From 101277ddbb80ccdd4c21a19683a2b9652c76ce09 Mon Sep 17 00:00:00 2001
From: Dean Braun <72529945+bean1352@users.noreply.github.com>
Date: Thu, 4 Jun 2026 15:10:20 +0200
Subject: [PATCH] sync-config: add composite-key JOIN pattern
 (powersync-docs#395)

---
 skills/powersync/references/sync-config.md | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/skills/powersync/references/sync-config.md b/skills/powersync/references/sync-config.md
index b42569a..08f870c 100644
--- a/skills/powersync/references/sync-config.md
+++ b/skills/powersync/references/sync-config.md
@@ -218,6 +218,19 @@ streams:
       WHERE tm.user_id = auth.user_id()
 ```
 
+For composite-key joins (multiple join columns), use implicit join syntax with multiple `WHERE` equality conditions:
+
+```yaml
+streams:
+  regional_comments:
+    query: |
+      SELECT comments.*
+      FROM comments, issues
+      WHERE comments.issue_id = issues.id
+        AND comments.region = issues.region
+        AND issues.user_id = auth.user_id()
+```
+
 ### Subquery
 
 Use `WHERE id IN (SELECT ...)` for indirect access through a related table:
@@ -397,7 +410,7 @@ There are examples available for each PowerSync Client SDK.
 ### Frameworks 
 
 | Framework                 | Client Usage Reference URL                                                                                         |
-|---------------------------|--------------------------------------------------------------------------------------------------------------------|
+|---------------------------|-----------------------------------------------------------------------------------------------------------------|
 | React                     | [Client Usage](https://docs.powersync.com/sync/streams/client-usage.md#react-hooks)                                        |
 
 ## Advanced Topics