sea-orm/src/query/helper.rs
2021-10-29 10:38:30 +03:00

441 lines
14 KiB
Rust

use crate::{
ColumnTrait, EntityTrait, Identity, IntoIdentity, IntoSimpleExpr, Iterable, ModelTrait,
PrimaryKeyToColumn, RelationDef,
};
use sea_query::{
Alias, Expr, Iden, IntoCondition, LockType, SeaRc, SelectExpr, SelectStatement, SimpleExpr,
TableRef,
};
pub use sea_query::{Condition, ConditionalStatement, DynIden, JoinType, Order, OrderedStatement};
// LINT: when the column does not appear in tables selected from
// LINT: when there is a group by clause, but some columns don't have aggregate functions
// LINT: when the join table or column does not exists
/// Constraints for any type that needs to perform select statements on a Model
pub trait QuerySelect: Sized {
#[allow(missing_docs)]
type QueryStatement;
/// Add the select SQL statement
fn query(&mut self) -> &mut SelectStatement;
/// Clear the selection list
fn select_only(mut self) -> Self {
self.query().clear_selects();
self
}
/// Add a select column
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
///
/// assert_eq!(
/// cake::Entity::find()
/// .select_only()
/// .column(cake::Column::Name)
/// .build(DbBackend::Postgres)
/// .to_string(),
/// r#"SELECT "cake"."name" FROM "cake""#
/// );
/// ```
fn column<C>(mut self, col: C) -> Self
where
C: ColumnTrait,
{
self.query().expr(col.into_simple_expr());
self
}
/// Add a select column with alias
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
///
/// assert_eq!(
/// cake::Entity::find()
/// .select_only()
/// .column_as(cake::Column::Id.count(), "count")
/// .build(DbBackend::Postgres)
/// .to_string(),
/// r#"SELECT COUNT("cake"."id") AS "count" FROM "cake""#
/// );
/// ```
fn column_as<C, I>(mut self, col: C, alias: I) -> Self
where
C: IntoSimpleExpr,
I: IntoIdentity,
{
self.query().expr(SelectExpr {
expr: col.into_simple_expr(),
alias: Some(SeaRc::new(alias.into_identity())),
});
self
}
/// Add a group by column
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
///
/// assert_eq!(
/// cake::Entity::find()
/// .select_only()
/// .column(cake::Column::Name)
/// .group_by(cake::Column::Name)
/// .build(DbBackend::Postgres)
/// .to_string(),
/// r#"SELECT "cake"."name" FROM "cake" GROUP BY "cake"."name""#
/// );
/// ```
fn group_by<C>(mut self, col: C) -> Self
where
C: IntoSimpleExpr,
{
self.query().add_group_by(vec![col.into_simple_expr()]);
self
}
/// Add an AND HAVING expression
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
///
/// assert_eq!(
/// cake::Entity::find()
/// .having(cake::Column::Id.eq(4))
/// .having(cake::Column::Id.eq(5))
/// .build(DbBackend::MySql)
/// .to_string(),
/// "SELECT `cake`.`id`, `cake`.`name` FROM `cake` HAVING `cake`.`id` = 4 AND `cake`.`id` = 5"
/// );
/// ```
fn having<F>(mut self, filter: F) -> Self
where
F: IntoCondition,
{
self.query().cond_having(filter.into_condition());
self
}
#[doc(hidden)]
fn join_join(mut self, join: JoinType, rel: RelationDef, via: Option<RelationDef>) -> Self {
if let Some(via) = via {
self = self.join(join, via)
}
self.join(join, rel)
}
#[doc(hidden)]
fn join_join_rev(mut self, join: JoinType, rel: RelationDef, via: Option<RelationDef>) -> Self {
self = self.join_rev(join, rel);
if let Some(via) = via {
self = self.join_rev(join, via)
}
self
}
/// Join via [`RelationDef`].
fn join(mut self, join: JoinType, rel: RelationDef) -> Self {
self.query()
.join(join, rel.to_tbl.clone(), join_condition(rel));
self
}
/// Join via [`RelationDef`] but in reverse direction.
/// Assume when there exist a relation A to B.
/// You can reverse join B from A.
fn join_rev(mut self, join: JoinType, rel: RelationDef) -> Self {
self.query()
.join(join, rel.from_tbl.clone(), join_condition(rel));
self
}
/// Select lock
fn lock(mut self, lock_type: LockType) -> Self {
self.query().lock(lock_type);
self
}
/// Select lock shared
fn lock_shared(mut self) -> Self {
self.query().lock_shared();
self
}
/// Select lock exclusive
fn lock_exclusive(mut self) -> Self {
self.query().lock_exclusive();
self
}
}
// LINT: when the column does not appear in tables selected from
/// Performs ORDER BY operations
pub trait QueryOrder: Sized {
#[allow(missing_docs)]
type QueryStatement: OrderedStatement;
/// Add the query to perform an ORDER BY operation
fn query(&mut self) -> &mut SelectStatement;
/// Add an order_by expression
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
///
/// assert_eq!(
/// cake::Entity::find()
/// .order_by(cake::Column::Id, Order::Asc)
/// .order_by(cake::Column::Name, Order::Desc)
/// .build(DbBackend::MySql)
/// .to_string(),
/// "SELECT `cake`.`id`, `cake`.`name` FROM `cake` ORDER BY `cake`.`id` ASC, `cake`.`name` DESC"
/// );
/// ```
fn order_by<C>(mut self, col: C, ord: Order) -> Self
where
C: IntoSimpleExpr,
{
self.query().order_by_expr(col.into_simple_expr(), ord);
self
}
/// Add an order_by expression (ascending)
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
///
/// assert_eq!(
/// cake::Entity::find()
/// .order_by_asc(cake::Column::Id)
/// .build(DbBackend::MySql)
/// .to_string(),
/// "SELECT `cake`.`id`, `cake`.`name` FROM `cake` ORDER BY `cake`.`id` ASC"
/// );
/// ```
fn order_by_asc<C>(mut self, col: C) -> Self
where
C: IntoSimpleExpr,
{
self.query()
.order_by_expr(col.into_simple_expr(), Order::Asc);
self
}
/// Add an order_by expression (descending)
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
///
/// assert_eq!(
/// cake::Entity::find()
/// .order_by_desc(cake::Column::Id)
/// .build(DbBackend::MySql)
/// .to_string(),
/// "SELECT `cake`.`id`, `cake`.`name` FROM `cake` ORDER BY `cake`.`id` DESC"
/// );
/// ```
fn order_by_desc<C>(mut self, col: C) -> Self
where
C: IntoSimpleExpr,
{
self.query()
.order_by_expr(col.into_simple_expr(), Order::Desc);
self
}
}
// LINT: when the column does not appear in tables selected from
/// Perform a FILTER opertation on a statement
pub trait QueryFilter: Sized {
#[allow(missing_docs)]
type QueryStatement: ConditionalStatement;
/// Add the query to perform a FILTER on
fn query(&mut self) -> &mut Self::QueryStatement;
/// Add an AND WHERE expression
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
///
/// assert_eq!(
/// cake::Entity::find()
/// .filter(cake::Column::Id.eq(4))
/// .filter(cake::Column::Id.eq(5))
/// .build(DbBackend::MySql)
/// .to_string(),
/// "SELECT `cake`.`id`, `cake`.`name` FROM `cake` WHERE `cake`.`id` = 4 AND `cake`.`id` = 5"
/// );
/// ```
///
/// Add a condition tree.
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
///
/// assert_eq!(
/// cake::Entity::find()
/// .filter(
/// Condition::any()
/// .add(cake::Column::Id.eq(4))
/// .add(cake::Column::Id.eq(5))
/// )
/// .build(DbBackend::MySql)
/// .to_string(),
/// "SELECT `cake`.`id`, `cake`.`name` FROM `cake` WHERE `cake`.`id` = 4 OR `cake`.`id` = 5"
/// );
/// ```
///
/// Add a runtime-built condition tree.
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
/// struct Input {
/// name: Option<String>,
/// }
/// let input = Input {
/// name: Some("cheese".to_owned()),
/// };
///
/// let mut conditions = Condition::all();
/// if let Some(name) = input.name {
/// conditions = conditions.add(cake::Column::Name.contains(&name));
/// }
///
/// assert_eq!(
/// cake::Entity::find()
/// .filter(conditions)
/// .build(DbBackend::MySql)
/// .to_string(),
/// "SELECT `cake`.`id`, `cake`.`name` FROM `cake` WHERE `cake`.`name` LIKE '%cheese%'"
/// );
/// ```
///
/// Add a runtime-built condition tree, functional-way.
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
/// struct Input {
/// name: Option<String>,
/// }
/// let input = Input {
/// name: Some("cheese".to_owned()),
/// };
///
/// assert_eq!(
/// cake::Entity::find()
/// .filter(
/// Condition::all().add_option(input.name.map(|n| cake::Column::Name.contains(&n)))
/// )
/// .build(DbBackend::MySql)
/// .to_string(),
/// "SELECT `cake`.`id`, `cake`.`name` FROM `cake` WHERE `cake`.`name` LIKE '%cheese%'"
/// );
/// ```
///
/// A slightly more complex example.
/// ```
/// use sea_orm::{entity::*, query::*, tests_cfg::cake, sea_query::Expr, DbBackend};
///
/// assert_eq!(
/// cake::Entity::find()
/// .filter(
/// Condition::all()
/// .add(
/// Condition::all()
/// .not()
/// .add(Expr::val(1).eq(1))
/// .add(Expr::val(2).eq(2))
/// )
/// .add(
/// Condition::any()
/// .add(Expr::val(3).eq(3))
/// .add(Expr::val(4).eq(4))
/// )
/// )
/// .build(DbBackend::Postgres)
/// .to_string(),
/// r#"SELECT "cake"."id", "cake"."name" FROM "cake" WHERE (NOT (1 = 1 AND 2 = 2)) AND (3 = 3 OR 4 = 4)"#
/// );
/// ```
/// Use a sea_query expression
/// ```
/// use sea_orm::{entity::*, query::*, sea_query::Expr, tests_cfg::fruit, DbBackend};
///
/// assert_eq!(
/// fruit::Entity::find()
/// .filter(Expr::col(fruit::Column::CakeId).is_null())
/// .build(DbBackend::MySql)
/// .to_string(),
/// "SELECT `fruit`.`id`, `fruit`.`name`, `fruit`.`cake_id` FROM `fruit` WHERE `cake_id` IS NULL"
/// );
/// ```
fn filter<F>(mut self, filter: F) -> Self
where
F: IntoCondition,
{
self.query().cond_where(filter.into_condition());
self
}
/// Apply a where condition using the model's primary key
fn belongs_to<M>(mut self, model: &M) -> Self
where
M: ModelTrait,
{
for key in <M::Entity as EntityTrait>::PrimaryKey::iter() {
let col = key.into_column();
self = self.filter(col.eq(model.get(col)));
}
self
}
/// Perform a check to determine table belongs to a Model through it's name alias
fn belongs_to_tbl_alias<M>(mut self, model: &M, tbl_alias: &str) -> Self
where
M: ModelTrait,
{
for key in <M::Entity as EntityTrait>::PrimaryKey::iter() {
let col = key.into_column();
let expr = Expr::tbl(Alias::new(tbl_alias), col).eq(model.get(col));
self = self.filter(expr);
}
self
}
}
pub(crate) fn join_condition(rel: RelationDef) -> SimpleExpr {
let from_tbl = unpack_table_ref(&rel.from_tbl);
let to_tbl = unpack_table_ref(&rel.to_tbl);
let owner_keys = rel.from_col;
let foreign_keys = rel.to_col;
join_tbl_on_condition(from_tbl, to_tbl, owner_keys, foreign_keys)
}
pub(crate) fn join_tbl_on_condition(
from_tbl: SeaRc<dyn Iden>,
to_tbl: SeaRc<dyn Iden>,
owner_keys: Identity,
foreign_keys: Identity,
) -> SimpleExpr {
match (owner_keys, foreign_keys) {
(Identity::Unary(o1), Identity::Unary(f1)) => {
Expr::tbl(SeaRc::clone(&from_tbl), o1).equals(SeaRc::clone(&to_tbl), f1)
}
(Identity::Binary(o1, o2), Identity::Binary(f1, f2)) => {
Expr::tbl(SeaRc::clone(&from_tbl), o1)
.equals(SeaRc::clone(&to_tbl), f1)
.and(Expr::tbl(SeaRc::clone(&from_tbl), o2).equals(SeaRc::clone(&to_tbl), f2))
}
(Identity::Ternary(o1, o2, o3), Identity::Ternary(f1, f2, f3)) => {
Expr::tbl(SeaRc::clone(&from_tbl), o1)
.equals(SeaRc::clone(&to_tbl), f1)
.and(Expr::tbl(SeaRc::clone(&from_tbl), o2).equals(SeaRc::clone(&to_tbl), f2))
.and(Expr::tbl(SeaRc::clone(&from_tbl), o3).equals(SeaRc::clone(&to_tbl), f3))
}
_ => panic!("Owner key and foreign key mismatch"),
}
}
pub(crate) fn unpack_table_ref(table_ref: &TableRef) -> DynIden {
match table_ref {
TableRef::Table(tbl) => SeaRc::clone(tbl),
TableRef::SchemaTable(_, tbl) => SeaRc::clone(tbl),
TableRef::TableAlias(tbl, _) => SeaRc::clone(tbl),
TableRef::SchemaTableAlias(_, tbl, _) => SeaRc::clone(tbl),
TableRef::SubQuery(_, tbl) => SeaRc::clone(tbl),
}
}