查询在MYSQL中工作但不在SQLite中(语法区别？)

Question

嗨,我有一个查询,从我的房屋表中选择所有按街道地址分组的房屋.它统计了该街道上有多少人,但也计算了另一个游说桌中引用该街道的数量.

我有查询在MYSQL中工作但是当我在我的iOS应用程序中使用SQlite尝试它时它不起作用.我不知道两者之间是否有一些语法差异？

 SELECT haddress AS hd, COUNT( * ) ,
    (
     SELECT COUNT( * ) 
     FROM canvass, house
     WHERE canvass.hid = house.hid
     AND house.haddress = hd
    )
 FROM house
 GROUP BY haddress

Answer 1

似乎你不能在SQLite的内部查询中引用列别名,所以你必须稍微改变你的内部查询以使用别名,house这样你就可以引用外部了house.haddress.更改后的查询应该适用于SQLite和MySQL;

SELECT haddress AS hd, COUNT( * ),
    (
     SELECT COUNT( * ) 
     FROM canvass, house house2
     WHERE canvass.hid = house2.hid
     AND house2.haddress = house.haddress
    )
FROM house
GROUP BY haddress