Add support for XMLTABLE (#1817)

src/ast/mod.rs

@@ -81,7 +81,8 @@ pub use self::query::{
     TableSampleBucket, TableSampleKind, TableSampleMethod, TableSampleModifier,
     TableSampleQuantity, TableSampleSeed, TableSampleSeedModifier, TableSampleUnit, TableVersion,
     TableWithJoins, Top, TopQuantity, UpdateTableFromKind, ValueTableMode, Values,
-    WildcardAdditionalOptions, With, WithFill,
+    WildcardAdditionalOptions, With, WithFill, XmlNamespaceDefinition, XmlPassingArgument,
+    XmlPassingClause, XmlTableColumn, XmlTableColumnOption,
 };
 
 pub use self::trigger::{

src/ast/query.rs

@@ -1271,6 +1271,37 @@ pub enum TableFactor {
         symbols: Vec<SymbolDefinition>,
         alias: Option<TableAlias>,
     },
+    /// The `XMLTABLE` table-valued function.
+    /// Part of the SQL standard, supported by PostgreSQL, Oracle, and DB2.
+    ///
+    /// <https://www.postgresql.org/docs/15/functions-xml.html#FUNCTIONS-XML-PROCESSING>
+    ///
+    /// ```sql
+    /// SELECT xmltable.*
+    /// FROM xmldata,
+    /// XMLTABLE('//ROWS/ROW'
+    ///     PASSING data
+    ///     COLUMNS id int PATH '@id',
+    ///     ordinality FOR ORDINALITY,
+    ///     "COUNTRY_NAME" text,
+    ///     country_id text PATH 'COUNTRY_ID',
+    ///     size_sq_km float PATH 'SIZE[@unit = "sq_km"]',
+    ///     size_other text PATH 'concat(SIZE[@unit!="sq_km"], " ", SIZE[@unit!="sq_km"]/@unit)',
+    ///     premier_name text PATH 'PREMIER_NAME' DEFAULT 'not specified'
+    /// );
+    /// ````
+    XmlTable {
+        /// Optional XMLNAMESPACES clause (empty if not present)
+        namespaces: Vec<XmlNamespaceDefinition>,
+        /// The row-generating XPath expression.
+        row_expression: Expr,
+        /// The PASSING clause specifying the document expression.
+        passing: XmlPassingClause,
+        /// The columns to be extracted from each generated row.
+        columns: Vec<XmlTableColumn>,
+        /// The alias for the table.
+        alias: Option<TableAlias>,
+    },
 }
 
