MySQL-＃1066-非唯一表/别名：具有多个内部联接的“组件”

Question

I have this query and I am getting error #1066 - Not unique table/alias: 'components' . What seems to be the issue?

SELECT COUNT(*) FROM `products`, `components`, `tradeNames` 
INNER JOIN `componentsMap` ON componentsMap.product_id = product.id 
INNER JOIN `components` ON componentsMap.component_id = components.id 
INNER JOIN `tradeNamesMap` ON .tradeNamesMap.product_id = products.id 
INNER JOIN `tradeNames` ON tradeNamesMap.tradeName_id = tradeNames.id 
WHERE (((((LOWER(inci) LIKE '%abies%') 
          OR (trade_name.LOWER(name) LIKE '%abies%')) 
         OR (components.LOWER(no_cas)='abies')) 
        OR (components.LOWER(no_einecs)='abies')) 
       OR (components.LOWER(name)='abies'))
AND (`published`=1) 
ORDER BY `trade_name`.`name` DESC

Answer 1

You don't need to list the tables before the INNER JOIN s. In fact, simply don't ever use commas in the FROM clause. So:

SELECT COUNT(*)
FROM `products`
INNER JOIN `componentsMap` ON componentsMap.product_id = product.id 
INNER JOIN `components` ON componentsMap.component_id = components.id 
INNER JOIN `tradeNamesMap` ON tradeNamesMap.product_id = products.id 
INNER JOIN `tradeNames` ON tradeNamesMap.tradeName_id = tradeNames.id 
WHERE (((((LOWER(inci) LIKE '%abies%') 
          OR (trade_name.LOWER(name) LIKE '%abies%')) 
         OR (components.LOWER(no_cas)='abies')) 
        OR (components.LOWER(no_einecs)='abies')) 
       OR (components.LOWER(name)='abies'))
AND (`published`=1) 
ORDER BY `trade_name`.`name` DESC;

The above query only returns one row because of the COUNT() . The order by suggests that you actually want this information for each trade_name.name . If so, you need a GROUP BY :

SELECT tn.name, COUNT(*)
FROM `products` p INNER JOIN
     `componentsMap cm
     ON cm.product_id = p.id INNER JOIN
     `components` c
     ON cm.component_id = c.id INNER JOIN
     `tradeNamesMap` tnm
     ON tnm.product_id = p.id INNER JOIN
     `tradeNames` tn
     ON tnm.tradeName_id = tn.id 
WHERE ((LOWER(inci) LIKE '%abies%') OR
       (tn.LOWER(name) LIKE '%abies%') OR
       (c.LOWER(no_cas)='abies') OR
       (c.LOWER(no_einecs)='abies') OR
       (c.LOWER(name)='abies')
      ) AND
      (`published` = 1) 
GROUP BY tn.name
ORDER BY tn.`name` DESC

Answer 2

INNER JOIN `[components]` ON componentsMap.component_id = components.id 

AND

SELECT COUNT(*) FROM `products`, [`components`], `tradeNames` 

Two components are there.

Answer 3

Just guessing, and untested, but I suspect that something like this would do what you're after...

SELECT n.name
     , COUNT(*)
  FROM products p
  JOIN componentsMap pc
    ON pc.product_id = p.id 
  JOIN components c
    ON c.id = pc.component_id 
  JOIN tradeNamesMap pn
    ON pn.product_id = p.id 
  JOIN tradeNames n
    ON n.id = pn.tradeName_id 
 WHERE 
     ( inci LIKE '%abies%'
    OR n.name LIKE '%abies%'
    OR 'abies' IN (c.no_cas,c.no_einecs,c.name)
     )
   AND published = 1
 GROUP
    BY n.name
 ORDER 
    BY n.name DESC