拥有一个非常非常大的SQL查询以及许多(可能是多余的)WHERE子句是否特别糟糕?
例如,这是我从我的Web应用程序生成的一个查询,其中所有内容都已关闭,这应该是此程序生成的最大可能查询:
SELECT *
FROM 4e_magic_items
INNER JOIN 4e_magic_item_levels
ON 4e_magic_items.id = 4e_magic_item_levels.itemid
INNER JOIN 4e_monster_sources
ON 4e_magic_items.source = 4e_monster_sources.id
WHERE (itemlevel BETWEEN 1 AND 30)
AND source!=16 AND source!=2 AND source!=5
AND source!=13 AND source!=15 AND source!=3
AND source!=4 AND source!=12 AND source!=7
AND source!=14 AND source!=11 AND source!=10
AND source!=8 AND source!=1 AND source!=6
AND source!=9 AND type!='Arms' AND type!='Feet'
AND type!='Hands' AND type!='Head'
AND type!='Neck' AND type!='Orb'
AND type!='Potion' AND type!='Ring'
AND type!='Rod' AND type!='Staff'
AND type!='Symbol' …Run Code Online (Sandbox Code Playgroud)