db refactor

src/ORM/_migrations/UniqueNonceIndex.ts

@@ -0,0 +1,15 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+export class UniqueNonceIndex implements MigrationInterface {
+
+    public async up(queryRunner: QueryRunner): Promise<void> {
+        await queryRunner.query(
+            `CREATE UNIQUE INDEX "IDX_unique_nonce" ON "client_entity" ("sessionId") WHERE "deletedAt" IS NOT NULL`
+        );
+    }
+
+    public async down(queryRunner: QueryRunner): Promise<void> {
+        await queryRunner.query(`DROP INDEX "IDX_unique_nonce"`);
+    }
+
+}