Question

此查询有效：

  var query = knex('project_member')
    .join('project', 'project_member.pm_project', '=', 'project.prj_id')
    .join('users', 'project_member.pm_user', '=', 'users.us_id')
    .where({
      prj_number: inputs.params.prj_number
    })
    .select('pm_project', 'us_name', 'us_alias');

query.toString（）给出：

select "pm_project", "us_name", "us_alias" from "project_member" inner join "project" on "project_member"."pm_project" = "project"."prj_id" inner join "users" on "project_member"."pm_user" = "users"."us_id" where "prj_number" = '4026305'

此查询不起作用：

  var query = knex('project_member')
    .join('project', 'project_member.pm_project', '=', 'project.prj_id')
    .where({
      prj_number: inputs.params.prj_number,
      pm_user: inputs.params.pm_user
    })
    .del();

query.toString（）给出：

delete from "project_member" where "prj_number" = '4026305' and "pm_user" = '1'

无法在删除查询中使用联接？您是否必须单独进行查询以加入它们？

Answer 1

似乎删除连接无法正常工作（可能是由于各种数据库的删除连接语法非常不同），但您应该能够将查询重写为简单的IN查询;

DELETE FROM project_member
WHERE pm_user = <pm user>
AND pm_project IN (
  SELECT prj_id FROM project WHERE prj_number = <prj_number>
)

...应该由（未经测试的）生成;

knex('project_member')
  .where('pm_user', inputs.params.pm_user)
  .whereIn('pm_project', function() {
    this.select('prj_id')
        .from('project')
        .where('prj_number', inputs.params.prj_number);
  })
  .del()

...并且始终记得在数据库上从Internet上的随机用户运行可能具有破坏性的SQL之前备份数据; - ）

内部连接删除查询，Node JS，Knex JS

1 个答案: