MySQL查詢，在where子句中使用多個具有相同名稱的表字段

Question

我有一個帶有多個聯接的select語句，每個聯接都有一個名為“ created_on”的列名，有沒有一種方法可以使查詢的where部分將檢查所有3個表？ 這是我所做的實際查詢

SELECT *
FROM household_address
JOIN catchment_area ON catchment_area.household_id = household_address.household_id
JOIN bhw ON catchment_area.bhw_id = bhw.user_username
JOIN master_list ON master_list.person_id = catchment_area.person_id
JOIN house_visits ON house_visits.household_id = household_address.household_id
WHERE catchment_area.household_id IN (
  SELECT household_address.household_id
  FROM demo.household_address
  JOIN catchment_area ON catchment_area.household_id = household_address.household_id
  JOIN previous_cases ON catchment_area.person_id = previous_cases.person_id
  JOIN active_cases ON catchment_area.person_id = active_cases.person_id
  JOIN ls_report ON ls_report.ls_household = household_address.household_name
  WHERE DATE(created_on) BETWEEN '2014-03-01' AND '2014-03-31' 
)

我正在談論的聯接是子查詢中的聯接。

Answer 1

首先，您應該像這樣為每個表名創建一個別名，以使其更易於閱讀和編寫。

SELECT *
FROM household_address AS ha
JOIN catchment_area ca ON ca.household_id = ha.household_id
JOIN bhw bh ON ca.bhw_id = bh.user_username
JOIN master_list ml ON ml.person_id = ca.person_id
JOIN house_visits hv ON hv.household_id = ha.household_id
WHERE ca.household_id IN 
(
    SELECT ha1.household_id
    FROM demo.household_address AS ha1
    JOIN ca1 ON ca1.household_id = ha1.household_id
    JOIN previous_cases pc ON ca1.person_id = pc.person_id
    JOIN active_cases ac ON ca1.person_id = ac.person_id
    JOIN ls_report ls_r ON ls_r.ls_household = ha1.household_name
    WHERE DATE(ha1.created_on)  BETWEEN '2014-03-01' AND '2014-03-31' 
      AND DATE(ca1.created_on)  BETWEEN '2014-03-01' AND '2014-03-31'
      AND DATE(pc.created_on)   BETWEEN '2014-03-01' AND '2014-03-31'
      AND DATE(ac.created_on)   BETWEEN '2014-03-01' AND '2014-03-31'
      AND DATE(ls_r.created_on) BETWEEN '2014-03-01' AND '2014-03-31'
)

對於創建日期的每個條件，您必須告訴它WHERE（table_name.created_on BETWEEN .....）

對每個表都這樣做，這應該工作

Answer 2

嘗試將別名與其他WHERE子句一起使用。

SELECT 
    *
FROM household_address
JOIN catchment_area ON catchment_area.household_id = household_address.household_id
JOIN bhw ON catchment_area.bhw_id = bhw.user_username
JOIN master_list ON master_list.person_id = catchment_area.person_id
JOIN house_visits ON house_visits.household_id = household_address.household_id
WHERE catchment_area.household_id IN (
  SELECT household_address.household_id
  FROM demo.household_address ha
  JOIN catchment_area ca ON ca.household_id = ha.household_id
  JOIN previous_cases pc ON ca.person_id = pc.person_id
  JOIN active_cases ac ON ca.person_id = ac.person_id
  JOIN ls_report ls_r ON ls_r.ls_household = ha.household_name
  WHERE DATE(ha.created_on) BETWEEN '2014-03-01' AND '2014-03-31' 
  AND DATE(ca.created_on) BETWEEN '2014-03-01' AND '2014-03-31' 
  AND DATE(pc.created_on) BETWEEN '2014-03-01' AND '2014-03-31' 
)

我實際上不知道哪三個表具有“ created_on”字段，因此我以household_address，catchment_area和previous_cases為例。 將其更改為您實際要搜索的內容。

（也應該為所有表名加上別名）