Support mssql json and xml extensions

fixes #1042

See the documentation for the FOR clause here: https://learn.microsoft.com/en-us/sql/t-sql/queries/select-for-clause-transact-sql?view=sql-server-ver16

Author: lovasoa

src/ast/mod.rs

@@ -37,12 +37,12 @@ pub use self::ddl::{
 };
 pub use self::operator::{BinaryOperator, UnaryOperator};
 pub use self::query::{
-    Cte, Distinct, ExceptSelectItem, ExcludeSelectItem, Fetch, GroupByExpr, IdentWithAlias, Join,
-    JoinConstraint, JoinOperator, LateralView, LockClause, LockType, NamedWindowDefinition,
-    NonBlock, Offset, OffsetRows, OrderByExpr, Query, RenameSelectItem, ReplaceSelectElement,
-    ReplaceSelectItem, Select, SelectInto, SelectItem, SetExpr, SetOperator, SetQuantifier, Table,
-    TableAlias, TableFactor, TableVersion, TableWithJoins, Top, Values, WildcardAdditionalOptions,
-    With,
+    Cte, Distinct, ExceptSelectItem, ExcludeSelectItem, Fetch, ForClause, ForJson, ForXml,
+    GroupByExpr, IdentWithAlias, Join, JoinConstraint, JoinOperator, LateralView, LockClause,
+    LockType, NamedWindowDefinition, NonBlock, Offset, OffsetRows, OrderByExpr, Query,
+    RenameSelectItem, ReplaceSelectElement, ReplaceSelectItem, Select, SelectInto, SelectItem,
+    SetExpr, SetOperator, SetQuantifier, Table, TableAlias, TableFactor, TableVersion,
+    TableWithJoins, Top, Values, WildcardAdditionalOptions, With,
 };
 pub use self::value::{
     escape_quoted_string, DateTimeField, DollarQuotedString, TrimWhereField, Value,

src/ast/query.rs

@@ -45,6 +45,10 @@ pub struct Query {
     pub fetch: Option<Fetch>,
     /// `FOR { UPDATE | SHARE } [ OF table_name ] [ SKIP LOCKED | NOWAIT ]`
     pub locks: Vec<LockClause>,
+    /// `FOR XML { RAW | AUTO | EXPLICIT | PATH } [ , ELEMENTS ]`
+    /// `FOR JSON { AUTO | PATH } [ , INCLUDE_NULL_VALUES ]`
+    /// (MSSQL-specific)
+    pub for_clause: Option<ForClause>,
 }
 
