version as of time-travel support

Author: JamesVorder

src/ast/query.rs

@@ -2245,6 +2245,10 @@ pub enum TableVersion {
     /// Databricks supports this syntax.
     /// For example: `SELECT * FROM tbl TIMESTAMP AS OF CURRENT_TIMESTAMP() - INTERVAL 1 HOUR`
     TimestampAsOf(Expr),
+    /// When the table version is defined using `VERSION AS OF`.
+    /// Databricks supports this syntax.
+    /// For example: `SELECT * FROM tbl VERSION AS OF 2`
+    VersionAsOf(Expr),
     /// When the table version is defined using a function.
     /// For example: `SELECT * FROM tbl AT(TIMESTAMP => '2020-08-14 09:30:00')`
     Function(Expr),
@@ -2255,6 +2259,7 @@ impl Display for TableVersion {
         match self {
             TableVersion::ForSystemTimeAsOf(e) => write!(f, "FOR SYSTEM_TIME AS OF {e}")?,
             TableVersion::TimestampAsOf(e) => write!(f, "TIMESTAMP AS OF {e}")?,
+            TableVersion::VersionAsOf(e) => write!(f, "VERSION AS OF {e}")?,
             TableVersion::Function(func) => write!(f, "{func}")?,
         }
         Ok(())

src/parser/mod.rs

@@ -15496,6 +15496,9 @@ impl<'a> Parser<'a> {
             } else if self.parse_keywords(&[Keyword::TIMESTAMP, Keyword::AS, Keyword::OF]) {
                 let expr = self.parse_expr()?;
                 return Ok(Some(TableVersion::TimestampAsOf(expr)));
+            } else if self.parse_keywords(&[Keyword::VERSION, Keyword::AS, Keyword::OF]) {
+                let expr = Expr::Value(self.parse_number_value()?);
+                return Ok(Some(TableVersion::VersionAsOf(expr)));
             }
         }
         Ok(None)

tests/sqlparser_databricks.rs

@@ -376,7 +376,15 @@ fn parse_table_time_travel() {
         "SELECT 1 FROM t1 TIMESTAMP AS OF CURRENT_TIMESTAMP() - INTERVAL 12 HOURS",
     );
 
+    all_dialects_where(|d| d.supports_timestamp_versioning()).verified_only_select(
+        "SELECT 1 FROM t1 VERSION AS OF 1",
+    );
+
     assert!(databricks()
         .parse_sql_statements("SELECT 1 FROM t1 FOR TIMESTAMP AS OF 'some_timestamp'")
         .is_err());
+
+    assert!(all_dialects_where(|d| d.supports_timestamp_versioning()).parse_sql_statements(
+        "SELECT 1 FROM t1 VERSION AS OF 1 - 2",
+    ).is_err())
 }