如何在slick + postgresql上进行分页选择 [英] how to get paginated select on slick + postgresql

问题描述

在带有slick 3的Postgresql数据库中，进行分页的最佳方法是什么?

In a postgresql database, with slick 3, what's the best way to have pagination?

• 获取所有行并使用scala进行分页(似乎不是很有效)?
• 具有限制和偏移量的静态查询?
• 还有其他方法吗?

推荐答案

您可以在TableQuery对象上使用take和drop方法.它们将在结果SQL查询中转换为limit和offset:

You can use take and drop methods on TableQuery objects. They will be translated to limit and offset in the resulting SQL query:

val users: TableQuery[UsersTable] = UsersTable.query

val firstPartOfUsers  = users.drop(0).take(25).result
val secondPartOfUsers = users.drop(25).take(25).result

这两个操作将转换为以下SQL查询:

Those two actions will be translated to the following SQL queries:

select "name", "email", "id" from "users" limit 25 offset 0
select "name", "email", "id" from "users" limit 25 offset 25

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