[英]How to select data from multiple tables using joins/subquery properly? (PHP-MySQL)
[英]how to select sum, and count from diffrent tables using multiple joins
我需要从许多表中生成一些关于过滤器的大数据,在那里我还需要获得一些列的总和,以及像行一样的行数
我有5条记录
ID | NAME | DELETED
1 | A | 1
2 | A | 0
3 | A | 1
4 | B | 1
5 | C | 1
我有查询,
SELECT p.name, sum(p.deleted) as del, count(p.id) as numbers from products as p
join other AS b ON p.id=b.id
我需要的输出是,
The sum of deleted records
NAME | 删除| 计数
A | 2 | 3
B | 1 | 1
C | 1 | 1
尝试这个 ::
SELECT
p.name,
sum(p.deleted) as del,
count(id) as numbers
from products as p
join other AS b ON p.id=b.id
group by p.name
您不应该加入以获得结果。 这应该工作:
SELECT name, sum(deleted), count(1)
FROM products
GROUP BY name
SELECT name,
SUM(CASE WHEN deleted = 1 THEN 1 ELSE 0 END) Deletion,
COUNT(*) `COunt`
FROM products
GROUP BY name
要么
SELECT name,
SUM(deleted) Deletion,
COUNT(*) `COunt`
FROM products
GROUP BY name;
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