unreachable!();
     };
     assert_eq!(1, statements.len());
-    assert_eq!(1, exception_statements.unwrap().len());
+    assert!(exception.is_some());
+
+    let exception = exception.unwrap();
+    assert_eq!(1, exception.len());
     assert!(has_end_keyword);
 
     bigquery().verified_stmt(

tests/sqlparser_common.rs

@@ -8592,8 +8592,11 @@ fn lateral_function() {
 #[test]
 fn parse_start_transaction() {
     let dialects = all_dialects_except(|d|
-        // BigQuery does not support this syntax
-        d.is::<BigQueryDialect>());
+        // BigQuery and Snowflake does not support this syntax
+        //
+        // BigQuery: <https://cloud.google.com/bigquery/docs/reference/standard-sql/procedural-language#begin_transaction>
+        // Snowflake: <https://docs.snowflake.com/en/sql-reference/sql/begin>
+        d.is::<BigQueryDialect>() || d.is::<SnowflakeDialect>());
     match dialects
         .verified_stmt("START TRANSACTION READ ONLY, READ WRITE, ISOLATION LEVEL SERIALIZABLE")
     {

tests/sqlparser_snowflake.rs

@@ -4082,3 +4082,67 @@ fn parse_connect_by_root_operator() {
         "sql parser error: Expected an expression, found: FROM"
     );
 }
+
+#[test]
+fn test_begin_exception_end() {
+    for sql in [
+        "BEGIN SELECT 1; EXCEPTION WHEN OTHER THEN SELECT 2; RAISE; END",
+        "BEGIN SELECT 1; EXCEPTION WHEN OTHER THEN SELECT 2; RAISE EX_1; END",
+        "BEGIN SELECT 1; EXCEPTION WHEN FOO THEN SELECT 2; WHEN OTHER THEN SELECT 3; RAISE; END",
+        "BEGIN BEGIN SELECT 1; EXCEPTION WHEN OTHER THEN SELECT 2; RAISE; END; END",
+    ] {
+        snowflake().verified_stmt(sql);
+    }
+
+    let sql = r#"
+DECLARE
+  EXCEPTION_1 EXCEPTION (-20001, 'I caught the expected exception.');
+  EXCEPTION_2 EXCEPTION (-20002, 'Not the expected exception!');
+  EXCEPTION_3 EXCEPTION (-20003, 'The worst exception...');
+BEGIN
+    BEGIN
+        SELECT 1;
+    EXCEPTION
+        WHEN EXCEPTION_1 THEN
+            SELECT 1;
+        WHEN EXCEPTION_2 OR EXCEPTION_3 THEN
+            SELECT 2;
+            SELECT 3;
+        WHEN OTHER THEN
+            SELECT 4;
+    RAISE;
+    END;
+END
+"#;
+
+    // Outer `BEGIN` of the two nested `BEGIN` statements.
+    let Statement::StartTransaction { mut statements, .. } = snowflake()
+        .parse_sql_statements(sql)
+        .unwrap()
+        .pop()
+        .unwrap()
+    else {
+        unreachable!();
+    };
+
+    // Inner `BEGIN` of the two nested `BEGIN` statements.
+    let Statement::StartTransaction {
+        statements,
+        exception,
+        has_end_keyword,
+        ..
+    } = statements.pop().unwrap()
+    else {
+        unreachable!();
+    };
+
+    assert_eq!(1, statements.len());
+    assert!(has_end_keyword);
+
+    let exception = exception.unwrap();
+    assert_eq!(3, exception.len());
+    assert_eq!(1, exception[0].idents.len());
+    assert_eq!(1, exception[0].statements.len());
+    assert_eq!(2, exception[1].idents.len());
+    assert_eq!(2, exception[1].statements.len());
+}