SQL 交集 - 语法错误

Question

我正在尝试搜索从伦敦出发并抵达巴黎的航班。有关城市的信息位于 Airport 表中，而出发和到达机场的缩写位于 Flight 中。

这是我的问题代码：

SELECT flightNo,flightCompany
FROM Flight
JOIN Airport
ON Airport.airportId=Flight.depAirport
WHERE Airport.city='London'

INTERSECT

SELECT flightNo,flightCompany
FROM Flight
JOIN Airport
ON Airport.airportId=Flight.arrAirport
WHERE Airport.city='Paris';

它返回 3 个错误 -

• SQL 状态：HY000 错误代码：1000 SQL 语句语法错误
• SQL 状态：HY000 错误代码：1000
• SQL 状态：HY000 错误代码：1000 语法错误，意外 $end，期望 BETWEEN 或 IN 或 SQL_TOKEN_LIKE

Answer 1

改用JOINs 重写查询怎么样？

SELECT f.flightNo, f.flightCompany
FROM Flight f JOIN
     Airport ad
     ON ad.airportId = f.depAirport AND ad.city = 'London' JOIN
     Airport aa
     ON aa.airportId = f.arrAirport AND aa.city = 'Paris';

或者，使用EXISTS？

SELECT f.*
FROM Flight f
WHERE EXISTS (SELECT 1
              FROM Airport ad
              WHERE ad.airportId = f.depAirport AND ad.city = 'London'
             ) AND
      EXISTS (SELECT 1
              FROM Airport aa
              WHERE aa.airportId = f.arrAirport AND aa.city = 'Paris'
             );

Answer 2

使用默认的 LibreOffice Base / HSQLDB 1.8 设置引用规则和区分大小写是很棘手的。以下是您需要做的：

SELECT "flightNo","flightCompany"
FROM "Flight"
JOIN "Airport"
ON "Airport"."airportId"="Flight"."depAirport"
WHERE "Airport"."city"='London'
INTERSECT
SELECT "flightNo","flightCompany"
FROM "Flight"
JOIN "Airport"
ON "Airport"."airportId"="Flight"."arrAirport"
WHERE "Airport"."city"='Paris';

或者更好，修改戈登的回答如下：

SELECT F."flightNo", F."flightCompany"
FROM "Flight" F JOIN
     "Airport" AD
     ON AD."airportId" = F."depAirport" AND AD."city" = 'London' JOIN
     "Airport" AA
     ON AA."airportId" = F."arrAirport" AND AA."city" = 'Paris';