diff --git a/src/ast/data_type.rs b/src/ast/data_type.rs
index c994645ba..2f844d50e 100644
--- a/src/ast/data_type.rs
+++ b/src/ast/data_type.rs
@@ -33,8 +33,11 @@ pub enum DataType {
     Nvarchar(Option<u64>),
     /// Uuid type
     Uuid,
-    /// Large character object e.g. CLOB(1000)
-    Clob(u64),
+    /// Large character object with optional length e.g. CLOB, CLOB(1000), [standard], [Oracle]
+    ///
+    /// [standard]: https://jakewheat.github.io/sql-overview/sql-2016-foundation-grammar.html#character-large-object-type
+    /// [Oracle]: https://docs.oracle.com/javadb/10.10.1.2/ref/rrefclob.html
+    Clob(Option<u64>),
     /// Fixed-length binary type with optional length e.g.  [standard], [MS SQL Server]
     ///
     /// [standard]: https://jakewheat.github.io/sql-overview/sql-2016-foundation-grammar.html#binary-string-type
@@ -45,8 +48,11 @@ pub enum DataType {
     /// [standard]: https://jakewheat.github.io/sql-overview/sql-2016-foundation-grammar.html#binary-string-type
     /// [MS SQL Server]: https://learn.microsoft.com/pt-br/sql/t-sql/data-types/binary-and-varbinary-transact-sql?view=sql-server-ver16
     Varbinary(Option<u64>),
-    /// Large binary object e.g. BLOB(1000)
-    Blob(u64),
+    /// Large binary object with optional length e.g. BLOB, BLOB(1000), [standard], [Oracle]
+    ///
+    /// [standard]: https://jakewheat.github.io/sql-overview/sql-2016-foundation-grammar.html#binary-large-object-string-type
+    /// [Oracle]: https://docs.oracle.com/javadb/10.8.3.0/ref/rrefblob.html
+    Blob(Option<u64>),
     /// Decimal type with optional precision and scale e.g. DECIMAL(10,2)
     Decimal(Option<u64>, Option<u64>),
     /// Floating point with optional precision e.g. FLOAT(8)
@@ -131,12 +137,12 @@ impl fmt::Display for DataType {
                 format_type_with_optional_length(f, "NVARCHAR", size, false)
             }
             DataType::Uuid => write!(f, "UUID"),
-            DataType::Clob(size) => write!(f, "CLOB({})", size),
+            DataType::Clob(size) => format_type_with_optional_length(f, "CLOB", size, false),
             DataType::Binary(size) => format_type_with_optional_length(f, "BINARY", size, false),
             DataType::Varbinary(size) => {
                 format_type_with_optional_length(f, "VARBINARY", size, false)
             }
-            DataType::Blob(size) => write!(f, "BLOB({})", size),
+            DataType::Blob(size) => format_type_with_optional_length(f, "BLOB", size, false),
             DataType::Decimal(precision, scale) => {
                 if let Some(scale) = scale {
                     write!(f, "NUMERIC({},{})", precision.unwrap(), scale)
diff --git a/src/parser.rs b/src/parser.rs
index 09419cc29..9ac5f89c6 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -3403,10 +3403,10 @@ impl<'a> Parser<'a> {
                         Ok(DataType::Char(self.parse_optional_precision()?))
                     }
                 }
-                Keyword::CLOB => Ok(DataType::Clob(self.parse_precision()?)),
+                Keyword::CLOB => Ok(DataType::Clob(self.parse_optional_precision()?)),
                 Keyword::BINARY => Ok(DataType::Binary(self.parse_optional_precision()?)),
                 Keyword::VARBINARY => Ok(DataType::Varbinary(self.parse_optional_precision()?)),
-                Keyword::BLOB => Ok(DataType::Blob(self.parse_precision()?)),
+                Keyword::BLOB => Ok(DataType::Blob(self.parse_optional_precision()?)),
                 Keyword::UUID => Ok(DataType::Uuid),
                 Keyword::DATE => Ok(DataType::Date),
                 Keyword::DATETIME => Ok(DataType::Datetime),
@@ -5258,6 +5258,10 @@ mod tests {
     // TODO add tests for all data types? https://github.com/sqlparser-rs/sqlparser-rs/issues/2
     #[test]
     fn test_parse_data_type() {
+        test_parse_data_type("BLOB", "BLOB");
+        test_parse_data_type("BLOB(50)", "BLOB(50)");
+        test_parse_data_type("CLOB", "CLOB");
+        test_parse_data_type("CLOB(50)", "CLOB(50)");
         test_parse_data_type("DOUBLE PRECISION", "DOUBLE PRECISION");
         test_parse_data_type("DOUBLE", "DOUBLE");
         test_parse_data_type("VARBINARY", "VARBINARY");
diff --git a/tests/sqlparser_common.rs b/tests/sqlparser_common.rs
index 391eff134..956a62297 100644
--- a/tests/sqlparser_common.rs
+++ b/tests/sqlparser_common.rs
@@ -1655,12 +1655,22 @@ fn parse_cast() {
         expr_from_projection(only(&select.projection))
     );
 
+    let sql = "SELECT CAST(id AS CLOB) FROM customer";
+    let select = verified_only_select(sql);
+    assert_eq!(
+        &Expr::Cast {
+            expr: Box::new(Expr::Identifier(Ident::new("id"))),
+            data_type: DataType::Clob(None)
+        },
+        expr_from_projection(only(&select.projection))
+    );
+
     let sql = "SELECT CAST(id AS CLOB(50)) FROM customer";
     let select = verified_only_select(sql);
     assert_eq!(
         &Expr::Cast {
             expr: Box::new(Expr::Identifier(Ident::new("id"))),
-            data_type: DataType::Clob(50)
+            data_type: DataType::Clob(Some(50))
         },
         expr_from_projection(only(&select.projection))
     );
@@ -1685,12 +1695,22 @@ fn parse_cast() {
         expr_from_projection(only(&select.projection))
     );
 
+    let sql = "SELECT CAST(id AS BLOB) FROM customer";
+    let select = verified_only_select(sql);
+    assert_eq!(
+        &Expr::Cast {
+            expr: Box::new(Expr::Identifier(Ident::new("id"))),
+            data_type: DataType::Blob(None)
+        },
+        expr_from_projection(only(&select.projection))
+    );
+
     let sql = "SELECT CAST(id AS BLOB(50)) FROM customer";
     let select = verified_only_select(sql);
     assert_eq!(
         &Expr::Cast {
             expr: Box::new(Expr::Identifier(Ident::new("id"))),
-            data_type: DataType::Blob(50)
+            data_type: DataType::Blob(Some(50))
         },
         expr_from_projection(only(&select.projection))
     );