Merge pull request #22 from Embucket/snowflake-structured-object

Snowflake: parse structured OBJECT types

Author: osipovartem

src/ast/data_type.rs

@@ -451,6 +451,10 @@ pub enum DataType {
     ///
     /// [ClickHouse]: https://clickhouse.com/docs/en/sql-reference/data-types/nested-data-structures/nested
     Nested(Vec<ColumnDef>),
+    /// Structured object type, see [Snowflake].
+    ///
+    /// [Snowflake]: https://docs.snowflake.com/en/sql-reference/data-types-structured#structured-object-types
+    Object(Vec<ColumnDef>),
     /// Enum type.
     Enum(Vec<EnumMember>, Option<u8>),
     /// Set type.
@@ -794,6 +798,9 @@ impl fmt::Display for DataType {
             DataType::Nested(fields) => {
                 write!(f, "Nested({})", display_comma_separated(fields))
             }
+            DataType::Object(fields) => {
+                write!(f, "OBJECT({})", display_comma_separated(fields))
+            }
             DataType::Unspecified => Ok(()),
             DataType::Trigger => write!(f, "TRIGGER"),
             DataType::AnyType => write!(f, "ANY TYPE"),

src/dialect/mod.rs

@@ -1076,6 +1076,16 @@ pub trait Dialect: Debug + Any {
         false
     }
 
+    /// Returns true if this dialect supports structured `OBJECT` types.
+    ///
+    /// Example:
+    /// ```sql
+    /// CREATE TABLE t (o OBJECT(city VARCHAR, zip NUMBER NOT NULL));
+    /// ```
+    fn supports_structured_object_type(&self) -> bool {
+        false
+    }
+
     /// Returns true if this dialect supports extra parentheses around
     /// lone table names or derived tables in the `FROM` clause.
     ///

src/dialect/snowflake.rs

@@ -242,6 +242,11 @@ impl Dialect for SnowflakeDialect {
         true
     }
 
+    /// See [doc](https://docs.snowflake.com/en/sql-reference/data-types-structured#structured-object-types)
+    fn supports_structured_object_type(&self) -> bool {
+        true
+    }
+
     /// See [doc](https://docs.snowflake.com/en/sql-reference/constructs/from)
     fn supports_parens_around_table_factor(&self) -> bool {
         true

src/parser/mod.rs

@@ -12646,6 +12646,12 @@ impl<'a> Parser<'a> {
                         ))))
                     }
                 }
+                Keyword::OBJECT
+                    if self.dialect.supports_structured_object_type()
+                        && self.peek_token_ref().token == Token::LParen =>
+                {
+                    Ok(DataType::Object(self.parse_structured_object_type_def()?))
+                }
                 Keyword::STRUCT if dialect_is!(dialect is DuckDbDialect) => {
                     self.prev_token();
                     let field_defs = self.parse_duckdb_struct_type_def()?;
@@ -13847,6 +13853,29 @@ impl<'a> Parser<'a> {
         }
     }
 
+    fn parse_structured_object_type_def(&mut self) -> Result<Vec<ColumnDef>, ParserError> {
+        self.expect_token(&Token::LParen)?;
+        let fields = self.parse_comma_separated(|parser| {
+            let name = parser.parse_identifier()?;
+            let data_type = parser.parse_data_type()?;
+            let options = if parser.parse_keywords(&[Keyword::NOT, Keyword::NULL]) {
+                vec![ColumnOptionDef {
+                    name: None,
+                    option: ColumnOption::NotNull,
+                }]
+            } else {
+                vec![]
+            };
+            Ok(ColumnDef {
+                name,
+                data_type,
+                options,
+            })
+        })?;
+        self.expect_token(&Token::RParen)?;
+        Ok(fields)
+    }
+
     /// Parse a parenthesized sub data type
     fn parse_sub_type<F>(&mut self, parent_type: F) -> Result<DataType, ParserError>
     where

tests/sqlparser_snowflake.rs

@@ -5202,3 +5202,40 @@ fn test_external_volume() {
         "Unexpected error: {err}"
     );
 }
+
+#[test]
+fn test_structured_object_type() {
+    snowflake().one_statement_parses_to(
+        "SELECT payload::OBJECT(tags ARRAY(VARCHAR), address OBJECT(city VARCHAR NOT NULL)) FROM t",
+        "SELECT payload::OBJECT(tags Array(VARCHAR), address OBJECT(city VARCHAR NOT NULL)) FROM t",
+    );
+
+    let select = snowflake().verified_only_select(
+        "SELECT CAST(payload AS OBJECT(city VARCHAR, zip NUMBER NOT NULL)) FROM t",
+    );
+    let Expr::Cast { data_type, .. } = expr_from_projection(only(&select.projection)) else {
+        unreachable!();
+    };
+    let DataType::Object(fields) = data_type else {
+        unreachable!();
+    };
+    assert_eq!(fields.len(), 2);
+    assert_eq!(fields[0].name, Ident::new("city"));
+    assert!(fields[0].options.is_empty());
+    assert_eq!(fields[1].name, Ident::new("zip"));
+    assert_eq!(fields[1].options.len(), 1);
+    assert_eq!(fields[1].options[0].option, ColumnOption::NotNull);
+
+    snowflake().verified_stmt("CREATE TABLE t (o OBJECT)");
+}
+
+#[test]
+fn test_structured_object_type_errors() {
+    for sql in [
+        "CREATE TABLE t (o OBJECT(VARCHAR))",
+        "CREATE TABLE t (o OBJECT(city VARCHAR NULL))",
+        "CREATE TABLE t (o OBJECT(city VARCHAR)",
+    ] {
+        assert!(snowflake().parse_sql_statements(sql).is_err(), "{sql}");
+    }
+}