postgresql JOIN有多個條件

Question

我有兩個postgres表：

worker_details_verification (verification_id BIGSERIAL, worker_id BIGINT, 
state TEXT, proofs TEXT[])
worker_details(worker_id BIGINT, name TEXT)

現在我想

    `verification_id, worker_id, proofs FROM` the table 
    `worker_details_verification`  

限制記錄`WHERE state ='Initial'

現在，除了上面的三列之外，我還希望來自worker_details表的name列，其中worker_id可用於查詢工作人員的姓名。

我嘗試了以下查詢，但沒有成功。

SELECT a.verification_id, a.worker_id, a.state, a.proofs, b.Name FROM 
worker_details_verification a FULL OUTER JOIN worker_details b ON 
a.worker_id = b.worker_id AND a.state = 'Initial';

它返回的記錄，甚至a.state不是'Initial' ，並在那里都是些錯誤的記錄name從worker_detail所以會返回NULL的worker_details_verification列。

Answer 1

在我看來，您希望使用“向左/向右”，而不是“完全外部聯接”，因為您要從Worker_Details_Verification中查找數據，然后對其進行過濾，同時還要在適用時獲取Worker_Details。

我拿了這個：

SELECT a.verification_id, a.worker_id, a.state, a.proofs, b.Name 
FROM worker_details_verification a 
     FULL OUTER JOIN worker_details b ON a.worker_id = b.worker_id AND a.state = 'Initial';

並使其成為：

SELECT a.verification_id, a.worker_id, a.state, a.proofs, b.Name 
FROM worker_details_verification a 
     LEFT OUTER JOIN worker_details b ON a.worker_id = b.worker_id 
WHERE a.state = 'Initial';

Answer 2

你有這樣嘗試過嗎？

SELECT a.verification_id, a.worker_id, a.state, a.proofs, b.Name 
FROM worker_details_verification a 
INNER JOIN worker_details b ON a.worker_id = b.worker_id
WHERE a.state = 'Initial';