[英]Using SELECT IF in WHERE clause
In the query below the SELECT statement has an IF case, if the price in table a is equal to 999999 than I set n_price to 0 otherwise the price stays the same. 在下面的查询中,SELECT语句具有IF情况,如果表a中的价格等于999999而不是我将n_price设置为0,否则价格保持不变。
What I want to know is would there be a simple way of using n_price (the updated value from the query) in the WHERE clause instead of a.price
to carry out a calculation? 我想知道的是,有一种简单的方法可以在WHERE子句中使用n_price(查询中更新的值)而不是a.price
来执行计算吗? if not what would be a simple way to retrieve the value in the WHERE clause 如果不是,那么在WHERE子句中检索值的简单方法是什么
SELECT
IF(a.price = 999999, 0, a.price) AS n_price,
l.quantity AS n_quantity,
l.condition AS n_condition
FROM b_products b
LEFT JOIN a_products a ON b.id = a.id
LEFT JOIN l_products l ON b.id = l.id
WHERE
AND ROUND((a.price/100*80) - l.price) >= (l.price/100*30)
I think this should work: 我认为这应该有效:
AND ROUND((IF(a.price = 999999, 0, a.price)/100*80) - l.price) >= (l.price/100*30)
You can't use the name n_price
you defined in the select clause. 您不能使用在select子句中定义的名称n_price
。
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