initial commit

pkg/services/sqlstore/migrations/short_url_mig.go

@@ -28,4 +28,21 @@ func addShortURLMigrations(mg *Migrator) {
 	mg.AddMigration("alter table short_url alter column created_by type to bigint", NewRawSQLMigration("").
 		Mysql("ALTER TABLE short_url MODIFY created_by BIGINT;").
 		Postgres("ALTER TABLE short_url ALTER COLUMN created_by TYPE BIGINT;"))
+
+	// Add signature column for de-duplication
+	shortURLTable := Table{Name: "short_url"}
+	mg.AddMigration("add signature column to short_url table", NewAddColumnMigration(shortURLTable, &Column{
+		Name:     "signature",
+		Type:     DB_Varchar,
+		Length:   64,
+		Nullable: true,
+	}))
+
+	// Add unique index on (org_id, signature) with NULL handling
+	// PostgreSQL needs a partial unique index to handle NULLs correctly
+	// MySQL/SQLite allow multiple NULLs in unique indexes, which is fine
+	mg.AddMigration("add unique index short_url.org_id-signature", NewRawSQLMigration("").
+		Postgres("CREATE UNIQUE INDEX IF NOT EXISTS UQE_short_url_org_id_signature ON short_url(org_id, signature) WHERE signature IS NOT NULL;").
+		Mysql("CREATE UNIQUE INDEX UQE_short_url_org_id_signature ON short_url(org_id, signature);").
+		SQLite("CREATE UNIQUE INDEX IF NOT EXISTS UQE_short_url_org_id_signature ON short_url(org_id, signature);"))
 }