Support views with explicit column names

A `CREATE VIEW` statement may provide names for its columns that
override the names of the columns derived from the view's query.

Author: benesch

src/sqlast/mod.rs

@@ -377,6 +377,7 @@ pub enum SQLStatement {
     SQLCreateView {
         /// View name
         name: SQLObjectName,
+        columns: Vec<SQLIdent>,
         query: Box<SQLQuery>,
         materialized: bool,
         with_options: Vec<SQLOption>,
@@ -474,6 +475,7 @@ impl ToString for SQLStatement {
             }
             SQLStatement::SQLCreateView {
                 name,
+                columns,
                 query,
                 materialized,
                 with_options,
@@ -484,12 +486,18 @@ impl ToString for SQLStatement {
                 } else {
                     "".into()
                 };
+                let columns = if !columns.is_empty() {
+                    format!(" ({})", comma_separated_string(columns))
+                } else {
+                    "".into()
+                };
                 format!(
-                    "CREATE{} VIEW {}{} AS {}",
+                    "CREATE{} VIEW {}{}{} AS {}",
                     modifier,
                     name.to_string(),
                     with_options,
-                    query.to_string()
+                    columns,
+                    query.to_string(),
                 )
             }
             SQLStatement::SQLCreateTable {

src/sqlparser.rs

@@ -775,7 +775,7 @@ impl Parser {
         // Many dialects support `OR REPLACE` | `OR ALTER` right after `CREATE`, but we don't (yet).
         // ANSI SQL and Postgres support RECURSIVE here, but we don't support it either.
         let name = self.parse_object_name()?;
-        // Parenthesized "output" columns list could be handled here.
+        let columns = self.parse_parenthesized_column_list(Optional)?;
         let with_options = if self.parse_keyword("WITH") {
             self.parse_with_options()?
         } else {
@@ -786,6 +786,7 @@ impl Parser {
         // Optional `WITH [ CASCADED | LOCAL ] CHECK OPTION` is widely supported here.
         Ok(SQLStatement::SQLCreateView {
             name,
+            columns,
             query,
             materialized,
             with_options,

tests/sqlparser_common.rs

@@ -1589,11 +1589,13 @@ fn parse_create_view() {
     match verified_stmt(sql) {
         SQLStatement::SQLCreateView {
             name,
+            columns,
             query,
             materialized,
             with_options,
         } => {
             assert_eq!("myschema.myview", name.to_string());
+            assert_eq!(Vec::<SQLIdent>::new(), columns);
             assert_eq!("SELECT foo FROM bar", query.to_string());
             assert!(!materialized);
             assert_eq!(with_options, vec![]);
@@ -1625,17 +1627,40 @@ fn parse_create_view_with_options() {
     }
 }
 
+#[test]
+fn parse_create_view_with_columns() {
+    let sql = "CREATE VIEW v (has, cols) AS SELECT 1, 2";
+    match verified_stmt(sql) {
+        SQLStatement::SQLCreateView {
+            name,
+            columns,
+            with_options,
+            query,
+            materialized,
+        } => {
+            assert_eq!("v", name.to_string());
+            assert_eq!(columns, vec!["has".to_string(), "cols".to_string()]);
+            assert_eq!(with_options, vec![]);
+            assert_eq!("SELECT 1, 2", query.to_string());
+            assert!(!materialized);
+        }
+        _ => unreachable!(),
+    }
+}
+
 #[test]
 fn parse_create_materialized_view() {
     let sql = "CREATE MATERIALIZED VIEW myschema.myview AS SELECT foo FROM bar";
     match verified_stmt(sql) {
         SQLStatement::SQLCreateView {
             name,
+            columns,
             query,
             materialized,
             with_options,
         } => {
             assert_eq!("myschema.myview", name.to_string());
+            assert_eq!(Vec::<SQLIdent>::new(), columns);
             assert_eq!("SELECT foo FROM bar", query.to_string());
             assert!(materialized);
             assert_eq!(with_options, vec![]);