多列的 WHERE 子句中的 AND 條件

Question

我有兩張桌子

Table 1 = restaurants ( r_id , type , cuisine_bkup ) 
Table 2 = address ( id , r_id , location, address )

我正在應用此查詢

SELECT * 
FROM restaurants r 
RIGHT JOIN addresses a ON a.r_id = r.r_id 
WHERE r.type LIKE 'Cafe' AND a.location LIKE 'Gulberg' AND  r.cuisine_bkup LIKE 'Pizza'
GROUP BY r.r_id

它沒有給我任何結果我該怎么做我想用 AND 條件做

Answer 1

您可能需要通配符%來搜索列中的值，如下所示：

SELECT * 
FROM restaurants r 
RIGHT JOIN addresses a ON a.r_id = r.r_id 
WHERE r.type LIKE '%Cafe%' AND a.location LIKE '%Gulberg%' AND  r.cuisine_bkup LIKE '%Pizza%'
GROUP BY r.r_id

否則另一個選項（我猜是使用OR而不是AND ）

SELECT * 
FROM restaurants r 
RIGHT JOIN addresses a ON a.r_id = r.r_id 
WHERE r.type LIKE '%Cafe%' OR a.location LIKE '%Gulberg%' OR r.cuisine_bkup LIKE '%Pizza%'
GROUP BY r.r_id

（還要注意，當且僅當所有三個條件都為真時，您將獲得 AND 結果，即r.type LIKE 'Cafe' AND a.location LIKE 'Gulberg' AND r.cuisine_bkup LIKE 'Pizza' ）

Answer 2

使用%和like

WHERE r.type LIKE '%Cafe%' 
AND a.location LIKE '%Gulberg%' 
AND  r.cuisine_bkup LIKE '%Pizza%'

Answer 3

SELECT * 
FROM restaurants r 
RIGHT JOIN addresses a ON a.r_id = r.r_id AND a.location LIKE 'Gulberg'
WHERE r.type LIKE 'Cafe'  AND  r.cuisine_bkup LIKE 'Pizza'
GROUP BY r.r_id

要使 RIGHT join 工作，您必須將AND a.location LIKE 'Gulberg'移動到ON 。否則它將作為INNER JOIN起作用。

我想指出 '=' 的工作速度比LIKE快得多（如果您將字符等同）..

希望這可以幫助