 /// The table sample modifier options
@@ -1936,6 +1967,31 @@ impl fmt::Display for TableFactor {
                 }
                 Ok(())
             }
+            TableFactor::XmlTable {
+                row_expression,
+                passing,
+                columns,
+                alias,
+                namespaces,
+            } => {
+                write!(f, "XMLTABLE(")?;
+                if !namespaces.is_empty() {
+                    write!(
+                        f,
+                        "XMLNAMESPACES({}), ",
+                        display_comma_separated(namespaces)
+                    )?;
+                }
+                write!(
+                    f,
+                    "{row_expression}{passing} COLUMNS {columns})",
+                    columns = display_comma_separated(columns)
+                )?;
+                if let Some(alias) = alias {
+                    write!(f, " AS {alias}")?;
+                }
+                Ok(())
+            }
         }
     }
 }
@@ -3082,3 +3138,133 @@ pub enum UpdateTableFromKind {
     /// For Example: `UPDATE SET t1.name='aaa' FROM t1`
     AfterSet(Vec<TableWithJoins>),
 }
+
+/// Defines the options for an XmlTable column: Named or ForOrdinality
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub enum XmlTableColumnOption {
+    /// A named column with a type, optional path, and default value.
+    NamedInfo {
+        /// The type of the column to be extracted.
+        r#type: DataType,
+        /// The path to the column to be extracted. If None, defaults to the column name.
+        path: Option<Expr>,
+        /// Default value if path does not match
+        default: Option<Expr>,
+        /// Whether the column is nullable (NULL=true, NOT NULL=false)
+        nullable: bool,
+    },
+    /// The FOR ORDINALITY marker
+    ForOrdinality,
+}
+
+/// A single column definition in XMLTABLE
+///
+/// ```sql
+/// COLUMNS
+///     id int PATH '@id',
+///     ordinality FOR ORDINALITY,
+///     "COUNTRY_NAME" text,
+///     country_id text PATH 'COUNTRY_ID',
+///     size_sq_km float PATH 'SIZE[@unit = "sq_km"]',
+///     size_other text PATH 'concat(SIZE[@unit!="sq_km"], " ", SIZE[@unit!="sq_km"]/@unit)',
+///     premier_name text PATH 'PREMIER_NAME' DEFAULT 'not specified'
+/// ```
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct XmlTableColumn {
+    /// The name of the column.
+    pub name: Ident,
+    /// Column options: type/path/default or FOR ORDINALITY
+    pub option: XmlTableColumnOption,
+}
+
+impl fmt::Display for XmlTableColumn {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.name)?;
+        match &self.option {
+            XmlTableColumnOption::NamedInfo {
+                r#type,
+                path,
+                default,
+                nullable,
+            } => {
+                write!(f, " {}", r#type)?;
+                if let Some(p) = path {
+                    write!(f, " PATH {}", p)?;
+                }
+                if let Some(d) = default {
+                    write!(f, " DEFAULT {}", d)?;
+                }
+                if !*nullable {
+                    write!(f, " NOT NULL")?;
+                }
+                Ok(())
+            }
+            XmlTableColumnOption::ForOrdinality => {
+                write!(f, " FOR ORDINALITY")
+            }
+        }
+    }
+}
+
+/// Argument passed in the XMLTABLE PASSING clause
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct XmlPassingArgument {
+    pub expr: Expr,
+    pub alias: Option<Ident>,
+    pub by_value: bool, // True if BY VALUE is specified
+}
+
+impl fmt::Display for XmlPassingArgument {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if self.by_value {
+            write!(f, "BY VALUE ")?;
+        }
+        write!(f, "{}", self.expr)?;
+        if let Some(alias) = &self.alias {
+            write!(f, " AS {}", alias)?;
+        }
+        Ok(())
+    }
+}
+
+/// The PASSING clause for XMLTABLE
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct XmlPassingClause {
+    pub arguments: Vec<XmlPassingArgument>,
+}
+
+impl fmt::Display for XmlPassingClause {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if !self.arguments.is_empty() {
+            write!(f, " PASSING {}", display_comma_separated(&self.arguments))?;
+        }
+        Ok(())
+    }
+}
+
+/// Represents a single XML namespace definition in the XMLNAMESPACES clause.
+///
+/// `namespace_uri AS namespace_name`
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct XmlNamespaceDefinition {
+    /// The namespace URI (a text expression).
+    pub uri: Expr,
+    /// The alias for the namespace (a simple identifier).
+    pub name: Ident,
+}
+
+impl fmt::Display for XmlNamespaceDefinition {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{} AS {}", self.uri, self.name)
+    }
+}

src/ast/spans.rs

@@ -1909,6 +1909,7 @@ impl Spanned for TableFactor {
                     .chain(alias.as_ref().map(|alias| alias.span())),
             ),
             TableFactor::JsonTable { .. } => Span::empty(),
+            TableFactor::XmlTable { .. } => Span::empty(),
             TableFactor::Pivot {
                 table,
                 aggregate_functions,

src/keywords.rs

@@ -654,6 +654,7 @@ define_keywords!(
     PARTITION,
     PARTITIONED,
     PARTITIONS,
+    PASSING,
     PASSWORD,
     PAST,
     PATH,
@@ -989,6 +990,8 @@ define_keywords!(
     WORK,
     WRITE,
     XML,
+    XMLNAMESPACES,
+    XMLTABLE,
     XOR,
     YEAR,
     YEARS,

