draft triggers create and drop

src/backend/mod.rs

@@ -24,16 +24,20 @@ mod index_builder;
 mod query_builder;
 mod table_builder;
 mod table_ref_builder;
+mod trigger_builder;
+// mod trigger_ref_builder;
 
 pub use self::foreign_key_builder::*;
 pub use self::index_builder::*;
 pub use self::query_builder::*;
 pub use self::table_builder::*;
 pub use self::table_ref_builder::*;
+pub use self::trigger_builder::*;
+// pub use self::trigger_ref_builder::*;
 
 pub trait GenericBuilder: QueryBuilder + SchemaBuilder {}
 
-pub trait SchemaBuilder: TableBuilder + IndexBuilder + ForeignKeyBuilder {}
+pub trait SchemaBuilder: TableBuilder + IndexBuilder + ForeignKeyBuilder + TriggerBuilder {}
 
 pub trait QuotedBuilder {
     /// The type of quote the builder uses.

src/backend/mysql/mod.rs

@@ -2,6 +2,7 @@ pub(crate) mod foreign_key;
 pub(crate) mod index;
 pub(crate) mod query;
 pub(crate) mod table;
+pub(crate) mod trigger;
 
 use super::*;
 

src/backend/mysql/trigger.rs

@@ -0,0 +1,3 @@
+use super::*;
+
+impl TriggerBuilder for MysqlQueryBuilder {}

src/backend/postgres/mod.rs

@@ -3,6 +3,7 @@ pub(crate) mod foreign_key;
 pub(crate) mod index;
 pub(crate) mod query;
 pub(crate) mod table;
+pub(crate) mod trigger;
 pub(crate) mod types;
 
 use super::*;

src/backend/postgres/trigger.rs

@@ -0,0 +1,3 @@
+use super::*;
+
+impl TriggerBuilder for PostgresQueryBuilder {}

src/backend/sqlite/mod.rs

@@ -2,6 +2,7 @@ pub(crate) mod foreign_key;
 pub(crate) mod index;
 pub(crate) mod query;
 pub(crate) mod table;
+pub(crate) mod trigger;
 
 use super::*;
 

src/backend/sqlite/trigger.rs

@@ -0,0 +1,3 @@
+use super::*;
+
+impl TriggerBuilder for SqliteQueryBuilder {}

src/backend/trigger_builder.rs

@@ -0,0 +1,48 @@
+use crate::*;
+
+pub trait TriggerBuilder: TableRefBuilder {
+    /// Translate [`TriggerCreateStatement`] into SQL statement.
+    fn prepare_trigger_create_statement(
+        &self,
+        create: &TriggerCreateStatement,
+        sql: &mut dyn SqlWriter,
+    ) {
+        write!(sql, "CREATE TRIGGER ").unwrap();
+        self.prepare_create_trigger_if_not_exists(create, sql);
+
+        let trigger_ref = match &create.trigger.name {
+            Some(value) => value,
+            // auto-generate trigger name
+            _ => &create.trigger.trigger_ref(),
+        };
+        let trigger_ref: TableRef = trigger_ref.into();
+        self.prepare_table_ref_iden(&trigger_ref, sql);
+        write!(sql, " {} {} ON ", create.trigger.time, create.trigger.event).unwrap();
+        self.prepare_table_ref_iden(&create.trigger.table, sql);
+        write!(sql, " FOR EACH ROW\nBEGIN\n").unwrap();
+
+        write!(sql, "\nEND").unwrap();
+    }
+
+    /// Translate IF NOT EXISTS expression in [`TriggerCreateStatement`].
+    fn prepare_create_trigger_if_not_exists(
+        &self,
+        create: &TriggerCreateStatement,
+        sql: &mut dyn SqlWriter,
+    ) {
+        if create.if_not_exists {
+            write!(sql, "IF NOT EXISTS ").unwrap();
+        }
+    }
+
+    // /// Translate [`TriggerRef`] into SQL statement.
+    // fn prepare_table_ref(&self, trigger_ref: &TableRef, sql: &mut dyn SqlWriter) {
+    //     self.prepare_table_ref_iden(trigger_ref, sql)
+    // }
+
+    /// Translate [`TriggerDropStatement`] into SQL statement.
+    fn prepare_trigger_drop_statement(&self, drop: &TriggerDropStatement, sql: &mut dyn SqlWriter) {
+        write!(sql, "DROP TRIGGER ").unwrap();
+        self.prepare_table_ref_iden(&drop.name.clone().into(), sql);
+    }
+}

src/backend/trigger_ref_builder.rs

@@ -0,0 +1,12 @@
+use crate::*;
+
+pub trait TriggerRefBuilder: QuotedBuilder {
+    /// Translate [`TriggerRef`] that without values into SQL statement.
+    fn prepare_trigger_ref_iden(&self, table_ref: &TriggerRef, sql: &mut dyn SqlWriter) {
+        match table_ref {
+            TriggerRef::Trigger(iden) => {
+                iden.prepare(sql.as_writer(), self.quote());
+            }
+        }
+    }
+}

src/lib.rs

@@ -824,6 +824,7 @@ pub mod query;
 pub mod schema;
 pub mod table;
 pub mod token;
+pub mod trigger;
 pub mod types;
 pub mod value;
 
