Loopback Mysql连接器自定义查询结果到字段值

Question

I use Loopback 3 with Mysql. We have dynamic datamodel use. For example UserAnswers containing type like 'admin' or 'user'. I want to add count of answers to countOfAnswers field for types.

Like: type 'admin' has 5 answers. type 'user' has 3 answers.

I need to count type of answers before save to get current index for answers. Like 'Select * from UserAnswers where type = "admin"' and insert it to field value.

What is the best way to do counting or custom sql. Operation hook mayby? Or could I use custom field defination in model?

Answer 1

LoopBack provides count endpoint out of the box. Just create UserAnswers model mapped to your database table and then make the following request:

GET /api/UserAnswers/count?where[type]=admin

Learn more in LoopBack docs here: Get instance count .

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Regarding custom SQL queries: it is possible to execute arbitrary SQL query by calling myModel.dataSource.connector.execute , see the docs: Executing native SQL .