mysql - 从 REGEXP 查询返回随机行集

Question

我正在尝试编写一个 MySQL 查询，该查询基于对一组城市的 REGEXP 搜索返回一组随机行。

即...

SELECT * FROM master_rets_table 
          WHERE property_type = "Residential" and city REGEXP "(JUNO BEACH|palm beach gardens|jupiter|WEST PALM BEACH)" and listing_price > 200000 and listing_price < 500000
          GROUP BY city
          ORDER BY RAND()

好消息是这确实会为每个城市返回一个属性，但事实证明，我猜 GROUP BY 消除了查询的 RANDom 方面，因为它每次都给出相同的结果。

Answer 1

获得四个随机属性(每个城市一个)的最简单方法是使用union all:

(select *
 from master_rets_table
 where property_type = "Residential" and city = 'JUNO BEACH' and listing_price > 200000 and listing_price < 500000
 order by rand()
 limit 1
) union all
(select *
 from master_rets_table
 where property_type = "Residential" and city = 'palm beach gardens' and listing_price > 200000 and   listing_price < 500000
 order by rand()
 limit 1
) union all
(select *
 from master_rets_table
 where property_type = "Residential" and city = 'jupiter' and listing_price > 200000 and listing_price < 500000
 order by rand()
 limit 1
) union all
(select *
 from master_rets_table
 where property_type = "Residential" and city = 'WEST PALM BEACH' and listing_price > 200000 and  listing_price < 500000
 order by rand()
 limit 1
)