@@ -841,6 +842,7 @@ pub use query::*;
 pub use schema::*;
 pub use table::*;
 pub use token::*;
+pub use trigger::*;
 pub use types::*;
 pub use value::*;
 

src/trigger/create.rs

@@ -0,0 +1,40 @@
+use super::DefinedTrigger;
+use crate::{backend::SchemaBuilder, SchemaStatementBuilder};
+use inherent::inherent;
+
+#[derive(Debug, Clone)]
+pub struct TriggerCreateStatement {
+    pub(crate) trigger: DefinedTrigger,
+    pub(crate) if_not_exists: bool,
+}
+
+impl TriggerCreateStatement {
+    pub fn new(trigger: DefinedTrigger) -> Self {
+        TriggerCreateStatement {
+            trigger,
+            if_not_exists: false,
+        }
+    }
+
+    pub fn if_not_exists(&mut self) -> &mut Self {
+        self.if_not_exists = true;
+        self
+    }
+}
+
+#[inherent]
+impl SchemaStatementBuilder for TriggerCreateStatement {
+    pub fn build<T: SchemaBuilder>(&self, schema_builder: T) -> String {
+        let mut sql = String::with_capacity(256);
+        schema_builder.prepare_trigger_create_statement(self, &mut sql);
+        sql
+    }
+
+    pub fn build_any(&self, schema_builder: &dyn SchemaBuilder) -> String {
+        let mut sql = String::with_capacity(256);
+        schema_builder.prepare_trigger_create_statement(self, &mut sql);
+        sql
+    }
+
+    pub fn to_string<T: SchemaBuilder>(&self, schema_builder: T) -> String;
+}

src/trigger/drop.rs

@@ -0,0 +1,99 @@
+use super::TriggerRef;
+use crate::{backend::SchemaBuilder, SchemaStatementBuilder};
+use inherent::inherent;
+
+/// Drop a trigger
+///
+/// # Examples
+///
+/// ```
+/// use sea_query::{tests_cfg::*, *};
+///
+/// let trigger = NamedTrigger::new("my_trigger")
+///     .to_owned();
+///
+/// let drop_stmt = trigger.drop();
+///
+/// assert_eq!(
+///     drop_stmt.to_string(MysqlQueryBuilder),
+///     r#"DROP TRIGGER `my_trigger`"#
+/// );
+/// assert_eq!(
+///     drop_stmt.to_string(PostgresQueryBuilder),
+///     r#"DROP TRIGGER "my_trigger""#
+/// );
+/// assert_eq!(
+///     drop_stmt.to_string(SqliteQueryBuilder),
+///     r#"DROP TRIGGER "my_trigger""#
+/// );
+/// ```
+///
+/// # Trigger names can be derived from table name, action and action time
+///
+/// ```
+/// use sea_query::{tests_cfg::*, *};
+///
+/// let trigger = UnnamedTrigger::new()
+///     .before_insert(Glyph::Table);
+///
+/// let drop_stmt = trigger.drop();
+///
+/// assert_eq!(
+///     drop_stmt.to_string(MysqlQueryBuilder),
+///     r#"DROP TRIGGER `t_glyph_before_insert`"#
+/// );
+/// assert_eq!(
+///     drop_stmt.to_string(PostgresQueryBuilder),
+///     r#"DROP TRIGGER "t_glyph_before_insert""#
+/// );
+/// assert_eq!(
+///     drop_stmt.to_string(SqliteQueryBuilder),
+///     r#"DROP TRIGGER "t_glyph_before_insert""#
+/// );
+///
+/// ```
+#[derive(Debug, Clone)]
+pub struct TriggerDropStatement {
+    pub(crate) name: TriggerRef,
+    pub(crate) if_exists: bool,
+}
+
+impl TriggerDropStatement {
+    /// Construct drop table statement
+    pub fn new(name: TriggerRef) -> Self {
+        Self {
+            name: name,
+            if_exists: false,
+        }
+    }
+
+    /// Drop table if exists
+    pub fn if_exists(&mut self) -> &mut Self {
+        self.if_exists = true;
+        self
+    }
+
+    pub fn take(&mut self) -> Self {
+        Self {
+            name: std::mem::take(&mut self.name),
+            if_exists: self.if_exists,
+        }
+    }
+}
+
+#[inherent]
+impl SchemaStatementBuilder for TriggerDropStatement {
+    pub fn build<T: SchemaBuilder>(&self, schema_builder: T) -> String {
+        let mut sql = String::with_capacity(256);
+        schema_builder.prepare_trigger_drop_statement(self, &mut sql);
+        sql
+    }
+
+    pub fn build_any(&self, schema_builder: &dyn SchemaBuilder) -> String {
+        let mut sql = String::with_capacity(256);
+        schema_builder.prepare_trigger_drop_statement(self, &mut sql);
+        sql
+    }
+
+    pub fn to_string<T: SchemaBuilder>(&self, schema_builder: T) -> String;
+}