Fix: Generic supports CREATE TYPE AS ENUM

Author: jvatic

src/dialect/postgresql.rs

@@ -28,7 +28,6 @@
 // limitations under the License.
 use log::debug;
 
-use crate::ast::{ObjectName, Statement, UserDefinedTypeRepresentation};
 use crate::dialect::{Dialect, Precedence};
 use crate::keywords::Keyword;
 use crate::parser::{Parser, ParserError};
@@ -135,15 +134,6 @@ impl Dialect for PostgreSqlDialect {
         }
     }
 
-    fn parse_statement(&self, parser: &mut Parser) -> Option<Result<Statement, ParserError>> {
-        if parser.parse_keyword(Keyword::CREATE) {
-            parser.prev_token(); // unconsume the CREATE in case we don't end up parsing anything
-            parse_create(parser)
-        } else {
-            None
-        }
-    }
-
     fn supports_filter_during_aggregation(&self) -> bool {
         true
     }
@@ -259,37 +249,3 @@ impl Dialect for PostgreSqlDialect {
         true
     }
 }
-
-pub fn parse_create(parser: &mut Parser) -> Option<Result<Statement, ParserError>> {
-    let name = parser.maybe_parse(|parser| -> Result<ObjectName, ParserError> {
-        parser.expect_keyword_is(Keyword::CREATE)?;
-        parser.expect_keyword_is(Keyword::TYPE)?;
-        let name = parser.parse_object_name(false)?;
-        parser.expect_keyword_is(Keyword::AS)?;
-        parser.expect_keyword_is(Keyword::ENUM)?;
-        Ok(name)
-    });
-
-    match name {
-        Ok(name) => name.map(|name| parse_create_type_as_enum(parser, name)),
-        Err(e) => Some(Err(e)),
-    }
-}
-
-// https://www.postgresql.org/docs/current/sql-createtype.html
-pub fn parse_create_type_as_enum(
-    parser: &mut Parser,
-    name: ObjectName,
-) -> Result<Statement, ParserError> {
-    if !parser.consume_token(&Token::LParen) {
-        return parser.expected("'(' after CREATE TYPE AS ENUM", parser.peek_token());
-    }
-
-    let labels = parser.parse_comma_separated0(|p| p.parse_identifier(), Token::RParen)?;
-    parser.expect_token(&Token::RParen)?;
-
-    Ok(Statement::CreateType {
-        name,
-        representation: UserDefinedTypeRepresentation::Enum { labels },
-    })
-}

src/parser/mod.rs

@@ -14222,6 +14222,10 @@ impl<'a> Parser<'a> {
         let name = self.parse_object_name(false)?;
         self.expect_keyword_is(Keyword::AS)?;
 
+        if self.parse_keyword(Keyword::ENUM) {
+            return self.parse_create_type_enum(name);
+        }
+
         let mut attributes = vec![];
         if !self.consume_token(&Token::LParen) || self.consume_token(&Token::RParen) {
             return Ok(Statement::CreateType {
@@ -14258,6 +14262,20 @@ impl<'a> Parser<'a> {
         })
     }
 
+    /// Parse remainder of `CREATE TYPE AS ENUM` statement (see [Statement::CreateType] and [Self::parse_create_type])
+    ///
+    /// See [PostgreSQL](https://www.postgresql.org/docs/current/sql-createtype.html)
+    pub fn parse_create_type_enum(&mut self, name: ObjectName) -> Result<Statement, ParserError> {
+        self.expect_token(&Token::LParen)?;
+        let labels = self.parse_comma_separated0(|p| p.parse_identifier(), Token::RParen)?;
+        self.expect_token(&Token::RParen)?;
+
+        Ok(Statement::CreateType {
+            name,
+            representation: UserDefinedTypeRepresentation::Enum { labels },
+        })
+    }
+
     fn parse_parenthesized_identifiers(&mut self) -> Result<Vec<Ident>, ParserError> {
         self.expect_token(&Token::LParen)?;
         let partitions = self.parse_comma_separated(|p| p.parse_identifier())?;

tests/sqlparser_postgres.rs

@@ -5293,15 +5293,8 @@ fn arrow_cast_precedence() {
 
 #[test]
 fn parse_create_type_as_enum() {
-    let statement = pg().one_statement_parses_to(
-        r#"CREATE TYPE public.my_type AS ENUM (
-            'label1',
-            'label2',
-            'label3',
-            'label4'
-        );"#,
-        "CREATE TYPE public.my_type AS ENUM ('label1', 'label2', 'label3', 'label4')",
-    );
+    let sql = "CREATE TYPE public.my_type AS ENUM ('label1', 'label2', 'label3', 'label4')";
+    let statement = pg_and_generic().verified_stmt(sql);
     match statement {
         Statement::CreateType {
             name,
@@ -5316,7 +5309,7 @@ fn parse_create_type_as_enum() {
                 labels
             );
         }
-        _ => unreachable!(),
+        _ => unreachable!("{:?} should parse to Statement::CreateType", sql),
     }
 }