Support CREATE TABLE ON UPDATE <expr> Function (#685)

* feat : OnUpdate Function Implement

* feat : add GenericDialect Options

Author: CEOJINSUNG

src/ast/ddl.rs

@@ -558,6 +558,7 @@ pub enum ColumnOption {
     DialectSpecific(Vec<Token>),
     CharacterSet(ObjectName),
     Comment(String),
+    OnUpdate(Expr),
 }
 
 impl fmt::Display for ColumnOption {
@@ -592,6 +593,7 @@ impl fmt::Display for ColumnOption {
             DialectSpecific(val) => write!(f, "{}", display_separated(val, " ")),
             CharacterSet(n) => write!(f, "CHARACTER SET {}", n),
             Comment(v) => write!(f, "COMMENT '{}'", escape_single_quote_string(v)),
+            OnUpdate(expr) => write!(f, "ON UPDATE {}", expr),
         }
     }
 }

src/parser.rs

@@ -3474,11 +3474,10 @@ impl<'a> Parser<'a> {
                 Token::make_keyword("AUTOINCREMENT"),
             ])))
         } else if self.parse_keywords(&[Keyword::ON, Keyword::UPDATE])
-            && dialect_of!(self is MySqlDialect)
+            && dialect_of!(self is MySqlDialect | GenericDialect)
         {
-            Ok(Some(ColumnOption::DialectSpecific(vec![
-                Token::make_keyword("ON UPDATE"),
-            ])))
+            let expr = self.parse_expr()?;
+            Ok(Some(ColumnOption::OnUpdate(expr)))
         } else {
             Ok(None)
         }

tests/sqlparser_mysql.rs

@@ -1031,7 +1031,7 @@ fn parse_kill() {
 
 #[test]
 fn parse_table_colum_option_on_update() {
-    let sql1 = "CREATE TABLE foo (`modification_time` DATETIME ON UPDATE)";
+    let sql1 = "CREATE TABLE foo (`modification_time` DATETIME ON UPDATE CURRENT_TIMESTAMP())";
     match mysql().verified_stmt(sql1) {
         Statement::CreateTable { name, columns, .. } => {
             assert_eq!(name.to_string(), "foo");
@@ -1042,9 +1042,13 @@ fn parse_table_colum_option_on_update() {
                     collation: None,
                     options: vec![ColumnOptionDef {
                         name: None,
-                        option: ColumnOption::DialectSpecific(vec![Token::make_keyword(
-                            "ON UPDATE"
-                        )]),
+                        option: ColumnOption::OnUpdate(Expr::Function(Function {
+                            name: ObjectName(vec![Ident::new("CURRENT_TIMESTAMP")]),
+                            args: vec![],
+                            over: None,
+                            distinct: false,
+                            special: false,
+                        })),
                     },],
                 }],
                 columns