Added support for SQLite triggers (#2037)

Co-authored-by: Ifeanyi Ubah <ify1992@yahoo.com>

Author: LucaCappelletti94

src/ast/ddl.rs

@@ -2922,6 +2922,26 @@ impl Spanned for RenameTableNameKind {
     }
 }
 
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+/// Whether the syntax used for the trigger object (ROW or STATEMENT) is `FOR` or `FOR EACH`.
+pub enum TriggerObjectKind {
+    /// The `FOR` syntax is used.
+    For(TriggerObject),
+    /// The `FOR EACH` syntax is used.
+    ForEach(TriggerObject),
+}
+
+impl Display for TriggerObjectKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            TriggerObjectKind::For(obj) => write!(f, "FOR {obj}"),
+            TriggerObjectKind::ForEach(obj) => write!(f, "FOR EACH {obj}"),
+        }
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
@@ -2943,6 +2963,23 @@ pub struct CreateTrigger {
     ///
     /// [MsSql](https://learn.microsoft.com/en-us/sql/t-sql/statements/create-trigger-transact-sql?view=sql-server-ver16#arguments)
     pub or_alter: bool,
+    /// True if this is a temporary trigger.
+    ///
+    /// Examples:
+    ///
+    /// ```sql
+    /// CREATE TEMP TRIGGER trigger_name
+    /// ```
+    ///
+    /// or
+    ///
+    /// ```sql
+    /// CREATE TEMPORARY TRIGGER trigger_name;
+    /// CREATE TEMP TRIGGER trigger_name;
+    /// ```
+    ///
+    /// [SQLite](https://sqlite.org/lang_createtrigger.html#temp_triggers_on_non_temp_tables)
+    pub temporary: bool,
     /// The `OR REPLACE` clause is used to re-create the trigger if it already exists.
     ///
     /// Example:
@@ -2987,6 +3024,8 @@ pub struct CreateTrigger {
     /// ```
     pub period: TriggerPeriod,
     /// Whether the trigger period was specified before the target table name.
+    /// This does not refer to whether the period is BEFORE, AFTER, or INSTEAD OF,
+    /// but rather the position of the period clause in relation to the table name.
     ///
     /// ```sql
     /// -- period_before_table == true: Postgres, MySQL, and standard SQL
@@ -3006,9 +3045,9 @@ pub struct CreateTrigger {
     pub referencing: Vec<TriggerReferencing>,
     /// This specifies whether the trigger function should be fired once for
     /// every row affected by the trigger event, or just once per SQL statement.
-    pub trigger_object: TriggerObject,
-    /// Whether to include the `EACH` term of the `FOR EACH`, as it is optional syntax.
-    pub include_each: bool,
+    /// This is optional in some SQL dialects, such as SQLite, and if not specified, in
+    /// those cases, the implied default is `FOR EACH ROW`.
+    pub trigger_object: Option<TriggerObjectKind>,
     ///  Triggering conditions
     pub condition: Option<Expr>,
     /// Execute logic block
@@ -3025,6 +3064,7 @@ impl Display for CreateTrigger {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let CreateTrigger {
             or_alter,
+            temporary,
             or_replace,
             is_constraint,
             name,
@@ -3036,15 +3076,15 @@ impl Display for CreateTrigger {
             referencing,
             trigger_object,
             condition,
-            include_each,
             exec_body,
             statements_as,
             statements,
             characteristics,
         } = self;
         write!(
             f,
-            "CREATE {or_alter}{or_replace}{is_constraint}TRIGGER {name} ",
+            "CREATE {temporary}{or_alter}{or_replace}{is_constraint}TRIGGER {name} ",
+            temporary = if *temporary { "TEMPORARY " } else { "" },
             or_alter = if *or_alter { "OR ALTER " } else { "" },
             or_replace = if *or_replace { "OR REPLACE " } else { "" },
             is_constraint = if *is_constraint { "CONSTRAINT " } else { "" },
@@ -3076,10 +3116,8 @@ impl Display for CreateTrigger {
             write!(f, " REFERENCING {}", display_separated(referencing, " "))?;
         }
 
-        if *include_each {
-            write!(f, " FOR EACH {trigger_object}")?;
-        } else if exec_body.is_some() {
-            write!(f, " FOR {trigger_object}")?;
+        if let Some(trigger_object) = trigger_object {
+            write!(f, " {trigger_object}")?;
         }
         if let Some(condition) = condition {
             write!(f, " WHEN {condition}")?;

src/ast/mod.rs

@@ -70,8 +70,8 @@ pub use self::ddl::{
     IdentityParameters, IdentityProperty, IdentityPropertyFormatKind, IdentityPropertyKind,
     IdentityPropertyOrder, IndexColumn, IndexOption, IndexType, KeyOrIndexDisplay, Msck,
     NullsDistinctOption, Owner, Partition, ProcedureParam, ReferentialAction, RenameTableNameKind,
-    ReplicaIdentity, TagsColumnOption, Truncate, UserDefinedTypeCompositeAttributeDef,
-    UserDefinedTypeRepresentation, ViewColumnDef,
+    ReplicaIdentity, TagsColumnOption, TriggerObjectKind, Truncate,
+    UserDefinedTypeCompositeAttributeDef, UserDefinedTypeRepresentation, ViewColumnDef,
 };
 pub use self::dml::{Delete, Insert, Update};
 pub use self::operator::{BinaryOperator, UnaryOperator};

src/dialect/mssql.rs

@@ -18,7 +18,7 @@
 use crate::ast::helpers::attached_token::AttachedToken;
 use crate::ast::{
     BeginEndStatements, ConditionalStatementBlock, ConditionalStatements, CreateTrigger,
-    GranteesType, IfStatement, Statement, TriggerObject,
+    GranteesType, IfStatement, Statement,
 };
 use crate::dialect::Dialect;
 use crate::keywords::{self, Keyword};
@@ -254,6 +254,7 @@ impl MsSqlDialect {
 
         Ok(CreateTrigger {
             or_alter,
+            temporary: false,
             or_replace: false,
             is_constraint: false,
             name,
@@ -263,8 +264,7 @@ impl MsSqlDialect {
             table_name,
             referenced_table_name: None,
             referencing: Vec::new(),
-            trigger_object: TriggerObject::Statement,
-            include_each: false,
+            trigger_object: None,
             condition: None,
             exec_body: None,
             statements_as: true,

src/parser/mod.rs

@@ -4753,9 +4753,9 @@ impl<'a> Parser<'a> {
         } else if self.parse_keyword(Keyword::DOMAIN) {
             self.parse_create_domain()
         } else if self.parse_keyword(Keyword::TRIGGER) {
-            self.parse_create_trigger(or_alter, or_replace, false)
+            self.parse_create_trigger(temporary, or_alter, or_replace, false)
         } else if self.parse_keywords(&[Keyword::CONSTRAINT, Keyword::TRIGGER]) {
-            self.parse_create_trigger(or_alter, or_replace, true)
+            self.parse_create_trigger(temporary, or_alter, or_replace, true)
         } else if self.parse_keyword(Keyword::MACRO) {
             self.parse_create_macro(or_replace, temporary)
         } else if self.parse_keyword(Keyword::SECRET) {
@@ -5551,7 +5551,8 @@ impl<'a> Parser<'a> {
     /// DROP TRIGGER [ IF EXISTS ] name ON table_name [ CASCADE | RESTRICT ]
     /// ```
     pub fn parse_drop_trigger(&mut self) -> Result<Statement, ParserError> {
-        if !dialect_of!(self is PostgreSqlDialect | GenericDialect | MySqlDialect | MsSqlDialect) {
+        if !dialect_of!(self is PostgreSqlDialect | SQLiteDialect | GenericDialect | MySqlDialect | MsSqlDialect)
+        {
             self.prev_token();
             return self.expected("an object type after DROP", self.peek_token());
         }
@@ -5579,11 +5580,13 @@ impl<'a> Parser<'a> {
 
     pub fn parse_create_trigger(
         &mut self,
+        temporary: bool,
         or_alter: bool,
         or_replace: bool,
         is_constraint: bool,
     ) -> Result<Statement, ParserError> {
-        if !dialect_of!(self is PostgreSqlDialect | GenericDialect | MySqlDialect | MsSqlDialect) {
+        if !dialect_of!(self is PostgreSqlDialect | SQLiteDialect | GenericDialect | MySqlDialect | MsSqlDialect)
+        {
             self.prev_token();
             return self.expected("an object type after CREATE", self.peek_token());
         }
@@ -5610,14 +5613,25 @@ impl<'a> Parser<'a> {
             }
         }
 
-        self.expect_keyword_is(Keyword::FOR)?;
-        let include_each = self.parse_keyword(Keyword::EACH);
-        let trigger_object =
-            match self.expect_one_of_keywords(&[Keyword::ROW, Keyword::STATEMENT])? {
-                Keyword::ROW => TriggerObject::Row,
-                Keyword::STATEMENT => TriggerObject::Statement,
-                _ => unreachable!(),
-            };
+        let trigger_object = if self.parse_keyword(Keyword::FOR) {
+            let include_each = self.parse_keyword(Keyword::EACH);
+            let trigger_object =
+                match self.expect_one_of_keywords(&[Keyword::ROW, Keyword::STATEMENT])? {
+                    Keyword::ROW => TriggerObject::Row,
+                    Keyword::STATEMENT => TriggerObject::Statement,
+                    _ => unreachable!(),
+                };
+
+            Some(if include_each {
+                TriggerObjectKind::ForEach(trigger_object)
+            } else {
+                TriggerObjectKind::For(trigger_object)
+            })
+        } else {
+            let _ = self.parse_keyword(Keyword::FOR);
+
+            None
+        };
 
         let condition = self
             .parse_keyword(Keyword::WHEN)
@@ -5632,8 +5646,9 @@ impl<'a> Parser<'a> {
             statements = Some(self.parse_conditional_statements(&[Keyword::END])?);
         }
 
-        Ok(Statement::CreateTrigger(CreateTrigger {
+        Ok(CreateTrigger {
             or_alter,
+            temporary,
             or_replace,
             is_constraint,
             name,
@@ -5644,13 +5659,13 @@ impl<'a> Parser<'a> {
             referenced_table_name,
             referencing,
             trigger_object,
-            include_each,
             condition,
             exec_body,
             statements_as: false,
             statements,
             characteristics,
-        }))
+        }
+        .into())
     }
 
     pub fn parse_trigger_period(&mut self) -> Result<TriggerPeriod, ParserError> {

tests/sqlparser_mssql.rs

@@ -2388,6 +2388,7 @@ fn parse_create_trigger() {
         create_stmt,
         Statement::CreateTrigger(CreateTrigger {
             or_alter: true,
+            temporary: false,
             or_replace: false,
             is_constraint: false,
             name: ObjectName::from(vec![Ident::new("reminder1")]),
@@ -2397,8 +2398,7 @@ fn parse_create_trigger() {
             table_name: ObjectName::from(vec![Ident::new("Sales"), Ident::new("Customer")]),
             referenced_table_name: None,
             referencing: vec![],
-            trigger_object: TriggerObject::Statement,
-            include_each: false,
+            trigger_object: None,
             condition: None,
             exec_body: None,
             statements_as: true,

tests/sqlparser_mysql.rs

@@ -4018,6 +4018,7 @@ fn parse_create_trigger() {
         create_stmt,
         Statement::CreateTrigger(CreateTrigger {
             or_alter: false,
+            temporary: false,
             or_replace: false,
             is_constraint: false,
             name: ObjectName::from(vec![Ident::new("emp_stamp")]),
@@ -4027,8 +4028,7 @@ fn parse_create_trigger() {
             table_name: ObjectName::from(vec![Ident::new("emp")]),
             referenced_table_name: None,
             referencing: vec![],
-            trigger_object: TriggerObject::Row,
-            include_each: true,
+            trigger_object: Some(TriggerObjectKind::ForEach(TriggerObject::Row)),
             condition: None,
             exec_body: Some(TriggerExecBody {
                 exec_type: TriggerExecBodyType::Function,