将两个顺序 SQL 查询合并为单个 SQL 查询以获取 max 和 join

Question

我有两个 SQL 顺序执行的查询。

select max(last_updated_date) as recent_date
    from TRANSACTION where quality='P' and TYPE='Car'

select * from CAR 
JOIN
(
select TRAN_ID,LAST_UPDATED_DATE from TRANSACTION 
) on TRANSACTION.TRAN_ID=CAR.ID and TRANSACTION.LAST_UPDATED_DATE=recent_date

我想通过单个查询获得相同的结果。我什么都想不出来。

Answer 1

使用可以使用标量子查询

select * 
from CAR 
JOIN
(
   select TRAN_ID,LAST_UPDATED_DATE 
   from TRANSACTION 
) t on t.TRAN_ID=CAR.ID and t.LAST_UPDATED_DATE=(select max(last_updated_date)
                               from TRANSACTION 
                               where quality='P' and TYPE='Car')

将两个顺序 SQL 查询合并为单个 SQL 查询以获取 max 和 join

Merge two sequential SQL query into a single SQL query for max and join

mysql

sql

join

merge

max