Add support for constraint characteristics clause (#1099)

src/ast/ddl.rs

@@ -385,6 +385,7 @@ pub enum TableConstraint {
         columns: Vec<Ident>,
         /// Whether this is a `PRIMARY KEY` or just a `UNIQUE` constraint
         is_primary: bool,
+        characteristics: Option<ConstraintCharacteristics>,
     },
     /// A referential integrity constraint (`[ CONSTRAINT <name> ] FOREIGN KEY (<columns>)
     /// REFERENCES <foreign_table> (<referred_columns>)
@@ -398,6 +399,7 @@ pub enum TableConstraint {
         referred_columns: Vec<Ident>,
         on_delete: Option<ReferentialAction>,
         on_update: Option<ReferentialAction>,
+        characteristics: Option<ConstraintCharacteristics>,
     },
     /// `[ CONSTRAINT <name> ] CHECK (<expr>)`
     Check {
@@ -454,13 +456,22 @@ impl fmt::Display for TableConstraint {
                 name,
                 columns,
                 is_primary,
-            } => write!(
-                f,
-                "{}{} ({})",
-                display_constraint_name(name),
-                if *is_primary { "PRIMARY KEY" } else { "UNIQUE" },
-                display_comma_separated(columns)
-            ),
+                characteristics,
+            } => {
+                write!(
+                    f,
+                    "{}{} ({})",
+                    display_constraint_name(name),
+                    if *is_primary { "PRIMARY KEY" } else { "UNIQUE" },
+                    display_comma_separated(columns)
+                )?;
+
+                if let Some(characteristics) = characteristics {
+                    write!(f, " {}", characteristics)?;
+                }
+
+                Ok(())
+            }
             TableConstraint::ForeignKey {
                 name,
                 columns,
@@ -468,6 +479,7 @@ impl fmt::Display for TableConstraint {
                 referred_columns,
                 on_delete,
                 on_update,
+                characteristics,
             } => {
                 write!(
                     f,
@@ -483,6 +495,9 @@ impl fmt::Display for TableConstraint {
                 if let Some(action) = on_update {
                     write!(f, " ON UPDATE {action}")?;
                 }
+                if let Some(characteristics) = characteristics {
+                    write!(f, " {}", characteristics)?;
+                }
                 Ok(())
             }
             TableConstraint::Check { name, expr } => {
@@ -713,20 +728,24 @@ pub enum ColumnOption {
     NotNull,
     /// `DEFAULT <restricted-expr>`
     Default(Expr),
-    /// `{ PRIMARY KEY | UNIQUE }`
+    /// `{ PRIMARY KEY | UNIQUE } [<constraint_characteristics>]`
     Unique {
         is_primary: bool,
+        characteristics: Option<ConstraintCharacteristics>,
     },
     /// A referential integrity constraint (`[FOREIGN KEY REFERENCES
     /// <foreign_table> (<referred_columns>)
     /// { [ON DELETE <referential_action>] [ON UPDATE <referential_action>] |
     ///   [ON UPDATE <referential_action>] [ON DELETE <referential_action>]
-    /// }`).
+    /// }
+    /// [<constraint_characteristics>]
+    /// `).
     ForeignKey {
         foreign_table: ObjectName,
         referred_columns: Vec<Ident>,
         on_delete: Option<ReferentialAction>,
         on_update: Option<ReferentialAction>,
+        characteristics: Option<ConstraintCharacteristics>,
     },
     /// `CHECK (<expr>)`
     Check(Expr),
@@ -764,14 +783,22 @@ impl fmt::Display for ColumnOption {
             Null => write!(f, "NULL"),
             NotNull => write!(f, "NOT NULL"),
             Default(expr) => write!(f, "DEFAULT {expr}"),
-            Unique { is_primary } => {
-                write!(f, "{}", if *is_primary { "PRIMARY KEY" } else { "UNIQUE" })
+            Unique {
+                is_primary,
+                characteristics,
+            } => {
+                write!(f, "{}", if *is_primary { "PRIMARY KEY" } else { "UNIQUE" })?;
+                if let Some(characteristics) = characteristics {
+                    write!(f, " {}", characteristics)?;
+                }
+                Ok(())
             }
             ForeignKey {
                 foreign_table,
                 referred_columns,
                 on_delete,
                 on_update,
+                characteristics,
             } => {
                 write!(f, "REFERENCES {foreign_table}")?;
                 if !referred_columns.is_empty() {
@@ -783,6 +810,9 @@ impl fmt::Display for ColumnOption {
                 if let Some(action) = on_update {
                     write!(f, " ON UPDATE {action}")?;
                 }
+                if let Some(characteristics) = characteristics {
+                    write!(f, " {}", characteristics)?;
+                }
                 Ok(())
             }
             Check(expr) => write!(f, "CHECK ({expr})"),
@@ -874,6 +904,84 @@ fn display_constraint_name(name: &'_ Option<Ident>) -> impl fmt::Display + '_ {
     ConstraintName(name)
 }
 
