Question

1. SELECT 
2.  (SELECT SUM(count) FROM _ERP_재고 as jego WHERE jego.goodsno=link.goodsno) as tt, 
3.  (SELECT catnm FROM gd_category WHERE category=LEFT(link.category, 3)) as cate1, 
4.  (SELECT catnm FROM gd_category WHERE category=LEFT(link.category, 6)) as cate2 
5. FROM gd_goods as goods, gd_goods_link as link, _ERP_재고 as jego 
6. WHERE link.goodsno=goods.goodsno 
7. AND jego.goodsno=link.goodsno 
8. AND (SELECT SUM(count) FROM _ERP_재고 as jego WHERE jego.goodsno=link.goodsno) > 0 
9. AND link.category LIKE '009%' GROUP BY goods.goodsno

我提出了不恰当的查询，因为第2行与第8行相同如果我用tt（第2行的别名）替换第8行中的子选择，则会发生错误请让我知道如何摆脱第二次调用子查询。

Answer 1

您不能在WHERE子句中使用别名。相反，您必须使用HAVING。

1. SELECT 
2.  (SELECT SUM(count) FROM _ERP_재고 as jego WHERE jego.goodsno=link.goodsno) as tt, 
3.  (SELECT catnm FROM gd_category WHERE category=LEFT(link.category, 3)) as cate1, 
4.  (SELECT catnm FROM gd_category WHERE category=LEFT(link.category, 6)) as cate2 
5. FROM gd_goods as goods, gd_goods_link as link, _ERP_재고 as jego 
6. WHERE link.goodsno=goods.goodsno 
7. AND jego.goodsno=link.goodsno 
8. AND link.category LIKE '009%' GROUP BY goods.goodsno
9. HAVING tt > 0

请让我知道mysql查询：where子句中的别名

1 个答案: