php - 在括号内使用 COALESCE 错误

Question

select 
tele_plan.id as value,
tele_plan.plan_name as label,
tele_plan.plan_cost as c,
tele_plan.plan_details as d,
COALESCE ( tele_plan.plan_cost - sum(tele_payment_items.amount) as  balance ,0) from `tele_plan_select` 
    inner join `tele_plan` on `tele_plan`.`id` = `tele_plan_select`.`teleplan_id`
    left join `tele_payment_defs` on `tele_payment_defs`.`telereg_id` = `tele_plan_select`.`telereg_id` 
    left join `tele_payment_items` on `tele_payment_items`.`telepaymentdefs_id` = `tele_payment_defs`.`id` 
    and
    `tele_payment_items`.`teleplan_id` = `tele_plan`.`id` 
    where `tele_plan_select`.`telereg_id` = 9
    group by `tele_plan`.`id`

我在这里使用 Laravel 框架。我猜这里的问题在于COALESCE。我试图通过减去两列值来找到平衡。如果没有返回任何内容作为 balance ，则应将其设置为 0，这就是我正在尝试做的事情。

Answer 1

COALESCE 的用法是错误的。改变它就像

COALESCE (tele_plan.plan_cost, 0) - COALESCE(SUM(tele_payment_items.amount), 0) as  balance