public-pool/src/ORM/_migrations/UniqueNonceIndex.ts

import { MigrationInterface, QueryRunner } from 'typeorm';

export class UniqueNonceIndex implements MigrationInterface {

    public async up(queryRunner: QueryRunner): Promise<void> {
        await queryRunner.query(
            `CREATE UNIQUE INDEX IF NOT EXISTS "IDX_unique_nonce" ON "client_entity" ("sessionId") WHERE "deletedAt" IS NULL`
        );
    }

    public async down(queryRunner: QueryRunner): Promise<void> {
        await queryRunner.query(`DROP INDEX IF EXISTS "IDX_unique_nonce"`);
    }

}