Support ALTER VIEW, MySQL syntax (#907)

Co-authored-by: Andrew Lamb <andrew@nerdnetworks.org>

src/ast/mod.rs

@@ -1375,6 +1375,15 @@ pub enum Statement {
         name: ObjectName,
         operation: AlterIndexOperation,
     },
+    /// ALTER VIEW
+    AlterView {
+        /// View name
+        #[cfg_attr(feature = "visitor", visit(with = "visit_relation"))]
+        name: ObjectName,
+        columns: Vec<Ident>,
+        query: Box<Query>,
+        with_options: Vec<SqlOption>,
+    },
     /// DROP
     Drop {
         /// The type of the object to drop: TABLE, VIEW, etc.
@@ -2534,6 +2543,21 @@ impl fmt::Display for Statement {
             Statement::AlterIndex { name, operation } => {
                 write!(f, "ALTER INDEX {name} {operation}")
             }
+            Statement::AlterView {
+                name,
+                columns,
+                query,
+                with_options,
+            } => {
+                write!(f, "ALTER VIEW {name}")?;
+                if !with_options.is_empty() {
+                    write!(f, " WITH ({})", display_comma_separated(with_options))?;
+                }
+                if !columns.is_empty() {
+                    write!(f, " ({})", display_comma_separated(columns))?;
+                }
+                write!(f, " AS {query}")
+            }
             Statement::Drop {
                 object_type,
                 if_exists,

src/parser.rs

@@ -3898,8 +3898,10 @@ impl<'a> Parser<'a> {
     }
 
     pub fn parse_alter(&mut self) -> Result<Statement, ParserError> {
-        let object_type = self.expect_one_of_keywords(&[Keyword::TABLE, Keyword::INDEX])?;
+        let object_type =
+            self.expect_one_of_keywords(&[Keyword::VIEW, Keyword::TABLE, Keyword::INDEX])?;
         match object_type {
+            Keyword::VIEW => self.parse_alter_view(),
             Keyword::TABLE => {
                 let _ = self.parse_keyword(Keyword::ONLY); // [ ONLY ]
                 let table_name = self.parse_object_name()?;
@@ -4097,6 +4099,23 @@ impl<'a> Parser<'a> {
         }
     }
 
+    pub fn parse_alter_view(&mut self) -> Result<Statement, ParserError> {
+        let name = self.parse_object_name()?;
+        let columns = self.parse_parenthesized_column_list(Optional, false)?;
+
+        let with_options = self.parse_options(Keyword::WITH)?;
+
+        self.expect_keyword(Keyword::AS)?;
+        let query = Box::new(self.parse_query()?);
+
+        Ok(Statement::AlterView {
+            name,
+            columns,
+            query,
+            with_options,
+        })
+    }
+
     /// Parse a copy statement
     pub fn parse_copy(&mut self) -> Result<Statement, ParserError> {
         let source;