From ab53696ce1aca28a292ecb1b20967a1f687cf7a1 Mon Sep 17 00:00:00 2001
From: Huan Lin <huan.lin@airbnb.com>
Date: Mon, 15 Oct 2018 21:52:10 -0700
Subject: [PATCH] add primary key with 4 columns.

---
 Sources/SQLite/Typed/Schema.swift   | 4 ++++
 Tests/SQLiteTests/SchemaTests.swift | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/Sources/SQLite/Typed/Schema.swift b/Sources/SQLite/Typed/Schema.swift
index 62c90702..febfe68c 100644
--- a/Sources/SQLite/Typed/Schema.swift
+++ b/Sources/SQLite/Typed/Schema.swift
@@ -341,6 +341,10 @@ public final class TableBuilder {
         primaryKey([compositeA, b, c])
     }
 
+    public func primaryKey<T : Value, U : Value, V : Value, W : Value>(_ compositeA: Expression<T>, _ b: Expression<U>, _ c: Expression<V>, _ d: Expression<W>) {
+        primaryKey([compositeA, b, c, d])
+    }
+
     fileprivate func primaryKey(_ composite: [Expressible]) {
         definitions.append("PRIMARY KEY".prefix(composite))
     }
diff --git a/Tests/SQLiteTests/SchemaTests.swift b/Tests/SQLiteTests/SchemaTests.swift
index b9a08881..30646b98 100644
--- a/Tests/SQLiteTests/SchemaTests.swift
+++ b/Tests/SQLiteTests/SchemaTests.swift
@@ -545,6 +545,10 @@ class SchemaTests : XCTestCase {
             "CREATE TABLE \"table\" (PRIMARY KEY (\"int64\", \"string\", \"double\"))",
             table.create { t in t.primaryKey(int64, string, double) }
         )
+        XCTAssertEqual(
+            "CREATE TABLE \"table\" (PRIMARY KEY (\"int64\", \"string\", \"double\", \"date\"))",
+            table.create { t in t.primaryKey(int64, string, double, date) }
+        )
     }
 
     func test_unique_compilesUniqueExpression() {