[MySQL, Oracle] Parse optimizer hints for DELETEs

Author: xitep

src/ast/dml.rs

@@ -196,6 +196,11 @@ impl Display for Insert {
 pub struct Delete {
     /// Token for the `DELETE` keyword
     pub delete_token: AttachedToken,
+    /// A query optimizer hint
+    ///
+    /// [MySQL](https://dev.mysql.com/doc/refman/8.4/en/optimizer-hints.html)
+    /// [Oracle](https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/Comments.html#GUID-D316D545-89E2-4D54-977F-FC97815CD62E)
+    pub optimizer_hint: Option<OptimizerHint>,
     /// Multi tables delete are supported in mysql
     pub tables: Vec<ObjectName>,
     /// FROM
@@ -215,6 +220,10 @@ pub struct Delete {
 impl Display for Delete {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.write_str("DELETE")?;
+        if let Some(hint) = self.optimizer_hint.as_ref() {
+            f.write_str(" ")?;
+            hint.fmt(f)?;
+        }
         if !self.tables.is_empty() {
             indented_list(f, &self.tables)?;
         }

src/ast/spans.rs

@@ -894,6 +894,7 @@ impl Spanned for Delete {
     fn span(&self) -> Span {
         let Delete {
             delete_token,
+            optimizer_hint: _,
             tables,
             from,
             using,

src/parser/mod.rs

@@ -12985,6 +12985,7 @@ impl<'a> Parser<'a> {
 
     /// Parse a `DELETE` statement and return `Statement::Delete`.
     pub fn parse_delete(&mut self, delete_token: TokenWithSpan) -> Result<Statement, ParserError> {
+        let optimizer_hint = self.parse_optional_optimizer_hint()?;
         let (tables, with_from_keyword) = if !self.parse_keyword(Keyword::FROM) {
             // `FROM` keyword is optional in BigQuery SQL.
             // https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#delete_statement
@@ -13028,6 +13029,7 @@ impl<'a> Parser<'a> {
 
         Ok(Statement::Delete(Delete {
             delete_token: delete_token.into(),
+            optimizer_hint,
             tables,
             from: if with_from_keyword {
                 FromTable::WithFromKeyword(from)

tests/sqlparser_mysql.rs

@@ -4392,4 +4392,8 @@ fn test_optimizer_hints() {
        UPDATE /*+ quux */ table_name \
        SET column1 = 1 \
        WHERE 1 = 1");
+
+    // ~ deletes
+    mysql_dialect.verified_stmt("\
+       DELETE /*+ foobar */ FROM table_name");
 }

tests/sqlparser_oracle.rs

@@ -376,4 +376,8 @@ fn test_optimizer_hints() {
     // ~ updates
     oracle_dialect.verified_stmt(
         "UPDATE /*+ DISABLE_PARALLEL_DML */ table_name SET column1 = 1");
+
+    // ~ deletes
+    oracle_dialect.verified_stmt(
+        "DELETE --+ ENABLE_PARALLEL_DML\n FROM table_name");
 }