feat: Support SHOW CREATE TABLE|EVENT|FUNCTION (MySQL specific) (apache#338)

* feat: Support SHOW CREATE TABLE|EVENT|FUNCTION (MySQL specific)

* misc: Simplify test with loop over enum values

Author: ovr

src/ast/mod.rs

@@ -523,6 +523,28 @@ impl fmt::Display for AddDropSync {
     }
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub enum ShowCreateObject {
+    Event,
+    Function,
+    Procedure,
+    Table,
+    Trigger,
+}
+
+impl fmt::Display for ShowCreateObject {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            ShowCreateObject::Event => f.write_str("EVENT"),
+            ShowCreateObject::Function => f.write_str("FUNCTION"),
+            ShowCreateObject::Procedure => f.write_str("PROCEDURE"),
+            ShowCreateObject::Table => f.write_str("TABLE"),
+            ShowCreateObject::Trigger => f.write_str("TRIGGER"),
+        }
+    }
+}
+
 /// A top-level statement (SELECT, INSERT, CREATE, etc.)
 #[allow(clippy::large_enum_variant)]
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
@@ -685,6 +707,13 @@ pub enum Statement {
     ///
     /// Note: this is a PostgreSQL-specific statement.
     ShowVariable { variable: Vec<Ident> },
+    /// SHOW CREATE TABLE
+    ///
+    /// Note: this is a MySQL-specific statement.
+    ShowCreate {
+        obj_type: ShowCreateObject,
+        obj_name: ObjectName,
+    },
     /// SHOW COLUMNS
     ///
     /// Note: this is a MySQL-specific statement.
@@ -1196,6 +1225,15 @@ impl fmt::Display for Statement {
                 }
                 Ok(())
             }
+            Statement::ShowCreate { obj_type, obj_name } => {
+                write!(
+                    f,
+                    "SHOW CREATE {obj_type} {obj_name}",
+                    obj_type = obj_type,
+                    obj_name = obj_name,
+                )?;
+                Ok(())
+            }
             Statement::ShowColumns {
                 extended,
                 full,

src/dialect/keywords.rs

@@ -193,6 +193,7 @@ define_keywords!(
     EQUALS,
     ERROR,
     ESCAPE,
+    EVENT,
     EVERY,
     EXCEPT,
     EXEC,

src/parser.rs

@@ -2541,14 +2541,40 @@ impl<'a> Parser<'a> {
             .is_some()
         {
             self.prev_token();
-            self.parse_show_columns()
+            Ok(self.parse_show_columns()?)
+        } else if self.parse_one_of_keywords(&[Keyword::CREATE]).is_some() {
+            Ok(self.parse_show_create()?)
         } else {
             Ok(Statement::ShowVariable {
                 variable: self.parse_identifiers()?,
             })
         }
     }
 
+    fn parse_show_create(&mut self) -> Result<Statement, ParserError> {
+        let obj_type = match self.expect_one_of_keywords(&[
+            Keyword::TABLE,
+            Keyword::TRIGGER,
+            Keyword::FUNCTION,
+            Keyword::PROCEDURE,
+            Keyword::EVENT,
+        ])? {
+            Keyword::TABLE => Ok(ShowCreateObject::Table),
+            Keyword::TRIGGER => Ok(ShowCreateObject::Trigger),
+            Keyword::FUNCTION => Ok(ShowCreateObject::Function),
+            Keyword::PROCEDURE => Ok(ShowCreateObject::Procedure),
+            Keyword::EVENT => Ok(ShowCreateObject::Event),
+            keyword => Err(ParserError::ParserError(format!(
+                "Unable to map keyword to ShowCreateObject: {:?}",
+                keyword
+            ))),
+        }?;
+
+        let obj_name = self.parse_object_name()?;
+
+        Ok(Statement::ShowCreate { obj_type, obj_name })
+    }
+
     fn parse_show_columns(&mut self) -> Result<Statement, ParserError> {
         let extended = self.parse_keyword(Keyword::EXTENDED);
         let full = self.parse_keyword(Keyword::FULL);

tests/sqlparser_mysql.rs

@@ -100,6 +100,27 @@ fn parse_show_columns() {
     }
 }
 
+#[test]
+fn parse_show_create() {
+    let obj_name = ObjectName(vec![Ident::new("myident")]);
+
+    for obj_type in &vec![
+        ShowCreateObject::Table,
+        ShowCreateObject::Trigger,
+        ShowCreateObject::Event,
+        ShowCreateObject::Function,
+        ShowCreateObject::Procedure,
+    ] {
+        assert_eq!(
+            mysql_and_generic().verified_stmt(format!("SHOW CREATE {} myident", obj_type).as_str()),
+            Statement::ShowCreate {
+                obj_type: obj_type.clone(),
+                obj_name: obj_name.clone(),
+            }
+        );
+    }
+}
+
 #[test]
 fn parse_create_table_auto_increment() {
     let sql = "CREATE TABLE foo (bar INT PRIMARY KEY AUTO_INCREMENT)";