From 92ac1098cb74fb804ccf20a52c1664847c5e494d Mon Sep 17 00:00:00 2001
From: Chris Tsang <tyt2y7@gmail.com>
Date: Wed, 19 May 2021 21:37:56 +0800
Subject: [PATCH] Identity Tuple

---
 src/entity/identity.rs | 25 ++++++++++++++-----------
 src/query/helper.rs    |  8 +++++++-
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/src/entity/identity.rs b/src/entity/identity.rs
index 303956aa..516f5bef 100644
--- a/src/entity/identity.rs
+++ b/src/entity/identity.rs
@@ -1,30 +1,33 @@
 use sea_query::{Iden, IntoIden};
+use crate::{IdenStatic};
 use std::rc::Rc;
 
 #[derive(Debug, Clone)]
 pub enum Identity {
     Unary(Rc<dyn Iden>),
-    // Binary((Rc<dyn Iden>, Rc<dyn Iden>)),
-    // Ternary((Rc<dyn Iden>, Rc<dyn Iden>, Rc<dyn Iden>)),
+    Binary(Rc<dyn Iden>, Rc<dyn Iden>),
+    // Ternary(Rc<dyn Iden>, Rc<dyn Iden>, Rc<dyn Iden>),
 }
 
 pub trait IntoIdentity {
     fn into_identity(self) -> Identity;
 }
 
-impl Identity {
-    pub fn into_iden(self) -> Rc<dyn Iden> {
-        match self {
-            Self::Unary(iden) => iden,
-        }
-    }
-}
-
 impl<T> IntoIdentity for T
 where
-    T: IntoIden,
+    T: IdenStatic,
 {
     fn into_identity(self) -> Identity {
         Identity::Unary(self.into_iden())
     }
 }
+
+impl<T, C> IntoIdentity for (T, C)
+where
+    T: IdenStatic,
+    C: IdenStatic,
+{
+    fn into_identity(self) -> Identity {
+        Identity::Binary(self.0.into_iden(), self.1.into_iden())
+    }
+}
diff --git a/src/query/helper.rs b/src/query/helper.rs
index 86c3f1e9..8da13e75 100644
--- a/src/query/helper.rs
+++ b/src/query/helper.rs
@@ -219,6 +219,12 @@ fn join_condition(rel: RelationDef) -> SimpleExpr {
     match (owner_keys, foreign_keys) {
         (Identity::Unary(o1), Identity::Unary(f1)) => {
             Expr::tbl(Rc::clone(&from_tbl), o1).equals(Rc::clone(&to_tbl), f1)
-        } // _ => panic!("Owner key and foreign key mismatch"),
+        }
+        (Identity::Binary(o1, o2), Identity::Binary(f1, f2)) => {
+            Expr::tbl(Rc::clone(&from_tbl), o1).equals(Rc::clone(&to_tbl), f1).and(
+                Expr::tbl(Rc::clone(&from_tbl), o2).equals(Rc::clone(&to_tbl), f2)
+            )
+        }
+        _ => panic!("Owner key and foreign key mismatch"),
     }
 }