From e7ae287d2fec665a26144308e104e778a7ad5071 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Wed, 12 Jan 2022 12:46:05 +0000
Subject: [PATCH] database: always include table name in SELECT

When JOINs are performed on the auto-generated SELECT query,
multiple tables may have the same field names. For instance, in
lists.sr.ht the "list" and "subscription" tables both have an "id"
column. When performing a "mailingLists" GraphQL query this results
in this error:

    pq: column reference "id" is ambiguous

The old query looks like this:

    SELECT "description", "name", "id", "owner_id", "updated", COALESCE(
    access.permissions,
    CASE WHEN list.owner_id = $1
    THEN $2
    ELSE CASE WHEN sub.id IS NOT NULL
    	THEN list.subscriber_permissions
    	ELSE null END
    END,
    list.nonsubscriber_permissions | list.account_permissions), access.id AS access_id, sub.id AS subscription_id FROM list LEFT JOIN access ON
    access.list_id = list.id AND
    access.user_id = $3 LEFT JOIN subscription sub ON
    sub.list_id = list.id AND
    sub.user_id = $4 WHERE list.owner_id = $5 ORDER BY "updated" DESC LIMIT 26

The new query looks like this:

    SELECT "description", "name", "list"."id", "list"."owner_id", "list"."updated", COALESCE(
    access.permissions,
    CASE WHEN list.owner_id = $1
    THEN $2
    ELSE CASE WHEN sub.id IS NOT NULL
    	THEN list.subscriber_permissions
    	ELSE null END
    END,
    list.nonsubscriber_permissions | list.account_permissions), access.id AS access_id, sub.id AS subscription_id FROM list LEFT JOIN access ON
    access.list_id = list.id AND
    access.user_id = $3 LEFT JOIN subscription sub ON
    sub.list_id = list.id AND
    sub.user_id = $4 WHERE list.owner_id = $5 ORDER BY "updated" DESC LIMIT 26
---
 database/ql.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/database/ql.go b/database/ql.go
index 58e6fdf155e10d8c3463582974c01ce00e5d326b..dc9ddaaae911b7a2e517ec9c8d7a5b969349487b 100644
--- a/database/ql.go
+++ b/database/ql.go
@@ -90,7 +90,11 @@ func Columns(ctx context.Context, m Model) []string {
 	}
 
 	for _, field := range m.Fields().Anonymous() {
-		columns = append(columns, WithAlias(m.Alias(), field.SQL))
+		alias := m.Alias()
+		if alias == "" {
+			alias = m.Table()
+		}
+		columns = append(columns, WithAlias(alias, field.SQL))
 	}
 
 	return columns