我有一个表,其中包含数组中的记录。还有另一个表有单个字符串记录。我想获取在另一个表中多次出现的记录。以下是表格;
车辆
veh_id | vehicle_types
-------+---------------------------------------
1 | {"byd_tang","volt","viper","laferrari"}
2 | {"volt","viper"}
3 | {"byd_tang","sonata","jaguarxf"}
4 | {"swift","teslax","mirai"}
5 | {"volt","viper"}
6 | {"viper","ferrariff","bmwi8","viper"}
7 | {"ferrariff","viper","viper","volt"}
vehicle_names
id | vehicle_name
-----+-----------------------
1 | byd_tang
2 | volt
3 | viper
4 | laferrari
5 | sonata
6 | jaguarxf
7 | swift
8 | teslax
9 | mirai
10 | ferrariff
11 | bmwi8
我有一个查询,它可以提供我所期望的输出,但它不是最优的,而且可能是其昂贵的查询。
这是查询:
select veh_name
from vehicle_names dsb
where (select count(*) from vehicle dsd
where dsb.veh_name = ANY (dsd.veh_types)) > 1
输出应该是:
byd_tang
volt
viper
最佳答案
一个选项是聚合查询:
SELECT
vn.id,
vn.veh_name
FROM vehicle_names vn
INNER JOIN vehicle v
ON vn. veh_name = ANY (v.veh_types)
GROUP BY
vn.id,
vn.veh_name
HAVING
COUNT(*) > 1;
这只计算出现在另一个表的两个或多个记录中的车辆名称。例如,它不会拾取出现两次或更多次的同名车辆记录。
关于sql - 查找在另一个表数组中多次出现的记录(postgres),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/57864461/