Method as

packages/sql/src/query/QueryBuilder.ts:2709–2732

(aliasOrTargetEntity: string | EntityName<T>, alias?: EntityKey<T>)

  as<T>(targetEntity: EntityName<T>, alias: EntityKey<T>): NativeQueryBuilder;

  as<T>(aliasOrTargetEntity: string | EntityName<T>, alias?: EntityKey<T>): NativeQueryBuilder {
    const qb = this.getNativeQuery();
    let finalAlias = aliasOrTargetEntity as string;

    /* v8 ignore next */
    if (typeof aliasOrTargetEntity === 'string' && aliasOrTargetEntity.includes('.')) {
      throw new Error(
        'qb.as(alias) no longer supports target entity name prefix, use qb.as(TargetEntity, key) signature instead',
      );
    }

    if (alias) {
      const meta = this.metadata.get(aliasOrTargetEntity as EntityName<T>);
      /* v8 ignore next */
      finalAlias = meta.properties[alias]?.fieldNames[0] ?? alias;
    }

    qb.as(finalAlias);

    // tag the instance, so it is possible to detect it easily
    Object.defineProperty(qb, '__as', { enumerable: false, value: finalAlias });

    return qb;
  }

  /**
   * Combines the current query with one or more other queries using `UNION ALL`.