如何使用 Doobie 在插入语句中获得可选结果? [英] How to get optional result in insert statements with Doobie?

问题描述

我有一个可选的插入查询:

val q = sql"insert into some_table (some_field) select 42 where ...(some condition)"

运行此查询:

q.update.withUniqueGeneratedKeys[Option[Long]]("id")

失败

<块引用>

结果集已用尽:预计会有更多行

则 condition 为假.

如何使用 Doobie 从插入语句中获取 Optional[Long] 结果?

<小时>

UPD

.withGeneratedKeys[Long]("id") 仅给出 Long 以供理解

val q = sql"insert into some_table (some_field) select 42 where ...(some condition)"为了 {id <- q.update.withGeneratedKeys[Long]("id")//id 很长_ <- if (<id is present>) <其他一些插入>其他<什么都没有>产量 ID

如何查看id?

解决方案

正如@Thilo 所评论的，您可以使用 withGeneratedKeys 来返回一个 Stream[F, Long] (其中 F 是您的效果类型)

val result = q.update.withGeneratedKeys[Long]("id")

这是文档.>

I have an optional insert query:

val q = sql"insert into some_table (some_field) select 42 where ...(some condition)"

Running this query with:

q.update.withUniqueGeneratedKeys[Option[Long]]("id")

fails with

Result set exhausted: more rows expected

then condition is false.

How to get Optional[Long] result from insert statements with Doobie?

---

UPD

.withGeneratedKeys[Long]("id") gives just Long in for comprehension

val q = sql"insert into some_table (some_field) select 42 where ...(some condition)"
for {
  id <- q.update.withGeneratedKeys[Long]("id")   // id is long
  _ <- if (<id is present>) <some other inserts> else <nothing>
} yield id

How to check id?

解决方案

As @Thilo commented, you can use the use withGeneratedKeys which gives you back a Stream[F, Long] (where F is your effect type)

val result = q.update.withGeneratedKeys[Long]("id")

Here is the doc.

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