diff --git a/src/ast/query.rs b/src/ast/query.rs index 9bcdc2e74..fc5ad27cc 100644 --- a/src/ast/query.rs +++ b/src/ast/query.rs @@ -1873,13 +1873,19 @@ impl fmt::Display for TableAliasColumnDef { #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))] #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))] pub enum TableVersion { + /// When the table version is defined using `FOR SYSTEM_TIME AS OF`. + /// For example: `SELECT * FROM tbl FOR SYSTEM_TIME AS OF TIMESTAMP_SUB(CURRENT_TIMESTAMP(), INTERVAL 1 HOUR)` ForSystemTimeAsOf(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), } impl Display for TableVersion { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { match self { TableVersion::ForSystemTimeAsOf(e) => write!(f, " FOR SYSTEM_TIME AS OF {e}")?, + TableVersion::Function(func) => write!(f, " {func}")?, } Ok(()) } diff --git a/src/dialect/bigquery.rs b/src/dialect/bigquery.rs index 66d7d2061..e92169a35 100644 --- a/src/dialect/bigquery.rs +++ b/src/dialect/bigquery.rs @@ -77,4 +77,9 @@ impl Dialect for BigQueryDialect { fn supports_struct_literal(&self) -> bool { true } + + // See + fn supports_timestamp_versioning(&self) -> bool { + true + } } diff --git a/src/dialect/mod.rs b/src/dialect/mod.rs index c69253b76..119bb3cf7 100644 --- a/src/dialect/mod.rs +++ b/src/dialect/mod.rs @@ -834,6 +834,12 @@ pub trait Dialect: Debug + Any { fn is_table_factor_alias(&self, explicit: bool, kw: &Keyword, _parser: &mut Parser) -> bool { explicit || !keywords::RESERVED_FOR_TABLE_ALIAS.contains(kw) } + + /// Returns true if this dialect supports querying historical table data + /// by specifying which version of the data to query. + fn supports_timestamp_versioning(&self) -> bool { + false + } } /// This represents the operators for which precedence must be defined diff --git a/src/dialect/mssql.rs b/src/dialect/mssql.rs index 67a648944..7d8611cb0 100644 --- a/src/dialect/mssql.rs +++ b/src/dialect/mssql.rs @@ -90,4 +90,9 @@ impl Dialect for MsSqlDialect { fn supports_set_stmt_without_operator(&self) -> bool { true } + + /// See: + fn supports_timestamp_versioning(&self) -> bool { + true + } } diff --git a/src/dialect/snowflake.rs b/src/dialect/snowflake.rs index f6e9c9eba..78237acd0 100644 --- a/src/dialect/snowflake.rs +++ b/src/dialect/snowflake.rs @@ -296,6 +296,11 @@ impl Dialect for SnowflakeDialect { _ => true, } } + + /// See: + fn supports_timestamp_versioning(&self) -> bool { + true + } } fn parse_file_staging_command(kw: Keyword, parser: &mut Parser) -> Result { diff --git a/src/parser/mod.rs b/src/parser/mod.rs index 5cacfda98..d8c548a7f 100644 --- a/src/parser/mod.rs +++ b/src/parser/mod.rs @@ -11181,7 +11181,7 @@ impl<'a> Parser<'a> { }; // Parse potential version qualifier - let version = self.parse_table_version()?; + let version = self.maybe_parse_table_version()?; // Postgres, MSSQL, ClickHouse: table-valued functions: let args = if self.consume_token(&Token::LParen) { @@ -11612,18 +11612,20 @@ impl<'a> Parser<'a> { } } - /// Parse a given table version specifier. - /// - /// For now it only supports timestamp versioning for BigQuery and MSSQL dialects. - pub fn parse_table_version(&mut self) -> Result, ParserError> { - if dialect_of!(self is BigQueryDialect | MsSqlDialect) - && self.parse_keywords(&[Keyword::FOR, Keyword::SYSTEM_TIME, Keyword::AS, Keyword::OF]) - { - let expr = self.parse_expr()?; - Ok(Some(TableVersion::ForSystemTimeAsOf(expr))) - } else { - Ok(None) + /// Parses a the timestamp version specifier (i.e. query historical data) + pub fn maybe_parse_table_version(&mut self) -> Result, ParserError> { + if self.dialect.supports_timestamp_versioning() { + if self.parse_keywords(&[Keyword::FOR, Keyword::SYSTEM_TIME, Keyword::AS, Keyword::OF]) + { + let expr = self.parse_expr()?; + return Ok(Some(TableVersion::ForSystemTimeAsOf(expr))); + } else if self.peek_keyword(Keyword::AT) || self.peek_keyword(Keyword::BEFORE) { + let func_name = self.parse_object_name(true)?; + let func = self.parse_function(func_name)?; + return Ok(Some(TableVersion::Function(func))); + } } + Ok(None) } /// Parses MySQL's JSON_TABLE column definition. diff --git a/tests/sqlparser_snowflake.rs b/tests/sqlparser_snowflake.rs index fe6439b36..0c4bdf149 100644 --- a/tests/sqlparser_snowflake.rs +++ b/tests/sqlparser_snowflake.rs @@ -3051,3 +3051,10 @@ fn test_sql_keywords_as_select_item_aliases() { .is_err()); } } + +#[test] +fn test_timetravel_at_before() { + snowflake().verified_only_select("SELECT * FROM tbl AT(TIMESTAMP => '2024-12-15 00:00:00')"); + snowflake() + .verified_only_select("SELECT * FROM tbl BEFORE(TIMESTAMP => '2024-12-15 00:00:00')"); +}