 impl fmt::Display for Query {
@@ -71,6 +75,9 @@ impl fmt::Display for Query {
         if !self.locks.is_empty() {
             write!(f, " {}", display_separated(&self.locks, " "))?;
         }
+        if let Some(ref for_clause) = self.for_clause {
+            write!(f, " {}", for_clause)?;
+        }
         Ok(())
     }
 }
@@ -1315,3 +1322,125 @@ impl fmt::Display for GroupByExpr {
         }
     }
 }
+
+/// FOR XML or FOR JSON clause, specific to MSSQL
+/// (formats the output of a query as XML or JSON)
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum ForClause {
+    Browse,
+    Json {
+        for_json: ForJson,
+        root: Option<String>,
+        include_null_values: bool,
+        without_array_wrapper: bool,
+    },
+    Xml {
+        for_xml: ForXml,
+        elements: bool,
+        binary_base64: bool,
+        root: Option<String>,
+        r#type: bool,
+    },
+}
+
+impl fmt::Display for ForClause {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            ForClause::Browse => write!(f, "FOR BROWSE"),
+            ForClause::Json {
+                for_json,
+                root,
+                include_null_values,
+                without_array_wrapper,
+            } => {
+                write!(f, "FOR JSON ")?;
+                write!(f, "{}", for_json)?;
+                if let Some(root) = root {
+                    write!(f, ", ROOT('{}')", root)?;
+                }
+                if *include_null_values {
+                    write!(f, ", INCLUDE_NULL_VALUES")?;
+                }
+                if *without_array_wrapper {
+                    write!(f, ", WITHOUT_ARRAY_WRAPPER")?;
+                }
+                Ok(())
+            }
+            ForClause::Xml {
+                for_xml,
+                elements,
+                binary_base64,
+                root,
+                r#type,
+            } => {
+                write!(f, "FOR XML ")?;
+                write!(f, "{}", for_xml)?;
+                if *binary_base64 {
+                    write!(f, ", BINARY BASE64")?;
+                }
+                if *r#type {
+                    write!(f, ", TYPE")?;
+                }
+                if let Some(root) = root {
+                    write!(f, ", ROOT('{}')", root)?;
+                }
+                if *elements {
+                    write!(f, ", ELEMENTS")?;
+                }
+                Ok(())
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum ForXml {
+    Raw(Option<String>),
+    Auto,
+    Explicit,
+    Path(Option<String>),
+}
+
+impl fmt::Display for ForXml {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            ForXml::Raw(root) => {
+                write!(f, "RAW")?;
+                if let Some(root) = root {
+                    write!(f, "('{}')", root)?;
+                }
+                Ok(())
+            }
+            ForXml::Auto => write!(f, "AUTO"),
+            ForXml::Explicit => write!(f, "EXPLICIT"),
+            ForXml::Path(root) => {
+                write!(f, "PATH")?;
+                if let Some(root) = root {
+                    write!(f, "('{}')", root)?;
+                }
+                Ok(())
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub enum ForJson {
+    Auto,
+    Path,
+}
+
+impl fmt::Display for ForJson {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            ForJson::Auto => write!(f, "AUTO"),
+            ForJson::Path => write!(f, "PATH"),
+        }
+    }
+}

src/keywords.rs

@@ -97,11 +97,13 @@ define_keywords!(
     ATOMIC,
     ATTACH,
     AUTHORIZATION,
+    AUTO,
     AUTOINCREMENT,
     AUTO_INCREMENT,
     AVG,
     AVRO,
     BACKWARD,
+    BASE64,
     BEGIN,
     BEGIN_FRAME,
     BEGIN_PARTITION,
@@ -116,6 +118,7 @@ define_keywords!(
     BOOL,
     BOOLEAN,
     BOTH,
+    BROWSE,
     BTREE,
     BY,
     BYPASSRLS,
@@ -232,6 +235,7 @@ define_keywords!(
     DYNAMIC,
     EACH,
     ELEMENT,
+    ELEMENTS,
     ELSE,
     ENCODING,
     ENCRYPTION,
@@ -256,6 +260,7 @@ define_keywords!(
     EXP,
     EXPANSION,
     EXPLAIN,
+    EXPLICIT,
     EXTENDED,
     EXTERNAL,
     EXTRACT,
@@ -319,6 +324,7 @@ define_keywords!(
     IMMUTABLE,
     IN,
     INCLUDE,
+    INCLUDE_NULL_VALUES,
     INCREMENT,
     INDEX,
     INDICATOR,
@@ -463,6 +469,7 @@ define_keywords!(
     PARTITIONED,
     PARTITIONS,
     PASSWORD,
+    PATH,
     PATTERN,
     PERCENT,
     PERCENTILE_CONT,
@@ -494,6 +501,7 @@ define_keywords!(
     QUOTE,
     RANGE,
     RANK,
+    RAW,
     RCFILE,
     READ,
     READS,
@@ -535,6 +543,7 @@ define_keywords!(
     ROLE,
     ROLLBACK,
     ROLLUP,
+    ROOT,
     ROW,
     ROWID,
     ROWS,
@@ -682,8 +691,10 @@ define_keywords!(
     WITH,
     WITHIN,
     WITHOUT,
+    WITHOUT_ARRAY_WRAPPER,
     WORK,
     WRITE,
+    XML,
     XOR,
     YEAR,
     ZONE,
@@ -732,6 +743,7 @@ pub const RESERVED_FOR_TABLE_ALIAS: &[Keyword] = &[
     Keyword::QUALIFY,
     Keyword::WINDOW,
     Keyword::END,
+    Keyword::FOR,
     // for MYSQL PARTITION SELECTION
     Keyword::PARTITION,
 ];