PostgreSQL的：從選擇更新總是失敗

Question

請幫幫忙，

我會在account_move_line（列tax_number）與價值account_invoice_line（列no_pajak）更新的價值。 但它總是返回空。

這是我的代碼：

update account_move_line aml set tax_number = (
    select no_pajak as tax_number from account_invoice_line 
    where invoice_id = aml.invoice_id and no_pajak is not NULL 
) 
where tax_number is NULL and date > '2017-08-01' 

非常感謝您

Answer 1

我不知道是否可以使用橫向加入這種方式，因此與CTE重寫了它：

with u as (
    select no_pajak, invoice_id id 
    from account_invoice_line 
    join account_move_line aml on invoice_id = aml.invoice_id and no_pajak is not NULL 
) 
update account_move_line aml set tax_number = no_pajak 
from u 
where invoice_id = id 
and tax_number is NULL and date > '2017-08-01' 

應該工作，雖然看起來過於複雜