src/parser/mod.rs

@@ -11992,6 +11992,7 @@ impl<'a> Parser<'a> {
                         | TableFactor::Function { alias, .. }
                         | TableFactor::UNNEST { alias, .. }
                         | TableFactor::JsonTable { alias, .. }
+                        | TableFactor::XmlTable { alias, .. }
                         | TableFactor::OpenJsonTable { alias, .. }
                         | TableFactor::TableFunction { alias, .. }
                         | TableFactor::Pivot { alias, .. }
@@ -12107,6 +12108,9 @@ impl<'a> Parser<'a> {
         } else if self.parse_keyword_with_tokens(Keyword::OPENJSON, &[Token::LParen]) {
             self.prev_token();
             self.parse_open_json_table_factor()
+        } else if self.parse_keyword_with_tokens(Keyword::XMLTABLE, &[Token::LParen]) {
+            self.prev_token();
+            self.parse_xml_table_factor()
         } else {
             let name = self.parse_object_name(true)?;
 
@@ -12339,6 +12343,99 @@ impl<'a> Parser<'a> {
         })
     }
 
+    fn parse_xml_table_factor(&mut self) -> Result<TableFactor, ParserError> {
+        self.expect_token(&Token::LParen)?;
+        let namespaces = if self.parse_keyword(Keyword::XMLNAMESPACES) {
+            self.expect_token(&Token::LParen)?;
+            let namespaces = self.parse_comma_separated(Parser::parse_xml_namespace_definition)?;
+            self.expect_token(&Token::RParen)?;
+            self.expect_token(&Token::Comma)?;
+            namespaces
+        } else {
+            vec![]
+        };
+        let row_expression = self.parse_expr()?;
+        let passing = self.parse_xml_passing_clause()?;
+        self.expect_keyword_is(Keyword::COLUMNS)?;
+        let columns = self.parse_comma_separated(Parser::parse_xml_table_column)?;
+        self.expect_token(&Token::RParen)?;
+        let alias = self.maybe_parse_table_alias()?;
+        Ok(TableFactor::XmlTable {
+            namespaces,
+            row_expression,
+            passing,
+            columns,
+            alias,
+        })
+    }
+
+    fn parse_xml_namespace_definition(&mut self) -> Result<XmlNamespaceDefinition, ParserError> {
+        let uri = self.parse_expr()?;
+        self.expect_keyword_is(Keyword::AS)?;
+        let name = self.parse_identifier()?;
+        Ok(XmlNamespaceDefinition { uri, name })
+    }
+
+    fn parse_xml_table_column(&mut self) -> Result<XmlTableColumn, ParserError> {
+        let name = self.parse_identifier()?;
+
+        let option = if self.parse_keyword(Keyword::FOR) {
+            self.expect_keyword(Keyword::ORDINALITY)?;
+            XmlTableColumnOption::ForOrdinality
+        } else {
+            let r#type = self.parse_data_type()?;
+            let mut path = None;
+            let mut default = None;
+
+            if self.parse_keyword(Keyword::PATH) {
+                path = Some(self.parse_expr()?);
+            }
+
+            if self.parse_keyword(Keyword::DEFAULT) {
+                default = Some(self.parse_expr()?);
+            }
+
+            let not_null = self.parse_keywords(&[Keyword::NOT, Keyword::NULL]);
+            if !not_null {
+                // NULL is the default but can be specified explicitly
+                let _ = self.parse_keyword(Keyword::NULL);
+            }
+
+            XmlTableColumnOption::NamedInfo {
+                r#type,
+                path,
+                default,
+                nullable: !not_null,
+            }
+        };
+        Ok(XmlTableColumn { name, option })
+    }
+
+    fn parse_xml_passing_clause(&mut self) -> Result<XmlPassingClause, ParserError> {
+        let mut arguments = vec![];
+        if self.parse_keyword(Keyword::PASSING) {
+            loop {
+                let by_value =
+                    self.parse_keyword(Keyword::BY) && self.expect_keyword(Keyword::VALUE).is_ok();
+                let expr = self.parse_expr()?;
+                let alias = if self.parse_keyword(Keyword::AS) {
+                    Some(self.parse_identifier()?)
+                } else {
+                    None
+                };
+                arguments.push(XmlPassingArgument {
+                    expr,
+                    alias,
+                    by_value,
+                });
+                if !self.consume_token(&Token::Comma) {
+                    break;
+                }
+            }
+        }
+        Ok(XmlPassingClause { arguments })
+    }
+
     fn parse_match_recognize(&mut self, table: TableFactor) -> Result<TableFactor, ParserError> {
         self.expect_token(&Token::LParen)?;
 

tests/sqlparser_common.rs

@@ -11741,6 +11741,44 @@ fn test_group_by_grouping_sets() {
     );
 }
 
+#[test]
+fn test_xmltable() {
+    all_dialects()
+        .verified_only_select("SELECT * FROM XMLTABLE('/root' PASSING data COLUMNS element TEXT)");
+
+    // Minimal meaningful working example: returns a single row with a single column named y containing the value z
+    all_dialects().verified_only_select(
+        "SELECT y FROM XMLTABLE('/X' PASSING '<X><y>z</y></X>' COLUMNS y TEXT)",
+    );
+
+    // Test using subqueries
+    all_dialects().verified_only_select("SELECT y FROM XMLTABLE((SELECT '/X') PASSING (SELECT CAST('<X><y>z</y></X>' AS xml)) COLUMNS y TEXT PATH (SELECT 'y'))");
+
+    // NOT NULL
+    all_dialects().verified_only_select(
+        "SELECT y FROM XMLTABLE('/X' PASSING '<X></X>' COLUMNS y TEXT NOT NULL)",
+    );
+
+    all_dialects().verified_only_select("SELECT * FROM XMLTABLE('/root/row' PASSING xmldata COLUMNS id INT PATH '@id', name TEXT PATH 'name/text()', value FLOAT PATH 'value')");
+
+    all_dialects().verified_only_select("SELECT * FROM XMLTABLE('//ROWS/ROW' PASSING data COLUMNS row_num FOR ORDINALITY, id INT PATH '@id', name TEXT PATH 'NAME' DEFAULT 'unnamed')");
+
+    // Example from https://www.postgresql.org/docs/15/functions-xml.html#FUNCTIONS-XML-PROCESSING
+    all_dialects().verified_only_select(
+        "SELECT xmltable.* FROM xmldata, XMLTABLE('//ROWS/ROW' PASSING data COLUMNS id INT PATH '@id', ordinality FOR ORDINALITY, \"COUNTRY_NAME\" TEXT, country_id TEXT PATH 'COUNTRY_ID', size_sq_km FLOAT PATH 'SIZE[@unit = \"sq_km\"]', size_other TEXT PATH 'concat(SIZE[@unit!=\"sq_km\"], \" \", SIZE[@unit!=\"sq_km\"]/@unit)', premier_name TEXT PATH 'PREMIER_NAME' DEFAULT 'not specified')"
+    );
+
+    // Example from DB2 docs without explicit PASSING clause: https://www.ibm.com/docs/en/db2/12.1.0?topic=xquery-simple-column-name-passing-xmlexists-xmlquery-xmltable
+    all_dialects().verified_only_select(
+        "SELECT X.* FROM T1, XMLTABLE('$CUSTLIST/customers/customerinfo' COLUMNS \"Cid\" BIGINT PATH '@Cid', \"Info\" XML PATH 'document{.}', \"History\" XML PATH 'NULL') AS X"
+    );
+
+    // Example from PostgreSQL with XMLNAMESPACES
+    all_dialects().verified_only_select(
+        "SELECT xmltable.* FROM XMLTABLE(XMLNAMESPACES('http://example.com/myns' AS x, 'http://example.com/b' AS \"B\"), '/x:example/x:item' PASSING (SELECT data FROM xmldata) COLUMNS foo INT PATH '@foo', bar INT PATH '@B:bar')"
+    );
+}
+
 #[test]
 fn test_match_recognize() {
     use MatchRecognizePattern::*;