+/// `<constraint_characteristics> = [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ] [ ENFORCED | NOT ENFORCED ]`
+///
+/// Used in UNIQUE and foreign key constraints. The individual settings may occur in any order.
+#[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct ConstraintCharacteristics {
+    /// `[ DEFERRABLE | NOT DEFERRABLE ]`
+    pub deferrable: Option<bool>,
+    /// `[ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]`
+    pub initially: Option<DeferrableInitial>,
+    /// `[ ENFORCED | NOT ENFORCED ]`
+    pub enforced: Option<bool>,
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum DeferrableInitial {
+    /// `INITIALLY IMMEDIATE`
+    Immediate,
+    /// `INITIALLY DEFERRED`
+    Deferred,
+}
+
+impl ConstraintCharacteristics {
+    fn deferrable_text(&self) -> Option<&'static str> {
+        self.deferrable.map(|deferrable| {
+            if deferrable {
+                "DEFERRABLE"
+            } else {
+                "NOT DEFERRABLE"
+            }
+        })
+    }
+
+    fn initially_immediate_text(&self) -> Option<&'static str> {
+        self.initially
+            .map(|initially_immediate| match initially_immediate {
+                DeferrableInitial::Immediate => "INITIALLY IMMEDIATE",
+                DeferrableInitial::Deferred => "INITIALLY DEFERRED",
+            })
+    }
+
+    fn enforced_text(&self) -> Option<&'static str> {
+        self.enforced.map(
+            |enforced| {
+                if enforced {
+                    "ENFORCED"
+                } else {
+                    "NOT ENFORCED"
+                }
+            },
+        )
+    }
+}
+
+impl fmt::Display for ConstraintCharacteristics {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let deferrable = self.deferrable_text();
+        let initially_immediate = self.initially_immediate_text();
+        let enforced = self.enforced_text();
+
+        match (deferrable, initially_immediate, enforced) {
+            (None, None, None) => Ok(()),
+            (None, None, Some(enforced)) => write!(f, "{enforced}"),
+            (None, Some(initial), None) => write!(f, "{initial}"),
+            (None, Some(initial), Some(enforced)) => write!(f, "{initial} {enforced}"),
+            (Some(deferrable), None, None) => write!(f, "{deferrable}"),
+            (Some(deferrable), None, Some(enforced)) => write!(f, "{deferrable} {enforced}"),
+            (Some(deferrable), Some(initial), None) => write!(f, "{deferrable} {initial}"),
+            (Some(deferrable), Some(initial), Some(enforced)) => {
+                write!(f, "{deferrable} {initial} {enforced}")
+            }
+        }
+    }
+}
+
 /// `<referential_action> =
 /// { RESTRICT | CASCADE | SET NULL | NO ACTION | SET DEFAULT }`
 ///

src/ast/mod.rs

@@ -32,8 +32,9 @@ pub use self::data_type::{
 pub use self::dcl::{AlterRoleOperation, ResetConfig, RoleOption, SetConfigValue};
 pub use self::ddl::{
     AlterColumnOperation, AlterIndexOperation, AlterTableOperation, ColumnDef, ColumnOption,
-    ColumnOptionDef, GeneratedAs, GeneratedExpressionMode, IndexType, KeyOrIndexDisplay, Partition,
-    ProcedureParam, ReferentialAction, TableConstraint, UserDefinedTypeCompositeAttributeDef,
+    ColumnOptionDef, ConstraintCharacteristics, DeferrableInitial, GeneratedAs,
+    GeneratedExpressionMode, IndexType, KeyOrIndexDisplay, Partition, ProcedureParam,
+    ReferentialAction, TableConstraint, UserDefinedTypeCompositeAttributeDef,
     UserDefinedTypeRepresentation, ViewColumnDef,
 };
 pub use self::operator::{BinaryOperator, UnaryOperator};

src/keywords.rs

@@ -210,6 +210,7 @@ define_keywords!(
     DECIMAL,
     DECLARE,
     DEFAULT,
+    DEFERRABLE,
     DEFERRED,
     DELAYED,
     DELETE,
@@ -250,6 +251,7 @@ define_keywords!(
     ENDPOINT,
     END_FRAME,
     END_PARTITION,
+    ENFORCED,
     ENGINE,
     ENUM,
     EPOCH,
@@ -343,6 +345,7 @@ define_keywords!(
     INDEX,
     INDICATOR,
     INHERIT,
+    INITIALLY,
     INNER,
     INOUT,
     INPUTFORMAT,

src/parser/mod.rs

@@ -4478,9 +4478,17 @@ impl<'a> Parser<'a> {
         } else if self.parse_keyword(Keyword::DEFAULT) {
             Ok(Some(ColumnOption::Default(self.parse_expr()?)))
         } else if self.parse_keywords(&[Keyword::PRIMARY, Keyword::KEY]) {
-            Ok(Some(ColumnOption::Unique { is_primary: true }))
+            let characteristics = self.parse_constraint_characteristics()?;
+            Ok(Some(ColumnOption::Unique {
+                is_primary: true,
+                characteristics,
+            }))
         } else if self.parse_keyword(Keyword::UNIQUE) {
-            Ok(Some(ColumnOption::Unique { is_primary: false }))
+            let characteristics = self.parse_constraint_characteristics()?;
+            Ok(Some(ColumnOption::Unique {
+                is_primary: false,
+                characteristics,
+            }))
         } else if self.parse_keyword(Keyword::REFERENCES) {
             let foreign_table = self.parse_object_name(false)?;
             // PostgreSQL allows omitting the column list and
@@ -4499,11 +4507,14 @@ impl<'a> Parser<'a> {
                     break;
                 }
             }
+            let characteristics = self.parse_constraint_characteristics()?;
+
             Ok(Some(ColumnOption::ForeignKey {
                 foreign_table,
                 referred_columns,
                 on_delete,
                 on_update,
+                characteristics,
             }))
         } else if self.parse_keyword(Keyword::CHECK) {
             self.expect_token(&Token::LParen)?;
@@ -4658,6 +4669,47 @@ impl<'a> Parser<'a> {
         }
     }
 
+    pub fn parse_constraint_characteristics(
+        &mut self,
+    ) -> Result<Option<ConstraintCharacteristics>, ParserError> {
+        let mut cc = ConstraintCharacteristics {
+            deferrable: None,
+            initially: None,
+            enforced: None,
+        };
+
+        loop {
+            if cc.deferrable.is_none() && self.parse_keywords(&[Keyword::NOT, Keyword::DEFERRABLE])
+            {
+                cc.deferrable = Some(false);
+            } else if cc.deferrable.is_none() && self.parse_keyword(Keyword::DEFERRABLE) {
+                cc.deferrable = Some(true);
+            } else if cc.initially.is_none() && self.parse_keyword(Keyword::INITIALLY) {
+                if self.parse_keyword(Keyword::DEFERRED) {
+                    cc.initially = Some(DeferrableInitial::Deferred);
+                } else if self.parse_keyword(Keyword::IMMEDIATE) {
+                    cc.initially = Some(DeferrableInitial::Immediate);
+                } else {
+                    self.expected("one of DEFERRED or IMMEDIATE", self.peek_token())?;
+                }
+            } else if cc.enforced.is_none() && self.parse_keyword(Keyword::ENFORCED) {
+                cc.enforced = Some(true);
+            } else if cc.enforced.is_none()
+                && self.parse_keywords(&[Keyword::NOT, Keyword::ENFORCED])
+            {
+                cc.enforced = Some(false);
+            } else {
+                break;
+            }
+        }
+
+        if cc.deferrable.is_some() || cc.initially.is_some() || cc.enforced.is_some() {
+            Ok(Some(cc))
+        } else {
+            Ok(None)
+        }
+    }
+
     pub fn parse_optional_table_constraint(
         &mut self,
     ) -> Result<Option<TableConstraint>, ParserError> {
@@ -4681,10 +4733,12 @@ impl<'a> Parser<'a> {
                     .or(name);
 
                 let columns = self.parse_parenthesized_column_list(Mandatory, false)?;
+                let characteristics = self.parse_constraint_characteristics()?;
                 Ok(Some(TableConstraint::Unique {
                     name,
                     columns,
                     is_primary,
+                    characteristics,
                 }))
             }
             Token::Word(w) if w.keyword == Keyword::FOREIGN => {
@@ -4706,6 +4760,9 @@ impl<'a> Parser<'a> {
                         break;
                     }
                 }
+
+                let characteristics = self.parse_constraint_characteristics()?;
+
                 Ok(Some(TableConstraint::ForeignKey {
                     name,
                     columns,
@@ -4713,6 +4770,7 @@ impl<'a> Parser<'a> {
                     referred_columns,
                     on_delete,
                     on_update,
+                    characteristics,
                 }))
             }
             Token::Word(w) if w.keyword == Keyword::CHECK => {